WorldWideScience

Sample records for active trp radical

  1. Spectroscopic evidence for an engineered, catalytically active Trp radical that creates the unique reactivity of lignin peroxidase.

    Science.gov (United States)

    Smith, Andrew T; Doyle, Wendy A; Dorlet, Pierre; Ivancich, Anabella

    2009-09-22

    The surface oxidation site (Trp-171) in lignin peroxidase (LiP) required for the reaction with veratryl alcohol a high-redox-potential (1.4 V) substrate, was engineered into Coprinus cinereus peroxidase (CiP) by introducing a Trp residue into a heme peroxidase that has similar protein fold but lacks this activity. To create the catalytic activity toward veratryl alcohol in CiP, it was necessary to reproduce the Trp site and its negatively charged microenvironment by means of a triple mutation. The resulting D179W+R258E+R272D variant was characterized by multifrequency EPR spectroscopy. The spectra unequivocally showed that a new Trp radical [g values of g(x) = 2.0035(5), g(y) = 2.0027(5), and g(z) = 2.0022(1)] was formed after the [Fe(IV)=O Por(*+)] intermediate, as a result of intramolecular electron transfer between Trp-179 and the porphyrin. Also, the EPR characterization crucially showed that [Fe(IV)=O Trp-179(*)] was the reactive intermediate with veratryl alcohol. Accordingly, our work shows that it is necessary to take into account the physicochemical properties of the radical, fine-tuned by the microenvironment, as well as those of the preceding [Fe(IV)=O Por(*+)] intermediate to engineer a catalytically competent Trp site for a given substrate. Manipulation of the microenvironment of the Trp-171 site in LiP allowed the detection by EPR spectroscopy of the Trp-171(*), for which direct evidence has been missing so far. Our work also highlights the role of Trp residues as tunable redox-active cofactors for enzyme catalysis in the context of peroxidases with a unique reactivity toward recalcitrant substrates that require oxidation potentials not realized at the heme site.

  2. Opportunistic activation of TRP receptors by endogenous lipids: exploiting lipidomics to understand TRP receptor cellular communication.

    Science.gov (United States)

    Bradshaw, Heather B; Raboune, Siham; Hollis, Jennifer L

    2013-03-19

    Transient receptor potential channels (TRPs) form a large family of ubiquitous non-selective cation channels that function as cellular sensors and in many cases regulate intracellular calcium. Identification of the endogenous ligands that activate these TRP receptors is still under intense investigation with the majority of these channels still remaining "orphans." That these channels respond to a variety of external stimuli (e.g. plant-derived lipids, changes in temperature, and changes in pH) provides a framework for their abilities as cellular sensors, however, the mechanism of direct activation is still under much debate and research. In the cases where endogenous ligands (predominately lipids) have shown direct activation of a channel, multiple ligands have been shown to activate the same channel suggesting that these receptors are "promiscuous" in nature. Lipidomics of a growing class of endogenous lipids, N-acyl amides, the most famous of which is N-arachidonoyl ethanolamine (the endogenous cannabinoid, Anandamide) is providing a novel set of ligands that have been shown to activate some members of the TRP family and have the potential to deorphanize many more. Here it is argued that activation of TRPV receptors, a subset of the larger family of TRPs, by multiple endogenous lipids that are structurally analogous is a model system to drive our understanding that many TRP receptors are not promiscuous, but are more characteristically "opportunistic" in nature; exploiting the structural similarity and biosynthesis of a narrow range of analogous endogenous lipids. In addition, this manuscript will compare the activation properties of TRPC5 to the activity profile of an "orphan" lipid, N-palmitoyl glycine; further demonstrating that lipidomics aimed at expanding our knowledge of the family of N-acyl amides has the potential to provide novel avenues of research for TRP receptors. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Antioxidant and antiglycation activities of the synthesised dipeptide, Asn-Trp, derived from computer-aided simulation of yam dioscorin hydrolysis and its analogue, Gln-Trp.

    Science.gov (United States)

    Han, Chuan-Hsiao; Lin, Yin-Shiou; Lin, Shyr-Yi; Hou, Wen-Chi

    2014-03-15

    Previous studies have shown that the Trp residue contributes to a high oxygen radical absorbance capacity (ORAC). Therefore, in this study, a Trp-containing dipeptide derived from a computer-aided simulation of pepsin hydrolysis of the yam tuber, dioscorin-namely, Asn-Trp (NW), and its analogue, Gln-Trp (QW)-were synthesised to compare their antioxidant and antiglycation activities with carnosine, homocarnosine, or glutathione (GSH). The antioxidant assays included hydroxyl radical-scavenging activity, anti-AAPH-induced hemolysis, and ORAC activity. NW had a significantly higher antioxidant activity than had QW and performed much better than carnosine, homocarnosine, or GSH. Using bovine serum albumin (BSA)/galactose or BSA/glucose as experimental models, NW had better antiglycation effects than had QW, as detected by an anti-N(ε)-(carboxymethyl)lysine (anti-CML) antibody. Moreover, NW and QW (50-200 μM) showed protection against methylglyoxal-induced cell deaths in human umbilical vein endothelial cells. These results suggest that NW, derived from computer-aided simulation of dioscorin hydrolysis, exhibits antioxidant and antiglycation activities, which thus shows the benefits of the yam tuber as an antioxidant-rich food. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Pulse radiolysis studies of intramolecular electron transfer in model peptides and proteins. 7. Trp -> TyrO radical transformation in hen egg-white lysozyme. Effects of pH, temperature, Trp62 oxidation and inhibitor binding

    DEFF Research Database (Denmark)

    Bobrowski, K.; Holcman, J.; Poznanski, J.

    1997-01-01

    Intramolecular long-range electron transfer (LRET) in hen egg-white lysozyme (HEWL) accompanying Trp --> TyrO radical transformation was investigated in aqueous solution by pulse radiolysis as a function of pH (5.2-7.4) and temperature (283-328K). The reaction was induced by highly selective...... below its denaturation temperature. Selective oxidation by ozone of the Trp62 indole side-chain in HEWL to N'-formylkynurenine (NFKyn62-HEWL) caused a large drop in the initial yield of Trp(.) radicals, G(Trp(.))(i). This was accompanied by a relatively small decrease in k(5) but selective oxidation...

  5. A structural view of ligand-dependent activation in thermoTRP channels

    Directory of Open Access Journals (Sweden)

    Ximena eSteinberg

    2014-05-01

    Full Text Available Transient Receptor Potential (TRP proteins are a large family of ion channels, grouped intoseven sub-families. Although great advances have been made regarding the activation andmodulation of TRP channel activity, detailed molecular mechanisms governing TRPchannel gating are still needed. Sensitive to electric, chemical, mechanical, and thermalcues, TRP channels are tightly associated with the detection and integration of sensoryinput, emerging as a model to study the polymodal activation of ion channel proteins.Among TRP channels, the temperature-activated kind constitute a subgroup by itself,formed by Vanilloid receptors 1-4, Melastatin receptors 2, 4, 5 and 8, TRPC5, and TRPA1.Some of the so-called thermoTRP channels participate in the detection of noxious stimulimaking them an interesting pharmacological target for the treatment of pain. However, thepoor specificity of the compounds available in the market represents an important obstacleto overcome. Understanding the molecular mechanics underlying ligand-dependentmodulation of TRP channels may help with the rational design of novel syntheticanalgesics. The present review focuses on the structural basis of ligand-dependentactivation of TRPV1 and TRPM8 channels. Special attention is drawn to the dissection ofligand-binding sites within TRPV1, PIP 2 -dependent modulation of TRP channels, and thestructure of natural and synthetic ligands.

  6. Membrane-tethered peptides patterned after the TRP domain (TRPducins) selectively inhibit TRPV1 channel activity.

    Science.gov (United States)

    Valente, Pierluigi; Fernández-Carvajal, Asia; Camprubí-Robles, María; Gomis, Ana; Quirce, Susana; Viana, Félix; Fernández-Ballester, Gregorio; González-Ros, José M; Belmonte, Carlos; Planells-Cases, Rosa; Ferrer-Montiel, Antonio

    2011-05-01

    The transient receptor potential vanilloid 1 (TRPV1) channel is a thermosensory receptor implicated in diverse physiological and pathological processes. The TRP domain, a highly conserved region in the C terminus adjacent to the internal channel gate, is critical for subunit tetramerization and channel gating. Here, we show that cell-penetrating, membrane-anchored peptides patterned after this protein domain are moderate and selective TRPV1 antagonists both in vitro and in vivo, blocking receptor activity in intact rat primary sensory neurons and their peripheral axons with mean decline time of 30 min. The most potent lipopeptide, TRP-p5, blocked all modes of TRPV1 gating with micromolar efficacy (IC(50)100 μM). TRP-p5 did not affect the capsaicin sensitivity of the vanilloid receptor. Our data suggest that TRP-p5 interferes with protein-protein interactions at the level of the TRP domain that are essential for the "conformational" change that leads to gate opening. Therefore, these palmitoylated peptides, which we termed TRPducins, are noncompetitive, voltage-independent, sequence-specific TRPV1 blockers. Our findings indicate that TRPducin-like peptides may embody a novel molecular strategy that can be exploited to generate a selective pharmacological arsenal for the TRP superfamily of ion channels.

  7. Structure-activity relationship of Trp-containing analogs of the antimicrobial peptide gomesin.

    Science.gov (United States)

    Domingues, Tatiana M; Buri, Marcus V; Daffre, Sirlei; Campana, Patricia T; Riske, Karin A; Miranda, Antonio

    2014-06-01

    Gomesin (Gm) has a broad antimicrobial activity making it of great interest for development of drugs. In this study, we analyzed three Gm analogs, [Trp(1) ]-Gm, [Trp(7) ]-Gm, and [Trp(9) ]-Gm, in an attempt to gain insight into the contributions of different regions of the peptide sequence to its activity. The incorporation of the tryptophan residue in different positions has no effect on the antimicrobial and hemolytic activities of the Gm analogs in relation to Gm. Spectroscopic studies (circular dichroism, fluorescence and absorbance) of Gm and its analogs were performed in the presence of SDS, below and above its critical micelle concentration (CMC) (~8 mM), in order to monitor structural changes induced by the interaction with this anionic surfactant (0-15 mM). Interestingly, we found that the analogs interact more strongly with SDS at low concentrations (0.3-6.0 mM) than close to or above its CMC. This suggests that SDS monomers are able to cover the whole peptide, forming large detergent-peptide aggregates. On the other hand, the peptides interact differently with SDS micelles, inserting partially into the micelle core. Among the peptides, Trp in position 1 becomes more motionally-restricted in the presence of SDS, probably because this residue is located at the N-terminal region, which presents higher conformational freedom to interact stronger with SDS molecules. Trp residues in positions 7 and 9, close to and in the region of the turn of the molecule, respectively, induced a more constrained structure and the compounds cannot insert deeper into the micelle core or be completely buried by SDS monomers. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.

  8. Trp53 activity is repressed in radio-adapted cultured murine limb bud cells

    International Nuclear Information System (INIS)

    Vares, Guillaume; Wang, Bing; Tanaka, Kaoru; Shang, Yi; Fujita, Kazuko; Hayata, Isamu; Nenoi, Mitsuru

    2011-01-01

    Understanding the effects of ionizing radiation (IR) at low dose in fetal models is of great importance, because the fetus is considered to be at the most radiosensitive stage of the development and prenatal radiation might influence subsequent development. We previously demonstrated the existence of an adaptive response (AR) in murine fetuses after pre-exposure to low doses of X-rays. Trp53-dependent apoptosis was suggested to be responsible for the teratogenic effects of IR; decreased apoptosis was observed in adapted animals. In this study, in order to investigate the role of Trp53 in AR, we developed a new model of irradiated micromass culture of fetal limb bud cells, which replicated proliferation, differentiation and response to IR in murine embryos. Murine fetuses were exposed to whole-body priming irradiation of 0.3 Gy or 0.5 Gy at embryonic day 11 (E11). Limb bud cells (collected from digital ray areas exhibiting radiation-induced apoptosis) were cultured and exposed to a challenging dose of 4 Gy at E12 equivalent. The levels of Trp53 protein and its phosphorylated form at Ser18 were investigated. Our results suggested that the induction of AR in mouse embryos was correlated with a repression of Trp53 activity. (author)

  9. Specific Function of the Met-Tyr-Trp Adduct Radical and Residues Arg-418 and Asp-137 in the Atypical Catalase Reaction of Catalase-Peroxidase KatG*

    Science.gov (United States)

    Zhao, Xiangbo; Khajo, Abdelahad; Jarrett, Sanchez; Suarez, Javier; Levitsky, Yan; Burger, Richard M.; Jarzecki, Andrzej A.; Magliozzo, Richard S.

    2012-01-01

    Catalase activity of the dual-function heme enzyme catalase-peroxidase (KatG) depends on several structural elements, including a unique adduct formed from covalently linked side chains of three conserved amino acids (Met-255, Tyr-229, and Trp-107, Mycobacterium tuberculosis KatG numbering) (MYW). Mutagenesis, electron paramagnetic resonance, and optical stopped-flow experiments, along with calculations using density functional theory (DFT) methods revealed the basis of the requirement for a radical on the MYW-adduct, for oxyferrous heme, and for conserved residues Arg-418 and Asp-137 in the rapid catalase reaction. The participation of an oxyferrous heme intermediate (dioxyheme) throughout the pH range of catalase activity is suggested from our finding that carbon monoxide inhibits the activity at both acidic and alkaline pH. In the presence of H2O2, the MYW-adduct radical is formed normally in KatG[D137S] but this mutant is defective in forming dioxyheme and lacks catalase activity. KatG[R418L] is also catalase deficient but exhibits normal formation of the adduct radical and dioxyheme. Both mutants exhibit a coincidence between MYW-adduct radical persistence and H2O2 consumption as a function of time, and enhanced subunit oligomerization during turnover, suggesting that the two mutations disrupting catalase turnover allow increased migration of the MYW-adduct radical to protein surface residues. DFT calculations showed that an interaction between the side chain of residue Arg-418 and Tyr-229 in the MYW-adduct radical favors reaction of the radical with the adjacent dioxyheme intermediate present throughout turnover in WT KatG. Release of molecular oxygen and regeneration of resting enzyme are thereby catalyzed in the last step of a proposed catalase reaction. PMID:22918833

  10. Ehrlichia chaffeensis TRP120 Activates Canonical Notch Signaling To Downregulate TLR2/4 Expression and Promote Intracellular Survival

    Directory of Open Access Journals (Sweden)

    Taslima T. Lina

    2016-07-01

    Full Text Available Ehrlichia chaffeensis preferentially targets mononuclear phagocytes and survives through a strategy of subverting innate immune defenses, but the mechanisms are unknown. We have shown E. chaffeensis type 1 secreted tandem repeat protein (TRP effectors are involved in diverse molecular pathogen-host interactions, such as the TRP120 interaction with the Notch receptor-cleaving metalloprotease ADAM17. In the present study, we demonstrate E. chaffeensis, via the TRP120 effector, activates the canonical Notch signaling pathway to promote intracellular survival. We found that nuclear translocation of the transcriptionally active Notch intracellular domain (NICD occurs in response to E. chaffeensis or recombinant TRP120, resulting in upregulation of Notch signaling pathway components and target genes notch1, adam17, hes, and hey. Significant differences in canonical Notch signaling gene expression levels (>40% were observed during early and late stages of infection, indicating activation of the Notch pathway. We linked Notch pathway activation specifically to the TRP120 effector, which directly interacts with the Notch metalloprotease ADAM17. Using pharmacological inhibitors and small interfering RNAs (siRNAs against γ-secretase enzyme, Notch transcription factor complex, Notch1, and ADAM17, we demonstrated that Notch signaling is required for ehrlichial survival. We studied the downstream effects and found that E. chaffeensis TRP120-mediated activation of the Notch pathway causes inhibition of the extracellular signal-regulated kinase 1/2 (ERK1/2 and p38 mitogen-activated protein kinase (MAPK pathways required for PU.1 and subsequent Toll-like receptor 2/4 (TLR2/4 expression. This investigation reveals a novel mechanism whereby E. chaffeensis exploits the Notch pathway to evade the host innate immune response for intracellular survival.

  11. A polycystin-type transient receptor potential (Trp channel that is activated by ATP

    Directory of Open Access Journals (Sweden)

    David Traynor

    2017-02-01

    Full Text Available ATP and ADP are ancient extra-cellular signalling molecules that in Dictyostelium amoebae cause rapid, transient increases in cytosolic calcium due to an influx through the plasma membrane. This response is independent of hetero-trimeric G-proteins, the putative IP3 receptor IplA and all P2X channels. We show, unexpectedly, that it is abolished in mutants of the polycystin-type transient receptor potential channel, TrpP. Responses to the chemoattractants cyclic-AMP and folic acid are unaffected in TrpP mutants. We report that the DIF morphogens, cyclic-di-GMP, GABA, glutamate and adenosine all induce strong cytoplasmic calcium responses, likewise independently of TrpP. Thus, TrpP is dedicated to purinergic signalling. ATP treatment causes cell blebbing within seconds but this does not require TrpP, implicating a separate purinergic receptor. We could detect no effect of ATP on chemotaxis and TrpP mutants grow, chemotax and develop almost normally in standard conditions. No gating ligand is known for the human homologue of TrpP, polycystin-2, which causes polycystic kidney disease. Our results now show that TrpP mediates purinergic signalling in Dictyostelium and is directly or indirectly gated by ATP.

  12. Mutation of I696 and W697 in the TRP box of vanilloid receptor subtype I modulates allosteric channel activation.

    Science.gov (United States)

    Gregorio-Teruel, Lucia; Valente, Pierluigi; González-Ros, José Manuel; Fernández-Ballester, Gregorio; Ferrer-Montiel, Antonio

    2014-03-01

    The transient receptor potential vanilloid receptor subtype I (TRPV1) channel acts as a polymodal sensory receptor gated by chemical and physical stimuli. Like other TRP channels, TRPV1 contains in its C terminus a short, conserved domain called the TRP box, which is necessary for channel gating. Substitution of two TRP box residues-I696 and W697-with Ala markedly affects TRPV1's response to all activating stimuli, which indicates that these two residues play a crucial role in channel gating. We systematically replaced I696 and W697 with 18 native l-amino acids (excluding cysteine) and evaluated the effect on voltage- and capsaicin-dependent gating. Mutation of I696 decreased channel activation by either voltage or capsaicin; furthermore, gating was only observed with substitution of hydrophobic amino acids. Substitution of W697 with any of the 18 amino acids abolished gating in response to depolarization alone, shifting the threshold to unreachable voltages, but not capsaicin-mediated gating. Moreover, vanilloid-activated responses of W697X mutants showed voltage-dependent gating along with a strong voltage-independent component. Analysis of the data using an allosteric model of activation indicates that mutation of I696 and W697 primarily affects the allosteric coupling constants of the ligand and voltage sensors to the channel pore. Together, our findings substantiate the notion that inter- and/or intrasubunit interactions at the level of the TRP box are critical for efficient coupling of stimulus sensing and gate opening. Perturbation of these interactions markedly reduces the efficacy and potency of the activating stimuli. Furthermore, our results identify these interactions as potential sites for pharmacological intervention.

  13. Extracts and compounds active on TRP ion channels from Waldheimia glabra, a ritual medicinal plant from Himalaya.

    Science.gov (United States)

    Giorgi, Annamaria; Bassoli, Angela; Borgonovo, Gigliola; Panseri, Sara; Manzo, Alessandra; Pentimalli, Daniela; Schiano Moriello, Aniello; De Petrocellis, Luciano

    2017-08-15

    Waldheimia glabra (Decne.) Regel is a wild plant from the Himalayan Mountains, commonly known as Smooth Ground Daisy. This plant is traditionally used by local populations in religious rituals (incense) or in traditional herbal medicine to treat skin diseases, headache, joint pain and fever. In literature few data are available on the investigation of this aromatic plant. The present work aims at deepening knowledge about the chemical composition of W. glabra extracts and incense, as well as its activity on TRP ion channels. Extracts and incense of W. glabra were analyzed by using HS-SPME GC/MS, GC/MS and NMR analysis. Tests on the activity of W. glabra extracts and isolated compounds (+)-ludartin 1 and B-ring-homo-tonghaosu 2 on TRP channels were also performed. Some extracts and pure compounds from W. glabra showed an interesting activity in terms of efficacy and potency on rat TRPA1, an ion channel involved in several sensory mechanisms, including pungency, environmental irritation and pain perception. Activity is discussed and compared with that of other known TRPA1 natural agonists with different chemical structures. All compounds showed only a negligible inhibition activity on rat TRPM8 ion channel. Our findings demonstrate that W. glabra is involved in the receptor activation mechanism and therefore represents a new natural product potentially useful in pharmaceutical and agrifood research. Copyright © 2017 Elsevier GmbH. All rights reserved.

  14. Structure-activity relationship studies on a Trp dendrimer with dual activities against HIV and enterovirus A71. Modifications on the amino acid.

    Science.gov (United States)

    Martínez-Gualda, Belén; Sun, Liang; Rivero-Buceta, Eva; Flores, Aida; Quesada, Ernesto; Balzarini, Jan; Noppen, Sam; Liekens, Sandra; Schols, Dominique; Neyts, Johan; Leyssen, Pieter; Mirabelli, Carmen; Camarasa, María-José; San-Félix, Ana

    2017-03-01

    We have recently described a new class of dendrimers with tryptophan (Trp) on the surface that show dual antiviral activities against HIV and EV71 enterovirus. The prototype compound of this family is a pentaerythritol derivative with 12 Trps on the periphery. Here we complete the structure-activity relationship studies of this family to identify key features that might be significant for the antiviral activity. With this aim, novel dendrimers containing different amino acids (aromatic and non-aromatic), tryptamine (a "decarboxylated" analogue of Trp) and N-methyl Trp on the periphery have been prepared. Dendrimer with N-Methyl Trp was the most active against HIV-1 and HIV-2 while dendrimer with tyrosine was endowed with the most potent antiviral activity against EV71. This tyrosine dendrimer proved to inhibit a large panel of EV71 clinical isolates (belonging to different clusters) in the low nanomolar/high picomolar range. In addition, a new synthetic procedure (convergent approach) has been developed for the synthesis of the prototype and some other dendrimers. This convergent approach proved more efficient (higher yields, easier purification) than the divergent approach previously reported. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Phytochemicals from Ruta graveolens Activate TAS2R Bitter Taste Receptors and TRP Channels Involved in Gustation and Nociception

    Directory of Open Access Journals (Sweden)

    Giuseppe Mancuso

    2015-10-01

    Full Text Available Ruta graveolens (rue is a spontaneous plant in the Mediterranean area with a strong aroma and a very intense bitter taste, used in gastronomy and in folk medicine. From the leaves, stems and fruits of rue, we isolated rutin, rutamarin, three furanocoumarins, two quinolinic alkaloids, a dicoumarin and two long chain ketones. Bitter taste and chemesthetic properties have been evaluated by in vitro assays with twenty receptors of the TAS2R family and four TRP ion channels involved in gustation and nociception. Among the alkaloids, skimmianine was active as a specific agonist of T2R14, whereas kokusaginin did not activate any of the tested receptors. The furanocoumarins activates TAS2R10, 14, and 49 with different degrees of selectivity, as well as the TRPA1 somatosensory ion channel. Rutamarin is an agonist of TRPM5 and TRPV1 and a strong antagonist of TRPM8 ion channels.

  16. Phytochemicals from Ruta graveolens Activate TAS2R Bitter Taste Receptors and TRP Channels Involved in Gustation and Nociception.

    Science.gov (United States)

    Mancuso, Giuseppe; Borgonovo, Gigliola; Scaglioni, Leonardo; Bassoli, Angela

    2015-10-16

    Ruta graveolens (rue) is a spontaneous plant in the Mediterranean area with a strong aroma and a very intense bitter taste, used in gastronomy and in folk medicine. From the leaves, stems and fruits of rue, we isolated rutin, rutamarin, three furanocoumarins, two quinolinic alkaloids, a dicoumarin and two long chain ketones. Bitter taste and chemesthetic properties have been evaluated by in vitro assays with twenty receptors of the TAS2R family and four TRP ion channels involved in gustation and nociception. Among the alkaloids, skimmianine was active as a specific agonist of T2R14, whereas kokusaginin did not activate any of the tested receptors. The furanocoumarins activates TAS2R10, 14, and 49 with different degrees of selectivity, as well as the TRPA1 somatosensory ion channel. Rutamarin is an agonist of TRPM5 and TRPV1 and a strong antagonist of TRPM8 ion channels.

  17. Ehrlichia chaffeensis TRP120 Activates Canonical Notch Signaling To Downregulate TLR2/4 Expression and Promote Intracellular Survival

    OpenAIRE

    Lina, Taslima T.; Dunphy, Paige S.; Luo, Tian; McBride, Jere W.

    2016-01-01

    ABSTRACT Ehrlichia chaffeensis preferentially targets mononuclear phagocytes and survives through a strategy of subverting innate immune defenses, but the mechanisms are unknown. We have shown E.?chaffeensis type 1 secreted tandem repeat protein (TRP) effectors are involved in diverse molecular pathogen-host interactions, such as the TRP120 interaction with the Notch receptor-cleaving metalloprotease ADAM17. In the present study, we demonstrate E.?chaffeensis, via the TRP120 effector, activat...

  18. Design and studies of multiple mechanism of anti-Candida activity of a new potent Trp-rich peptide dendrimers.

    Science.gov (United States)

    Zielińska, Paulina; Staniszewska, Monika; Bondaryk, Małgorzata; Koronkiewicz, Mirosława; Urbańczyk-Lipkowska, Zofia

    2015-11-13

    Eight peptide dendrimers were designed as structural mimics of natural cationic amphiphilic peptides with antifungal activity and evaluated for their anti-Candida potential against the wild type strains and mutants. Dendrimer 14 containing four Trp residues and dodecyl tail and a slightly smaller dendrimer 9 decorated with four N-methylated Trp that displayed 100 and 99.7% of growth inhibition at 16 μg/mL respectively, were selected for evaluation against the Candida albicans mutants with disabled biosynthesis of aspartic proteases responsible for host tissue colonization and morphogenesis during biofilm formation (sessile model). Flow cytometry method was employed to detect apoptotic cells with membrane alterations (phosphatidylserine translocation), and differentiation of apoptotic from necrotic cells was also performed. Simultaneous staining of cell surface phosphatidylserine with Annexin-V-Fluorescein and necrotic cells with propidium iodide was conducted. 14 at 16 μg/mL caused C. albicans cells to undergo cellular apoptosis but its increasing concentrations induced necrosis. 14 influenced C. albicans biofilm viability as well as hyphal and cell wall morphology. Confocal microscopy and cell wall staining with calcofluor white revealed that in epithelial model the cell surface structure was perturbed at MIC of peptide dendrimer. It appears that tryptophan or 1-methyltryptophan groups displayed at the surface and positive charges hidden in the dendrimer tree along with hydrocarbon tail located at C-terminus are important for the anti-Candida activity since dendrimers containing tryptamine at C-terminus showed only a moderate activity. Our results suggest that membranolytic dendrimer 14, targeting cellular apoptotic pathway and impairing the cell wall formation in mature biofilm, may be a potential multifunctional antifungal lead compound for the control of C. albicans infections. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  19. Radical scavenging activity of crude polysaccharides from Camellia sinensis

    Directory of Open Access Journals (Sweden)

    Yang Fan

    2011-01-01

    Full Text Available A preparation of crude polysaccharides (TPS was isolated from Camellia sinensis by precipitation and ultrafiltration. TPS1, TPS2, and TPS3 had molecular weights of 240, 21.4, and 2.46 kDa, respectively. The radical scavenging activities of TPS were evaluated by DPPH free radical, hydroxyl radical and superoxide radical scavenging. These results revealed that TPS exhibited strong radical scavenging activity in a concentration-dependent manner. TPS3 with lowest molecular weight showed a higher radical scavenging activity.

  20. Structure-activity relationship of linear peptide Bu-His6-DPhe7-Arg8-Trp9-Gly10-NH2 at the human melanocortin-1 and -4 receptors: DPhe7 and Trp9 substitution.

    Science.gov (United States)

    Danho, Waleed; Swistok, Joseph; Cheung, Adrian Wai-Hing; Kurylko, Grazyna; Franco, Lucia; Chu, Xin-Jie; Chen, Li; Yagaloff, Keith

    2003-02-24

    A series of pentapeptides, based on hMC4R pentapeptide agonist (Bu-His(6)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-NH(2)), was prepared in which either DPhe(7) or Trp(9) residue was systematically substituted. A number of interesting DPhe surrogates (D-Thi, D-3-CF(3)Phe, D-2-Nal and D-3,4-diClPhe) as well as Trp surrogates (2-Nal and Bta) were identified in this study.

  1. Histidine 352 (His352 and tryptophan 355 (Trp355 are essential for flax UGT74S1 glucosylation activity toward secoisolariciresinol.

    Directory of Open Access Journals (Sweden)

    Kaushik Ghose

    Full Text Available Flax secoisolariciresinol diglucoside (SDG lignan is a natural phytoestrogen for which a positive role in metabolic diseases is emerging. Until recently however, much less was known about SDG and its monoglucoside (SMG biosynthesis. Lately, flax UGT74S1 was identified and characterized as an enzyme sequentially glucosylating secoisolariciresinol (SECO into SMG and SDG when expressed in yeast. However, the amino acids critical for UGT74S1 glucosyltransferase activity were unknown. A 3D structural modeling and docking, site-directed mutagenesis of five amino acids in the plant secondary product glycosyltransferase (PSPG motif, and enzyme assays were conducted. UGT74S1 appeared to be structurally similar to the Arabidopsis thaliana UGT72B1 model. The ligand docking predicted Ser357 and Trp355 as binding to the phosphate and hydroxyl groups of UDP-glucose, whereas Cys335, Gln337 and Trp355 were predicted to bind the 7-OH, 2-OCH3 and 17-OCH3 of SECO. Site-directed mutagenesis of Cys335, Gln337, His352, Trp355 and Ser357, and enzyme assays revealed an alteration of these binding sites and a significant reduction of UGT74S1 glucosyltransferase catalytic activity towards SECO and UDP-glucose in all mutants. A complete abolition of UGT74S1 activity was observed when Trp355 was substituted to Ala355 and Gly355 or when changing His352 to Asp352, and an altered metabolite profile was observed in Cys335Ala, Gln337Ala, and Ser357Ala mutants. This study provided for the first time evidence that Trp355 and His352 are critical for UGT74S1's glucosylation activity toward SECO and suggested the possibility for SMG production in vitro.

  2. Impaired 8-Hydroxyguanine Repair Activity of MUTYH Variant p.Arg109Trp Found in a Japanese Patient with Early-Onset Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Kazuya Shinmura

    2014-01-01

    Full Text Available Purpose. The biallelic inactivation of the 8-hydroxyguanine repair gene MUTYH leads to MUTYH-associated polyposis (MAP, which is characterized by colorectal multiple polyps and carcinoma(s. However, only limited information regarding MAP in the Japanese population is presently available. Since early-onset colorectal cancer (CRC is a characteristic of MAP and might be caused by the inactivation of another 8-hydroxyguanine repair gene, OGG1, we investigated whether germline MUTYH and OGG1 mutations are involved in early-onset CRC in Japanese patients. Methods. Thirty-four Japanese patients with early-onset CRC were examined for germline MUTYH and OGG1 mutations using sequencing. Results. Biallelic pathogenic mutations were not found in any of the patients; however, a heterozygous p.Arg19*  MUTYH variant and a heterozygous p.Arg109Trp MUTYH variant were detected in one patient each. The p.Arg19* and p.Arg109Trp corresponded to p.Arg5* and p.Arg81Trp, respectively, in the type 2 nuclear-form protein. The defective DNA repair activity of p.Arg5* is apparent, while that of p.Arg81Trp has been demonstrated using DNA cleavage and supF forward mutation assays. Conclusion. These results suggest that biallelic MUTYH or OGG1 pathogenic mutations are rare in Japanese patients with early-onset CRC; however, the p.Arg19* and p.Arg109Trp MUTYH variants are associated with functional impairments.

  3. Thioredoxin Txnl1/TRP32 Is a Redox-active Cofactor of the 26 S Proteasome

    DEFF Research Database (Denmark)

    Andersen, Katrine M; Klausen, Louise Kjær; Prag, Søren

    2009-01-01

    in the cytoplasm and nucleus. Txnl1 has thioredoxin activity with a redox potential of about -250 mV. Mutant Txnl1 with one active site cysteine replaced by serine formed disulfide bonds to eEF1A1, a substrate-recruiting factor of the 26S proteasome. eEF1A1 is therefore a likely physiological substrate....... In response to knock-down of Txnl1, ubiquitin-protein conjugates were moderately stabilised. Hence, Txnl1 is the first example of a direct connection between protein reduction and proteolysis, two major intracellular protein quality control mechanisms....

  4. Characterization and DPPH Radical Scavenging Activity of Gallic ...

    African Journals Online (AJOL)

    Characterization and DPPH Radical Scavenging Activity of Gallic Acid-Lecithin Complex. C Liu, C Chen, H Ma, E Yuan, Q Li. Abstract. Purpose: To investigate the physicochemical properties and DPPH radical scavenging activity of gallic acid–lecithin complex. Methods: The complex of gallic acid with lecithin was prepared ...

  5. Characterization and DPPH Radical Scavenging Activity of Gallic ...

    African Journals Online (AJOL)

    Antioxidant activity was examined by 1-diphenyl-2-picrylhydrazyl. (DPPH) radical ... antifungal, antiviral, anticancer activities [1-3]. Due to its .... Caesalpinia mimosoides Lamk. Food Chem ... rich extract of Hypericum perforatum L. in vitro. J Agr.

  6. Role of TRP Channels in Dinoflagellate Mechanotransduction.

    Science.gov (United States)

    Lindström, J B; Pierce, N T; Latz, M I

    2017-10-01

    Transient receptor potential (TRP) ion channels are common components of mechanosensing pathways, mainly described in mammals and other multicellular organisms. To gain insight into the evolutionary origins of eukaryotic mechanosensory proteins, we investigated the involvement of TRP channels in mechanosensing in a unicellular eukaryotic protist, the dinoflagellate Lingulodinium polyedra. BLASTP analysis of the protein sequences predicted from the L. polyedra transcriptome revealed six sequences with high similarity to human TRPM2, TRPM8, TRPML2, TRPP1, and TRPP2; and characteristic TRP domains were identified in all sequences. In a phylogenetic tree including all mammalian TRP subfamilies and TRP channel sequences from unicellular and multicellular organisms, the L. polyedra sequences grouped with the TRPM, TPPML, and TRPP clades. In pharmacological experiments, we used the intrinsic bioluminescence of L. polyedra as a reporter of mechanoresponsivity. Capsaicin and RN1734, agonists of mammalian TRPV, and arachidonic acid, an agonist of mammalian TRPV, TRPA, TRPM, and Drosophila TRP, all stimulated bioluminescence in L. polyedra. Mechanical stimulation of bioluminescence, but not capsaicin-stimulated bioluminescence, was inhibited by gadolinium (Gd 3+ ), a general inhibitor of mechanosensitive ion channels, and the phospholipase C (PLC) inhibitor U73122. These pharmacological results are consistent with the involvement of TRP-like channels in mechanosensing by L. polyedra. The TRP channels do not appear to be mechanoreceptors but rather are components of the mechanotransduction signaling pathway and may be activated via a PLC-dependent mechanism. The presence and function of TRP channels in a dinoflagellate emphasize the evolutionary conservation of both the channel structures and their functions.

  7. Repair Activity of trans-Resveratrol toward 2'-Deoxyguanosine Radicals.

    Science.gov (United States)

    Cheng, Xing; An, Ping; Li, Shujin; Zhou, Liping

    2018-04-26

    In the present study, the repair activity of trans-resveratrol toward 2'-deoxyguanosine (dGuo) radicals in polar and nonpolar solvents was studied using density functional theory. The hydrogen transfer/proton coupled electron transfer and single electron transfer (SET) mechanisms between trans-resveratrol and dGuo-radicals were considered. Taking into consideration the molar fraction of neutral trans-resveratrol (ROH) and anionic trans-resveratrol (RO - ), the overall rate constants for repairing dGuo-radicals by trans-resveratrol are 9.94 × 10 8 and 2.01 × 10 9 dm 3 mol -1 s -1 in polar and nonpolar solvents, respectively, and the overall rate constant of repairing cation radical (dGuo •+ ) by trans-resveratrol via an SET mechanism is 7.17 × 10 9 dm 3 mol -1 s -1 . The repair activity of RO - toward dGuo-radicals is better than that of ROH, but the repair activity of ROH toward dGuo •+ is better than that of RO - . Unfortunately, neither ROH nor RO - can repair the 2'-deoxyribose radicals of dGuo. It can therefore be concluded that trans-resveratrol is an effective antioxidant for repairing base radicals of dGuo and dGuo •+ . The study can help us understand the repair activity of trans-resveratrol toward dGuo radicals.

  8. Free Radical Scavenging Activities of Methanol Extract and ...

    African Journals Online (AJOL)

    Michael Horsfall

    fractions were subjected to in vitro antioxidant evaluation using the DPPH free radical scavenging ... The crude extract has IC-50 value for radical scavenging activity of 5μg/mL which was .... effective concentration of the sample that is required.

  9. TRP channels: an overview

    DEFF Research Database (Denmark)

    Pedersen, Stine Falsig; Owsianik, Grzegorz; Nilius, Bernd

    2005-01-01

    The TRP ("transient receptor potential") family of ion channels now comprises more than 30 cation channels, most of which are permeable for Ca2+, and some also for Mg2+. On the basis of sequence homology, the TRP family can be divided in seven main subfamilies: the TRPC ('Canonical') family......, the TRPV ('Vanilloid') family, the TRPM ('Melastatin') family, the TRPP ('Polycystin') family, the TRPML ('Mucolipin') family, the TRPA ('Ankyrin') family, and the TRPN ('NOMPC') family. The cloning and characterization of members of this cation channel family has exploded during recent years, leading...... to a plethora of data on the roles of TRPs in a variety of tissues and species, including mammals, insects, and yeast. The present review summarizes the most pertinent recent evidence regarding the structural and functional properties of TRP channels, focusing on the regulation and physiology of mammalian TRPs....

  10. Antimicrobial and free radical scavenging activities of five ...

    African Journals Online (AJOL)

    Extracts from five indigenous Palestinian medicinal plants including Rosmarinus officinalis, Pisidium guajava, Punica granatum peel, grape seeds and Teucrium polium were investigated for antimicrobial and free radical scavenging activities against eight microorganisms, using well diffusion method. The microorganisms ...

  11. Structure-activity relationship of linear peptide Bu-His-DPhe-Arg-Trp-Gly-NH(2) at the human melanocortin-1 and -4 receptors: arginine substitution.

    Science.gov (United States)

    Cheung, Adrian Wai-Hing; Danho, Waleed; Swistok, Joseph; Qi, Lida; Kurylko, Grazyna; Franco, Lucia; Yagaloff, Keith; Chen, Li

    2002-09-02

    A series of pentapeptides, based on Bu-His(6)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-NH(2) and modified at the Arg(8) position, was prepared and pharmacologically characterized. Peptides containing either cyanoguanidine or acylguanidine, two substantially less basic arginine surrogates, were found to retain the agonist activity of the parent peptide at both hMC1R and hMC4R. This study unequivocally shows that the positive charge of Arg(8) is not essential for efficient interactions of our pentapeptide with both hMC1R and hMC4R.

  12. Characterization of two trpE genes encoding anthranilate synthase α-subunit in Azospirillum brasilense

    International Nuclear Information System (INIS)

    Ge Shimei; Xie Baoen; Chen Sanfeng

    2006-01-01

    The previous report from our laboratory has recently identified a new trpE gene (termed trpE 2 ) which exists independently in Azospirillum brasilense Yu62. In this study, amplification of trpE(G) (termed trpE 1 (G) here) confirmed that there are two copies of trpE gene, one trpE being fused into trpG while the other trpE existed independently. This is First report to suggest that two copies of the trpE gene exist in this bacterium. Comparison of the nucleotide sequence demonstrated that putative leader peptide, terminator, and anti-terminator were found upstream of trpE 1 (G) while these sequence features did not exist in front of trpE 2 . The β-galactosidase activity of an A. brasilense strain carrying a trpE 2 -lacZ fusion remained constant at different tryptophan concentrations, but the β-galactosidase activity of the same strain carrying a trpE 1 (G)-lacZ fusion decreased as the tryptophan concentration increased. These data suggest that the expression of trpE 1 (G) is regulated at the transcriptional level by attenuation while trpE 2 is constantly expressed. The anthranilate synthase assays with trpE 1 (G) - and trpE 2 - mutants demonstrated that TrpE 1 (G) fusion protein is feedback inhibited by tryptophan while TrpE 2 protein is not. We also found that both trpE 1 (G) and trpE 2 gene products were involved in IAA synthesis

  13. Synthesis and Free Radical Scavenging Activity of New Hydroxybenzylidene Hydrazines

    Directory of Open Access Journals (Sweden)

    Frantisek Sersen

    2017-05-01

    Full Text Available Hydroxybenzylidene hydrazines exhibit a wide spectrum of biological activities. Here, we report synthesis and free radical scavenging activity of nine new N-(hydroxybenzylidene-N′-[2,6-dinitro-4-(trifluoromethyl]phenylhydrazines. The chemical structures of these compounds were confirmed by 1H-NMR, 13C-NMR, 19F-NMR, IR spectroscopy, LC-MS, and elemental analysis. The prepared compounds were tested for their activity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH, galvinoxyl radical (GOR, and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS radicals. The free radical scavenging activity expressed as SC50 values of these compounds varied in a wide range, from a strong to no radical scavenging effect. The most effective radical scavengers were hydroxybenzylidene hydrazines containing three hydroxyl groups in the benzylidene part of their molecules. The prepared compounds were also tested for their activity to inhibit photosynthetic electron transport in spinach chloroplasts. IC50 values of these compounds varied in wide range, from an intermediate to no inhibitory effect.

  14. Synthesis and Free Radical Scavenging Activity of New Hydroxybenzylidene Hydrazines.

    Science.gov (United States)

    Sersen, Frantisek; Gregan, Fridrich; Kotora, Peter; Kmetova, Jarmila; Filo, Juraj; Loos, Dusan; Gregan, Juraj

    2017-05-29

    Hydroxybenzylidene hydrazines exhibit a wide spectrum of biological activities. Here, we report synthesis and free radical scavenging activity of nine new N-(hydroxybenzylidene)-N'-[2,6-dinitro-4-(trifluoromethyl)]phenylhydrazines. The chemical structures of these compounds were confirmed by 1H-NMR, 13C-NMR, 19F-NMR, IR spectroscopy, LC-MS, and elemental analysis. The prepared compounds were tested for their activity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH), galvinoxyl radical (GOR), and 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulphonic acid (ABTS) radicals. The free radical scavenging activity expressed as SC50 values of these compounds varied in a wide range, from a strong to no radical scavenging effect. The most effective radical scavengers were hydroxybenzylidene hydrazines containing three hydroxyl groups in the benzylidene part of their molecules. The prepared compounds were also tested for their activity to inhibit photosynthetic electron transport in spinach chloroplasts. IC50 values of these compounds varied in wide range, from an intermediate to no inhibitory effect.

  15. Bergenin Content and Free Radical Scavenging Activity of Bergenia Extracts. .

    Science.gov (United States)

    Hendrychová, Helena; Martin, Jan; Tůmová, Lenka; Kočevar-Glavač, Nina

    2015-07-01

    Our research was focused on the evaluation of bergenin content and free radical scavenging activity of extracts prepared from three different species of Bergenia - B. crassifolia (L.) Fritsch., B. ciliata (Haw.) Sternb. and B. x ornata Stein. collected during different seasons. Using an HPLC method, the highest total amount of bergenin was revealed in the leaves of B. x ornata and B. crassifolia (4.9 - 5.1 mg x g(-1)). Free radical scavenging power was determined by two methods--FRAP and NADH. The best free radical scavengers were B. crassifolia (FRAP: 6.7 - 15.9 mg GAE. 100g(-1); NADH: 20.3 - 50.9%) and B. ornata (FRAP: 13.7 - 15.2 mg GAE. 100g(-1); NADH: 29.3 - 31.1%). The lowest content of bergenin and the weakest radical scavenger was B. ciliata (bergenin: 3.1 mg x g(-1); FRAP: 5.5 - 11.0 mg GAE.100g(-1); NADH: 23.2 - 25.6%). The presence of a large percentage of bergenin is responsible for the radical scavenging activity, as shown by the results from the FRAP and NADH assays. Significant, positive correlation was found between bergenin content and radical scavenging activity in both methods.

  16. Free radical scavenging activity of Eagle tea and their flavonoids

    Directory of Open Access Journals (Sweden)

    Qiong Meng

    2012-06-01

    Full Text Available In this study, an online HPLC-DAD-MS coupled with 2,2′-azinobis (3-ethylbenzthiazoline-6-sulfonic acid diammonium salt (ABTS assay was employed for evaluating free radical scavenging activity of Eagle tea and their active components. Twenty-three chromatographic peaks were detected, and nineteen components had free radical scavenging activity. Among them, eight compounds were identified as flavonoids (hyperin, isoquercitrin, quercitrin, quercetin, kaempferol, catechins, chlorogenic acid and epicatechin based on MS data and standard chromatographic characters.

  17. Post-Translational Modifications of TRP Channels

    Directory of Open Access Journals (Sweden)

    Olaf Voolstra

    2014-04-01

    Full Text Available Transient receptor potential (TRP channels constitute an ancient family of cation channels that have been found in many eukaryotic organisms from yeast to human. TRP channels exert a multitude of physiological functions ranging from Ca2+ homeostasis in the kidney to pain reception and vision. These channels are activated by a wide range of stimuli and undergo covalent post-translational modifications that affect and modulate their subcellular targeting, their biophysical properties, or channel gating. These modifications include N-linked glycosylation, protein phosphorylation, and covalent attachment of chemicals that reversibly bind to specific cysteine residues. The latter modification represents an unusual activation mechanism of ligand-gated ion channels that is in contrast to the lock-and-key paradigm of receptor activation by its agonists. In this review, we summarize the post-translational modifications identified on TRP channels and, when available, explain their physiological role.

  18. Stimulation of Drosophila TrpL by capacitative Ca2+ entry.

    OpenAIRE

    Estacion, M; Sinkins, W G; Schilling, W P

    1999-01-01

    Trp-like protein (TrpL, where Trp is transient receptor-potential protein) of Drosophila, a non-selective cation channel activated in photoreceptor cells by a phospholipase C-dependent mechanism, is thought to be a prototypical receptor-activated channel. Our previous studies showed that TrpL channels are not activated by depletion of internal Ca2+ stores when expressed in Sf9 cells. Using fura-2 to measure cation influx via TrpL, and cell-attached patch recordings to monitor TrpL single-chan...

  19. Bureaucratic Activism and Radical School Change in Tamil Nadu, India

    Science.gov (United States)

    Niesz, Tricia; Krishnamurthy, Ramchandar

    2013-01-01

    In 2007, Activity Based Learning (ABL), a child-centered, activity-based method of pedagogical practice, transformed classrooms in all of the over 37,000 primary-level government schools in Tamil Nadu, India. The large scale, rapid pace, and radical nature of educational change sets the ABL initiative apart from most school reform efforts.…

  20. In vitro free radical scavenging activity of platinum nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Aki; Kajita, Masashi; Kim, Juewon; Kanayama, Atsuhiro; Miyamoto, Yusei [Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Bioscience Building 402, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8562 (Japan); Takahashi, Kyoko; Mashino, Tadahiko, E-mail: yusei74@k.u-tokyo.ac.j [Department of Pharmaceutical Sciences, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato, Tokyo 105-8512 (Japan)

    2009-11-11

    A polyacrylic acid (PAA)-protected platinum nanoparticle species (PAA-Pt) was prepared by alcohol reduction of hexachloroplatinate. The PAA-Pt nanoparticles were well dispersed and homogeneous in size with an average diameter of 2.0 {+-} 0.4 nm (n = 200). We used electron spin resonance to quantify the residual peroxyl radical AOO. generated from 2,2-azobis (2-aminopropane) dihydrochloride (AAPH) by thermal decomposition in the presence of O{sub 2} and a spectrophotometric method to quantify the residual 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. PAA-Pt scavenged these two radicals in a dose-dependent manner. Platinum was the functional component. PAA-Pt reduced the rate of oxygen consumption required for linoleic acid peroxidation initiated by AOO. generated from AAPH, indicating inhibition of the propagation of linolate peroxidation. A thiobarbituric acid test also revealed dose-dependent inhibition of the linolate peroxidation by PAA-Pt. Fifty micromolar platinum, as PAA-Pt, completely quenched 250 {mu}M DPPH radical for 5 min. Even when twice diluted in half, the PAA-Pt still quenched 100% of the 250 {mu}M DPPH radical. The scavenging activity of PAA-Pt is durable. These observations suggest that PAA-Pt is an efficient scavenger of free radicals.

  1. Structure-activity relationships of the melanocortin tetrapeptide Ac-His-DPhe-Arg-Trp-NH(2) at the mouse melanocortin receptors: part 2 modifications at the Phe position.

    Science.gov (United States)

    Holder, Jerry Ryan; Bauzo, Rayna M; Xiang, Zhimin; Haskell-Luevano, Carrie

    2002-07-04

    The melanocortin pathway is an important participant in skin pigmentation, steroidogenesis, obesity, energy homeostasis and exocrine gland function. The centrally located melanocortin-3 and melanocortin-4 receptors (MC3R, MC4R) are involved in the metabolic and food intake aspects of energy homeostasis and are stimulated by melanocortin agonists such as alpha-melanocyte stimulation hormone (alpha-MSH). The melanocortin agonists contain the putative message sequence "His-Phe-Arg-Trp," and it has been well-documented that inversion of chirality of the Phe to DPhe results in a dramatic increase in melanocortin receptor potency. Herein, we report a tetrapeptide library, based upon the template Ac-His-DPhe-Arg-Trp-NH(2), consisting of 26 members that have been modified at the DPhe(7) position (alpha-MSH numbering) and pharmacologically characterized for agonist and antagonist activity at the mouse melanocortin receptors MC1R, MC3R, MC4R, and MC5R. The most notable results of this study include the identification of the tetrapeptide Ac-His-(pI)DPhe-Arg-Trp-NH(2) that is a full nanomolar agonist at the mMC1 and mMC5 receptors, a mMC3R partial agonist with potent antagonist activity (pA(2) = 7.25, K(i) = 56 nM) and, but unexpectedly, is a potent agonist at the mMC4R (EC(50) = 25 nM). This ligand possesses novel melanocortin receptor pharmacology, as compared to previously reported peptides, and is potentially useful for in vivo studies to differentiate MC3R vs MC4R physiological roles in animal models, such as primates, where "knockout" animals are not viable options. The DNal(2') substitution for DPhe resulted in a mMC3R partial agonist with antagonist activity (pA(2) = 6.5, K(i) = 295 nM) and a mMC4R (pA(2) = 7.8, K(i) = 17 nM) antagonist possessing 60- and 425-fold decreased potency, respectively, as compared with SHU9119 at these receptors. Examination of this DNal(2')-containing tetrapeptide at the F254S and F259S mutant mMC4Rs resulted in agonist activity of this m

  2. Short Communication Radical Scavenging Activity and Preliminary ...

    African Journals Online (AJOL)

    Bheema

    It is distributed in some regions of Ethiopia such as Tigray, Gondar, Gojam,. Kefa and Shewa ..... Diterpenoids and flavonoids from the fruits of Vitex agnus-castus and antioxidant activity of the fruit extracts and their constituents. Phytotherapy ...

  3. Role of TRP channels in the cardiovascular system.

    Science.gov (United States)

    Yue, Zhichao; Xie, Jia; Yu, Albert S; Stock, Jonathan; Du, Jianyang; Yue, Lixia

    2015-02-01

    The transient receptor potential (TRP) superfamily consists of a large number of nonselective cation channels with variable degree of Ca(2+)-permeability. The 28 mammalian TRP channel proteins can be grouped into six subfamilies: canonical, vanilloid, melastatin, ankyrin, polycystic, and mucolipin TRPs. The majority of these TRP channels are expressed in different cell types including both excitable and nonexcitable cells of the cardiovascular system. Unlike voltage-gated ion channels, TRP channels do not have a typical voltage sensor, but instead can sense a variety of other stimuli including pressure, shear stress, mechanical stretch, oxidative stress, lipid environment alterations, hypertrophic signals, and inflammation products. By integrating multiple stimuli and transducing their activity to downstream cellular signal pathways via Ca(2+) entry and/or membrane depolarization, TRP channels play an essential role in regulating fundamental cell functions such as contraction, relaxation, proliferation, differentiation, and cell death. With the use of targeted deletion and transgenic mouse models, recent studies have revealed that TRP channels are involved in numerous cellular functions and play an important role in the pathophysiology of many diseases in the cardiovascular system. Moreover, several TRP channels are involved in inherited diseases of the cardiovascular system. This review presents an overview of current knowledge concerning the physiological functions of TRP channels in the cardiovascular system and their contributions to cardiovascular diseases. Ultimately, TRP channels may become potential therapeutic targets for cardiovascular diseases. Copyright © 2015 the American Physiological Society.

  4. Structure-activity relationships of the melanocortin tetrapeptide Ac-His-DPhe-Arg-Trp-NH2 at the mouse melanocortin receptors. Part 3: modifications at the Arg position.

    Science.gov (United States)

    Holder, Jerry Ryan; Xiang, Zhimin; Bauzo, Rayna M; Haskell-Luevano, Carrie

    2003-01-01

    The melanocortin pathway is involved in the regulation of several physiological functions including skin pigmentation, steroidogenesis, obesity, energy homeostasis, and exocrine gland function. This melanocortin pathway consists of five known G-protein coupled receptors, endogenous agonists derived from the proopiomelanocortin (POMC) gene transcript, the endogenous antagonists Agouti and the Agouti-related protein (AGRP) and signals through the intracellular cAMP signal transduction pathway. The melanocortin-3 receptor (MC3R) and melanocortin-4 receptor (MC4R) located in the brain are implicated as participating in the metabolic and food intake aspects of energy homeostasis and are stimulated by melanocortin agonists such as alpha-melanocyte stimulation hormone (alpha-MSH). All the endogenous (POMC-derived) melanocortin agonists contain the putative message sequence "His-Phe-Arg-Trp." Herein, we report 12 tetrapeptides, based upon the template Ac-His(6)-DPhe(7)-Arg(8)-Trp(9)-NH(2) (alpha-MSH numbering) that have been modified at the Arg(8) position by neutral, basic, or acidic amino acid side chains. These peptides have been pharmacologically characterized for agonist activity at the mouse melanocortin receptors MC1R, MC3R, MC4R, and MC5R. The most notable results of this study include the observation that removal of the guanidinyl side chain moiety results in decreased melanocortin receptor potency, but that this Arg(8) side chain is not critical for melanocortin receptor agonist activity. Additionally, incorporation of the homoArg(8) residue results in 56-fold MC4R versus MC3R selectivity, and the Orn(8) residue results in 123-fold MC4R versus MC5R and 63-fold MC5R versus MC3R selectivity. Copyright 2002 Elsevier Science Inc.

  5. Free radical scavenging activity and phenolic contents of ...

    African Journals Online (AJOL)

    Anthocleista djalonensis extract is widely used in Nigerian folk medicine to treat conditions whose pathogenesis implicate oxidative stress, such as diabetes and hepatitis. However, little is known of the mechanism underlying these activities. In this study, the free radical scavenging potential of a methanol extract of A.

  6. Hydroxyl radical scavenging activity of peptide from sea cucumber ...

    African Journals Online (AJOL)

    enzyme complex, sea cucumber protein hydrolysis was carried out to obtain hydrolysates that have hydroxyl-radical-scavenging activity (HRSA). The hydrolytic process was monitored by HRSA and conditions for this process were optimized as follows: pH 6.5, temperature 35°C, 12 mg enzyme complex in a reaction solution ...

  7. Free Radical Scavenging Activity of Scoparia dulcis Extract.

    Science.gov (United States)

    Babincová, M.; Sourivong, P.

    2001-01-01

    We studied the scavenging capabilities of an extract of Scoparia dulcis (a cosmopolitan weed widespread in Laos and Vietnam) for 1-diphenyl-2-picrylhydrazyl and measured hemoglobin-catalyzed linoleic acid peroxidation with an oxygen electrode. Our results demonstrated strong antioxidant activity corresponding to mitigation of the generation of hydroxyl radicals, a possible rationale for the observed therapeutic effects of this weed.

  8. Antioxidant and free radical scavenging activities of plant extracts ...

    African Journals Online (AJOL)

    Twenty-two species of medicinal plants collected in the Mexican state of Morelos were selected to evaluate their free radical scavenging and antioxidant activities. The extracts from the aerial parts of the plants were obtained using hexane, acetone and methanol (66 extracts). The initial qualitative screening of antioxidants ...

  9. Free radical scavenging and cytotoxic activity of five commercial ...

    African Journals Online (AJOL)

    Polygonum cuspidatum), and pomegranate (Punica granatum). It shows radical scavenging activity in the following order, according to their median effective concentration (EC

  10. Temperature Activated Diffusion of Radicals through Ion Implanted Polymers

    DEFF Research Database (Denmark)

    Wakelin, Edgar A.; Davies, Michael J.; Bilek, Marcela M. M.

    2015-01-01

    Plasma immersion ion implantation (PIII) is a promising technique for immobilizing biomolecules on the surface of polymers. Radicals generated in a subsurface layer by PIII treatment diffuse throughout the substrate, forming covalent bonds to molecules when they reach the surface. Understanding...... to the surface. The model makes useful predictions for the lifetime over which the surface is sufficiently active to covalently immobilize biomolecules and it can be used to determine radical fluence during biomolecule incubation for a range of storage and incubation temperatures so facilitating selection...

  11. Structure-activity relationship of cyclic peptide penta-c[Asp-His(6)-DPhe(7)-Arg(8)-Trp(9)-Lys]-NH(2) at the human melanocortin-1 and -4 receptors: His(6) substitution.

    Science.gov (United States)

    Cheung, Adrian Wai-Hing; Danho, Waleed; Swistok, Joseph; Qi, Lida; Kurylko, Grazyna; Rowan, Karen; Yeon, Mitch; Franco, Lucia; Chu, Xin-Jie; Chen, Li; Yagaloff, Keith

    2003-04-07

    A series of MT-II related cyclic peptides, based on potent but non-selective hMC4R agonist (Penta-c[Asp-His(6)-DPhe(7)-Arg(8)-Trp(9)-Lys]-NH(2)) was prepared in which His(6) residue was systematically substituted. Two of the most interesting peptides identified in this study are Penta-c[Asp-5-ClAtc-DPhe-Arg-Trp-Lys]-NH(2) and Penta-c[Asp-5-ClAtc-DPhe-Cit-Trp-Lys]-NH(2) which are potent hMC4R agonists and are either inactive or weak partial agonists (not tested for their antagonist activities) in hMC1R, hMC3R and hMC5R agonist assays.

  12. Transnational Islamic activism and radicalization : patterns, trends, and prognosticators.

    Energy Technology Data Exchange (ETDEWEB)

    Colbaugh, Richard; Engi, Dennis; LaViolette, Randall A.; Spomer, Judith E.

    2010-06-01

    The research described in this report developed the theoretical and conceptual framework for understanding, recognizing, and anticipating the origins, dynamic mechanisms, perceptions, and social structures of Islamic social reform movements in the Muslim homeland and in diaspora communities. This research has revealed valuable insights into the dynamic mechanisms associated with reform movements and, as such, offers the potential to provide indications and warnings of impending violence. This study produced the following significant findings: (1) A framework for understanding Islamic radicalization in the context of Social Movement Theory was developed and implemented. This framework provides a causal structure for the interrelationships among the myriad features of a social movement. (2) The degree to which movement-related activity shows early diffusion across multiple social contexts is a powerful distinguisher of successful and unsuccessful social movements. Indeed, this measurable appears to have significantly more predictive power than volume of such activity and also more power than various system intrinsics. (3) Significant social movements can occur only if both the intra-context 'infectivity' of the movement exceeds a certain threshold and the inter-context interactions associated with the movement occur with a frequency that is larger than another threshold. Note that this is reminiscent of, and significantly extends, well-known results for epidemic thresholds in disease propagation models. (4) More in-depth content analysis of blogs through the lens of Argumentation Theory has the potential to reveal new insights into radicalization in the context of Social Movement Theory. This connection has the potential to be of value from two important perspectives - first, this connection has the potential to provide more in depth insights into the forces underlying the emergence of radical behavior and second, this connection may provide insights into

  13. In vitro free radical scavenging activity of Ixora coccinea L

    Directory of Open Access Journals (Sweden)

    Moni Rani Saha

    2008-06-01

    Full Text Available Antioxidant activity of the methanol extract of Ixora coccinea L. was determined by DPPH free radical scavenging assay, reducing power and total antioxidant capacity using phosphomolybdenum method. Preliminary phytochemical screening revealed that the extract of the flower of I. coccinea possesses flavonoids, steroids and tannin materials. The extract showed significant activities in all antioxidant assays compared to the standard antioxidant in a dose dependent manner and remarkable activities to scavenge reactive oxygen species (ROS may be attributed to the high amount of hydrophilic phenolics. In DPPH radical scavenging assay the IC50 value of the extract was found to be 100.53 μg/mL while ascorbic acid had the IC50 value 58.92 μg/mL. Moreover, I. coccinea extract showed strong reducing power and total antioxidant capacity.

  14. TRP channels in kidney disease.

    NARCIS (Netherlands)

    Hsu, Y.J.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2007-01-01

    Mammalian TRP channel proteins form six-transmembrane cation-permeable channels that may be grouped into six subfamilies on the basis of amino acid sequence homology (TRPC, TRPV, TRPM, TRPA, TRPP, and TRPML). Recent studies of TRP channels indicate that they are involved in numerous fundamental cell

  15. The transient receptor potential, TRP4, cation channel is a novel member of the family of calmodulin binding proteins.

    OpenAIRE

    Trost, C; Bergs, C; Himmerkus, N; Flockerzi, V

    2001-01-01

    The mammalian gene products, transient receptor potential (trp)1 to trp7, are related to the Drosophila TRP and TRP-like ion channels, and are candidate proteins underlying agonist-activated Ca(2+)-permeable ion channels. Recently, the TRP4 protein has been shown to be part of native store-operated Ca(2+)-permeable channels. These channels, most likely, are composed of other proteins in addition to TRP4. In the present paper we report the direct interaction of TRP4 and calmodulin (CaM) by: (1...

  16. Measurement of antioxidant activity with trifluoperazine dihydrochloride radical cation

    Directory of Open Access Journals (Sweden)

    M.N. Asghar

    2008-06-01

    Full Text Available A novel, rapid and cost-effective trifluoperazine dihydrochloride (TFPH decolorization assay is described for the screening of antioxidant activity. A chromogenic reaction between TFPH and potassium persulfate at low pH produces an orange-red radical cation with maximum absorption at 502 nm in its first-order derivative spectrum. TFPH was dissolved in distilled water to give a 100 mM solution. The TFPH radical cation solution was made by reacting 0.5 mL of the solution with K2S2O8 (final concentration: 0.1 mM and diluting to 100 mL with 4 M H2SO4 solution. A linear inhibition of color production was observed with linearly increasing amounts of antioxidants, with correlation coefficients (R² ranging from 0.999 to 0.983. The antioxidant capacity of standard solutions of an antioxidant was evaluated by comparing with the inhibition curve using Trolox as the standard. Comparison of antioxidant capacity determined with this newly developed TFPH assay and with the well-known 2,2'-azinobis-[3-ethylbenzthiazoline-6-sulfonic acid] (ABTS-persulfate decolorization assay indicated the efficacy and sensitivity of the procedure. The proposed assay is less expensive (costs about US$4 per 100 assays and requires only 20 min for preparation of radical cation solution in comparison with ABTS assay, in which almost 12-16 h are required for preparation of a stable ABTS radical cation solution. The present assay has the advantage over ABTS assay that it can be used to measure the antioxidant activity of the samples, which are naturally found at a pH as low as 1, because the radical cation itself has been stabilized at low pH.

  17. Structure-activity relationship of linear peptide Bu-His-DPhe-Arg-Trp-Gly-NH(2) at the human melanocortin-1 and -4 receptors: histidine substitution.

    Science.gov (United States)

    Cheung, Adrian Wai-Hing; Danho, Waleed; Swistok, Joseph; Qi, Lida; Kurylko, Grazyna; Rowan, Karen; Yeon, Mitch; Franco, Lucia; Chu, Xin-Jie; Chen, Li; Yagaloff, Keith

    2003-01-06

    Systematic substitution of His(6) residue using non-selective hMC4R pentapeptide agonist (Bu-His(6)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-NH(2)) as the template led to the identification of Bu-Atc(6)(2-aminotetraline-2-carboxylic acid)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-NH(2) which showed moderate selectivity towards hMC4R over hMC1R. Further SAR studies resulted in the discovery of Penta-5-BrAtc(6)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-NH(2) and Penta-5-Me(2)NAtc(6)-DPhe(7)-Arg(8)-Trp(9)-Gly(10)-NH(2) which are potent hMC4R agonists and are inactive in hMC1R, hMC3R and hMC5R agonist assays.

  18. "TRP inflammation" relationship in cardiovascular system.

    Science.gov (United States)

    Numata, Tomohiro; Takahashi, Kiriko; Inoue, Ryuji

    2016-05-01

    Despite considerable advances in the research and treatment, the precise relationship between inflammation and cardiovascular (CV) disease remains incompletely understood. Therefore, understanding the immunoinflammatory processes underlying the initiation, progression, and exacerbation of many cardiovascular diseases is of prime importance. The innate immune system has an ancient origin and is well conserved across species. Its activation occurs in response to pathogens or tissue injury. Recent studies suggest that altered ionic balance, and production of noxious gaseous mediators link to immune and inflammatory responses with altered ion channel expression and function. Among plausible candidates for this are transient receptor potential (TRP) channels that function as polymodal sensors and scaffolding proteins involved in many physiological and pathological processes. In this review, we will first focus on the relevance of TRP channel to both exogenous and endogenous factors related to innate immune response and transcription factors related to sustained inflammatory status. The emerging role of inflammasome to regulate innate immunity and its possible connection to TRP channels will also be discussed. Secondly, we will discuss about the linkage of TRP channels to inflammatory CV diseases, from a viewpoint of inflammation in a general sense which is not restricted to the innate immunity. These knowledge may serve to provide new insights into the pathogenesis of various inflammatory CV diseases and their novel therapeutic strategies.

  19. Iodine-catalyzed diazo activation to access radical reactivity.

    Science.gov (United States)

    Li, Pan; Zhao, Jingjing; Shi, Lijun; Wang, Jin; Shi, Xiaodong; Li, Fuwei

    2018-05-17

    Transition-metal-catalyzed diazo activation is a classical way to generate metal carbene, which are valuable intermediates in synthetic organic chemistry. An alternative iodine-catalyzed diazo activation is disclosed herein under either photo-initiated or thermal-initiated conditions, which represents an approach to enable carbene radical reactivity. This metal-free diazo activation strategy were successfully applied into olefin cyclopropanation and epoxidation, and applying this method to pyrrole synthesis under thermal-initiated conditions further demonstrates the unique reactivity using this method over typical metal-catalyzed conditions.

  20. Copper-induced activation of TRP channels promotes extracellular calcium entry and activation of CaMs and CDPKs leading to copper entry and membrane depolarization in Ulva compressa

    Directory of Open Access Journals (Sweden)

    Melissa eGómez

    2015-03-01

    Full Text Available In order to identify channels involved in membrane depolarization, Ulva compressa was incubated with agonists of TRP channels C5, A1 and V1 and the level of intracellular calcium was detected. Agonists of TRPC5, A1 and V1 induced increases in intracellular calcium at 4, 9 and 12 min of exposure, respectively, and antagonists of TRPC5, A1 and V1 corresponding to SKF-96365 (SKF, HC-030031 (HC and capsazepin (CPZ, respectively, inhibited calcium increases indicating that functional TRPs exist in U. compressa. In addition, copper excess induced increases in intracellular calcium at 4, 9 and 12 min which were inhibited by SKF, HC and CPZ, respectively, indicating that copper activate TRPC5, A1 and V1 channels. Moreover, copper-induced calcium increases were inhibited by EGTA, a non-permeable calcium chelating agent, but not by thapsigargin, an inhibitor of endoplasmic reticulum (ER calcium ATPase, indicating that activation of TRPs leads to extracellular calcium entry. Furthermore, copper-induced calcium increases were not inhibited by W-7, an inhibitor of CaMs, and staurosporine, an inhibitor of CDPKs, indicating that extracellular calcium entry did not require CaMs and CDPKs activation. In addition, copper induced membrane depolarization events at 4, 8 and 11 min and these events were inhibited by SKF, HC, CPZ and bathocuproine, a specific copper chelating agent, indicating copper entry through TRP channels leading to membrane depolarization. Moreover, membrane depolarization events were inhibited by W-7 and staurosporine, indicating that CaMs and CDPKs are required in order to activate TRPs to allow copper entry. Thus, light-dependent copper-induced activation TRPC5, A1 and V1 promotes extracellular calcium entry leading to activation of CaMs and CDPKs which, in turn, promotes copper entry through these TRP channels leading to membrane depolarization.

  1. Structure-activity relationships of the melanocortin tetrapeptide Ac-His-DPhe-Arg-Trp-NH(2) at the mouse melanocortin receptors. 1. Modifications at the His position.

    Science.gov (United States)

    Holder, Jerry Ryan; Bauzo, Rayna M; Xiang, Zhimin; Haskell-Luevano, Carrie

    2002-06-20

    The melanocortin pathway is an important participant in obesity and energy homeostasis. The centrally located melanocortin-3 and melanocortin-4 receptors (MC3R, MC4R) are involved in the metabolic and food intake aspects of energy homeostasis and are stimulated by melanocortin agonists such as alpha-melanocyte stimulation hormone (alpha-MSH). The melanocortin agonists contain the putative message sequence "His-Phe-Arg-Trp", and it has been well documented that inversion of chirality of the Phe to DPhe results in a dramatic increase in melanocortin receptor potency. Herein, we report a tetrapeptide library based on the template Ac-His-DPhe-Arg-Trp-NH(2), consisting of 17 members that have been modified at the His(6) position (alpha-MSH numbering) and pharmacologically characterized for agonist activity at the mouse melanocortin receptors MC1R, MC3R, MC4R, and MC5R. These studies provide further experimental evidence that the His(6) position can determine MC4R versus MC3R agonist selectivity and that chemically nonreactive side chains may be substituted for the imidazole ring (generally needs to be side chain protected in synthetic schemes) in the design of MC4R-selective, small-molecule, non-peptide agonists. Specifically, the tetrapeptide containing the amino-2-naphthylcarboxylic acid (Anc) amino acid at the His position resulted in a potent agonist at the mMC4R (EC(50) = 21 nM), was a weak mMC3R micromolar antagonist (pA(2) = 5.6, K(i) = 2.5 microM), and possessed >4700-fold agonist selectivity for the MC4R versus the MC3R. Substitution of the His(6) amino acid in the tetrapeptide template by the Phe, Anc, 3-(2-thienyl)alanine (2Thi), and 3-(4-pyridinyl)alanine (4-Pal) resulted in equipotency or only up to a 7-fold decrease in potency, compared to the His(6)-containing tetrapeptide at the mMC4R, demonstrating that these amino acid side chains may be substituted for the imidazole in the design of MC4R-selective non-peptide molecules.

  2. Structure-activity relationships of the unique and potent agouti-related protein (AGRP)-melanocortin chimeric Tyr-c[beta-Asp-His-DPhe-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH2 peptide template.

    Science.gov (United States)

    Wilczynski, Andrzej; Wilson, Krista R; Scott, Joseph W; Edison, Arthur S; Haskell-Luevano, Carrie

    2005-04-21

    The melanocortin receptor system consists of endogenous agonists, antagonists, G-protein coupled receptors, and auxiliary proteins that are involved in the regulation of complex physiological functions such as energy and weight homeostasis, feeding behavior, inflammation, sexual function, pigmentation, and exocrine gland function. Herein, we report the structure-activity relationship (SAR) of a new chimeric hAGRP-melanocortin agonist peptide template Tyr-c[beta-Asp-His-DPhe-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) that was characterized using amino acids previously reported in other melanocortin agonist templates. Twenty peptides were examined in this study, and six peptides were selected for (1)H NMR and computer-assisted molecular modeling structural analysis. The most notable results include the identification that modification of the chimeric template at the His position with Pro and Phe resulted in ligands that were nM mouse melanocortin-3 receptor (mMC3R) antagonists and nM mouse melanocortin-4 receptor (mMC4R) agonists. The peptides Tyr-c[beta-Asp-His-DPhe-Ala-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) and Tyr-c[beta-Asp-His-DNal(1')-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) resulted in 730- and 560-fold, respectively, mMC4R versus mMC3R selective agonists that also possessed nM agonist potency at the mMC1R and mMC5R. Structural studies identified a reverse turn occurring in the His-DPhe-Arg-Trp domain, with subtle differences observed that may account for the differences in melanocortin receptor pharmacology. Specifically, a gamma-turn secondary structure involving the DPhe(4) in the central position of the Tyr-c[beta-Asp-Phe-DPhe-Arg-Trp-Asn-Ala-Phe-Dpr]-Tyr-NH(2) peptide may differentiate the mixed mMC3R antagonist and mMC4R agonist pharmacology.

  3. TRP Channels in Human Prostate

    Directory of Open Access Journals (Sweden)

    Carl Van Haute

    2010-01-01

    Full Text Available This review gives an overview of morphological and functional characteristics in the human prostate. It will focus on the current knowledge about transient receptor potential (TRP channels expressed in the human prostate, and their putative role in normal physiology and prostate carcinogenesis. Controversial data regarding the expression pattern and the potential impact of TRP channels in prostate function, and their involvement in prostate cancer and other prostate diseases, will be discussed.

  4. Generation of radicals and antimalarial activity of dispiro-1,2,4-trioxolanes

    Science.gov (United States)

    Denisov, E. T.; Denisova, T. G.

    2013-01-01

    The kinetic schemes of the intramolecular oxidation of radicals generated from substituted dispiro-1,2,4-trioxolanes (seven compounds) in the presence of Fe2+ and oxygen were built. Each radical reaction was defined in terms of enthalpy, activation energy, and rate constant. The kinetic characteristics were calculated by the intersecting parabolas method. The competition between the radical reactions was considered. The entry of radicals generated by each compound into the volume was calculated. High antimalarial activity was found for 1,2,4-trioxolanes, which generated hydroxyl radicals. The structural features of trioxolanes responsible for the generation of hydroxyl radicals were determined.

  5. The Rise of Radicals in Bioinorganic Chemistry.

    Science.gov (United States)

    Gray, Harry B; Winkler, Jay R

    2016-10-01

    Prior to 1950, the consensus was that biological transformations occurred in two-electron steps, thereby avoiding the generation of free radicals. Dramatic advances in spectroscopy, biochemistry, and molecular biology have led to the realization that protein-based radicals participate in a vast array of vital biological mechanisms. Redox processes involving high-potential intermediates formed in reactions with O 2 are particularly susceptible to radical formation. Clusters of tyrosine (Tyr) and tryptophan (Trp) residues have been found in many O 2 -reactive enzymes, raising the possibility that they play an antioxidant protective role. In blue copper proteins with plastocyanin-like domains, Tyr/Trp clusters are uncommon in the low-potential single-domain electron-transfer proteins and in the two-domain copper nitrite reductases. The two-domain muticopper oxidases, however, exhibit clusters of Tyr and Trp residues near the trinuclear copper active site where O 2 is reduced. These clusters may play a protective role to ensure that reactive oxygen species are not liberated during O 2 reduction.

  6. Evolutionary conservation and changes in insect TRP channels

    OpenAIRE

    Tominaga Makoto; Kohno Keigo; Sokabe Takaaki; Matsuura Hironori; Kadowaki Tatsuhiko

    2009-01-01

    Abstract Background TRP (Transient Receptor Potential) channels respond to diverse stimuli and thus function as the primary integrators of varied sensory information. They are also activated by various compounds and secondary messengers to mediate cell-cell interactions as well as to detect changes in the local environment. Their physiological roles have been primarily characterized only in mice and fruit flies, and evolutionary studies are limited. To understand the evolution of insect TRP c...

  7. Environmental toxin acrolein alters levels of endogenous lipids, including TRP agonists: A potential mechanism for headache driven by TRPA1 activation

    Directory of Open Access Journals (Sweden)

    Emma Leishman

    2017-01-01

    Full Text Available Exposure to airborne toxins can trigger headaches, but the mechanisms are not well understood. Some environmental toxins, such as acrolein, activate transient receptor potential ankyrin 1 (TRPA1, a receptor involved in pain sensation that is highly expressed in the trigeminovascular system. It has been shown in rat models that repeated exposure to acrolein induces trigeminovascular sensitization to both TRPA1 and TRP vanilloid 1 (TRPV1 agonists, a phenomenon linked to headache. In this study, we test the hypothesis that the sensitization of trigeminovascular responses in rats after acrolein exposure via inhalation is associated with changes in levels of endogenous lipids, including TRPV1 agonists, in the trigeminal ganglia, trigeminal nucleus, and cerebellum. Lipidomics analysis of 80 lipids was performed on each tissue after acute acrolein, chronic acrolein, or room air control. Both acute and chronic acrolein exposure drove widespread alterations in lipid levels. After chronic acrolein exposure, levels of all 6 N-acyl ethanolamines in the screening library, including the endogenous cannabinoid and TRPV1 agonist, N-arachidonoyl ethanolamine, were elevated in trigeminal tissue and in the cerebellum. This increase in TRPV1 ligands by acrolein exposure may indicate further downstream signaling, in that we also show here that a combination of these TRPV1 endogenous agonists increases the potency of the individual ligands in TRPV1-HEK cells. In addition to these TRPV1 agonists, 3 TRPV3 antagonists, 4 TRPV4 agonists, and 25 orphan lipids were up and down regulated after acrolein exposure. These data support the hypothesis that lipid signaling may represent a mechanism by which repeated exposure to the TRPA1 agonist and environmental toxin, acrolein, drives trigeminovascular sensitization. Keywords: Lipidomics, Endogenous cannabinoid, TRPA1, TRPV1, Lipoamine, Acrolein, Migraine

  8. Phytoconstituents with Radical Scavenging and Cytotoxic Activities from Diospyros shimbaensis

    Directory of Open Access Journals (Sweden)

    Per Aronsson

    2016-01-01

    Full Text Available As part of our search for natural products having antioxidant and anticancer properties, the phytochemical investigation of Diospyros shimbaensis (Ebenaceae, a plant belonging to a genus widely used in East African traditional medicine, was carried out. From its stem and root barks the new naphthoquinone 8,8′-oxo-biplumbagin (1 was isolated along with the known tetralones trans-isoshinanolone (2 and cis-isoshinanolone (3, and the naphthoquinones plumbagin (4 and 3,3′-biplumbagin (5. Compounds 2, 4, and 5 showed cytotoxicity (IC50 520–82.1 μM against MDA-MB-231 breast cancer cells. Moderate to low cytotoxicity was observed for the hexane, dichloromethane, and methanol extracts of the root bark (IC50 16.1, 29.7 and > 100 μg/mL, respectively, and for the methanol extract of the stem bark (IC50 59.6 μg/mL. The radical scavenging activity of the isolated constituents (1–5 was evaluated on the 2,2-diphenyl-1-picrylhydrazyl (DPPH radical scavenging assay. The applicability of the crude extracts and of the isolated constituents for controlling degenerative diseases is discussed.

  9. Phytoconstituents with Radical Scavenging and Cytotoxic Activities from Diospyros shimbaensis.

    Science.gov (United States)

    Aronsson, Per; Munissi, Joan J E; Gruhonjic, Amra; Fitzpatrick, Paul A; Landberg, Göran; Nyandoro, Stephen S; Erdelyi, Mate

    2016-01-15

    As part of our search for natural products having antioxidant and anticancer properties, the phytochemical investigation of Diospyros shimbaensis (Ebenaceae), a plant belonging to a genus widely used in East African traditional medicine, was carried out. From its stem and root barks the new naphthoquinone 8,8'-oxo-biplumbagin ( 1 ) was isolated along with the known tetralones trans -isoshinanolone ( 2 ) and cis -isoshinanolone ( 3 ), and the naphthoquinones plumbagin ( 4 ) and 3,3'-biplumbagin ( 5 ). Compounds 2 , 4 , and 5 showed cytotoxicity (IC 50 520-82.1 μM) against MDA-MB-231 breast cancer cells. Moderate to low cytotoxicity was observed for the hexane, dichloromethane, and methanol extracts of the root bark (IC 50 16.1, 29.7 and > 100 μg/mL, respectively), and for the methanol extract of the stem bark (IC 50 59.6 μg/mL). The radical scavenging activity of the isolated constituents ( 1 - 5 ) was evaluated on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The applicability of the crude extracts and of the isolated constituents for controlling degenerative diseases is discussed.

  10. Flavonoids: hemisynthesis, reactivity, characterization and free radical scavenging activity.

    Science.gov (United States)

    Es-Safi, Nour-Eddine; Ghidouche, Souhila; Ducrot, Paul Henri

    2007-09-26

    Phenolic compounds form one of the main classes of secondary metabolites. They display a large range of structures and they are responsible for the major organoleptic characteristics of plant-derived-foods and beverages, particularly color and taste properties and they also contribute to the nutritional qualities of fruits and vegetables. Phenolic compounds are also highly unstable compounds which undergo numerous enzymatic and chemical reactions during postharvest food storage and processing thus adding to the complexity of plant polyphenol composition. Among these compounds flavonoids constitute one of the most ubiquitous groups of all plant phenolics. Owing to their importance in food organoleptic properties and in human health, a better understanding of their structures, their reactivity and chemical properties in addition to the mechanisms generating them appears essential to predict and control food quality. The purpose of this work is an overview of our findings concerning the hemisynthesis, the reactivity and the enzymatic oxidation of some flavonoids and shed light on the mechanisms involved in some of these processes and the structures of the resulting products. The free radical scavenging activity of some of the synthesized compounds is also presented and a structure-activity relationship is discussed. The first part of this review concerns the synthesis and structural characterization of modified monomeric flavanols. The use of these compounds as precursor for the preparation of natural and modified dimeric procyanidin derivatives was then explored through different coupling reactions. The full characterization of the synthesized compounds was achieved by concerted use of NMR and ESI-MS techniques. The free radical scavenging activity of some of the synthesized compounds was investigated. The second part of this review concerns the enzymatic oxidation of several flavonols by Trametes versicolor laccase. Most of the major oxidation products have been

  11. Flavonoids: Hemisynthesis, Reactivity, Characterization and Free Radical Scavenging Activity

    Directory of Open Access Journals (Sweden)

    Paul Henri Ducrot

    2007-09-01

    Full Text Available Phenolic compounds form one of the main classes of secondary metabolites. They display a large range of structures and they are responsible for the major organoleptic characteristics of plant-derived-foods and beverages, particularly color and taste properties and they also contribute to the nutritional qualities of fruits and vegetables. Phenolic compounds are also highly unstable compounds which undergo numerous enzymatic and chemical reactions during postharvest food storage and processing thus adding to the complexity of plant polyphenol composition. Among these compounds flavonoids constitute one of the most ubiquitous groups of all plant phenolics. Owing to their importance in food organoleptic properties and in human health, a better understanding of their structures, their reactivity and chemical properties in addition to the mechanisms generating them appears essential to predict and control food quality. The purpose of this work is an overview of our findings concerning the hemisynthesis, the reactivity and the enzymatic oxidation of some flavonoids and shed light on the mechanisms involved in some of these processes and the structures of the resulting products. The free radical scavenging activity of some of the synthesized compounds is also presented and a structure-activity relationship is discussed. The first part of this review concerns the synthesis and structural characterization of modified monomeric flavanols. The use of these compounds as precursor for the preparation of natural and modified dimeric procyanidin derivatives was then explored through different coupling reactions. The full characterization of the synthesized compounds was achieved by concerted use of NMR and ESI-MS techniques. The free radical scavenging activity of some of the synthesized compounds was investigated. The second part of this review concerns the enzymatic oxidation of several flavonols by Trametes versicolor laccase. Most of the major oxidation

  12. Differential radioprotection and free radical scavenging activity of Caesalpinia digyna extracts and the active constituent

    International Nuclear Information System (INIS)

    Singh, Umang; Kunwar, A.; Barik, A.; Priyadarsini, K.I.; Mula, S.; Srinivasan, R.

    2008-01-01

    Differential free radical activity of the fractionated extracts (F1: methanolic fraction, F2: acetone soluble fraction and F3: acetone insoluble fraction) of a medicinal plant Caesalpinia digyna, has been studied employing DPPH, superoxide radical and in vitro radioprotecting activity by following their effect on radiation induced protein carbonylation and DNA damage in pBR322. The activity for these fractions is in the order of F1>F2>F3. HPLC analysis indicated that all fractions contain high amount of bergenin, a polyhydroxy isocoumarin derivative and the fractions are more active than isolated bergenin. (author)

  13. Differential radioprotection and free radical scavenging activity of Caesalpinia digyna extracts and the active constituent

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Umang; Kunwar, A; Barik, A; Priyadarsini, K I [Radiation and Photochemistry Div., Bhabha Atomic Research Centre, Mumbai (India); Mula, S [Bio-Organic Div., Bhabha Atomic Research Centre, Mumbai (India); Srinivasan, R [JSS College of Pharmacy, Ootacamund (India)

    2008-01-15

    Differential free radical activity of the fractionated extracts (F1: methanolic fraction, F2: acetone soluble fraction and F3: acetone insoluble fraction) of a medicinal plant Caesalpinia digyna, has been studied employing DPPH, superoxide radical and in vitro radioprotecting activity by following their effect on radiation induced protein carbonylation and DNA damage in pBR322. The activity for these fractions is in the order of F1>F2>F3. HPLC analysis indicated that all fractions contain high amount of bergenin, a polyhydroxy isocoumarin derivative and the fractions are more active than isolated bergenin. (author)

  14. Structure-activity relationship of linear tetrapeptides Tic-DPhe-Arg-Trp-NH2 at the human melanocortin-4 receptor and effects on feeding behaviors in rat.

    Science.gov (United States)

    Ye, Zhixiong; MacNeil, Tanya; Weinberg, David H; Kalyani, Rubana N; Tang, Rui; Strack, Alison M; Murphy, Beth A; Mosley, Ralph T; Euan MacIntyre, D; Van der Ploeg, Lex H T; Patchett, Arthur A; Wyvratt, Matthew J; Nargund, Ravi P

    2005-10-01

    The melanocortin subtype-4 receptor (MC4R) has been implicated in the control of feeding behavior and body weight regulation. A series of tetrapeptides, based on Tic-DPhe-Arg-Trp-NH2-a mimic of the putative message sequence "His-Phe-Arg-Trp" and modified at the DPhe position, were prepared and pharmacologically characterized for potency and selectivity. Substitution of His with Tic gave peptides with significant increases in selectivity. The effects of the substitution pattern of DPhe were investigated and it has significant influences on potency and the level of the maximum cAMP accumulation. Intracerebroventricular administration of peptide 10 induced significant inhibition of cumulative overnight food intake and feeding duration in rats.

  15. Studies on free radical scavenging activity in Chinese seaweeds part I. Screening results

    Science.gov (United States)

    Yan, Xiao-Jun; Fang, Guo-Ming; Lou, Qing-Xiang

    1999-09-01

    Antioxidants have attracted the attention of researchers due to their beneficial effects as free radical scavengers. Application of a stable free radical named 1, 1-diphenyl-2-picrylhydrazyl(DPPH) to screen the free radical scavenging activity in 27 species of Chinese seaweed showed that 15 of them had significant activity in at least one of the organic solvent extracts. The most interesting seaweed species were Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres.

  16. Management Approaches to Radical Social Media Activism: the responses of BP, HSBC and Nestlé to Greenpeace

    OpenAIRE

    Grant, Bettina

    2010-01-01

    Corporate directed radical activism has been reframed by the internet and social media, which provide radical activists with new tools to mount innovative attack forms against corporations. These attack forms (herein termed by author as radical social media activism) happen in the digital sphere and augment radical attack forms in the physical world. Corporations are challenged with a new age of radical activism and, thus far, have displayed low competence at using social media to manage this...

  17. TrpA1 activation in peripheral sensory neurons underlies the ionic basis of pain hypersensitivity in response to vinca alkaloids.

    Directory of Open Access Journals (Sweden)

    Nina Boiko

    Full Text Available Chemotherapy induced peripheral neuropathy (CIPN, a side effect of many anti-cancer drugs including the vinca alkaloids, is characterized by a severe pain syndrome that compromises treatment in many patients. Currently there are no effective treatments for this pain syndrome except for the reduction of anti-cancer drug dose. Existing data supports the model that the pain associated with CIPN is the result of anti-cancer drugs augmenting the function of the peripheral sensory nociceptors but the cellular mechanisms underlying the effects of anti-cancer drugs on sensory neuron function are not well described. Studies from animal models have suggested a number of disease etiologies including mitotoxicity, axonal degeneration, immune signaling, and reduced sensory innervations but these outcomes are the result of prolonged treatment paradigms and do not necessarily represent the early formative events associated with CIPN. Here we show that acute exposure to vinca alkaloids results in an immediate pain syndrome in both flies and mice. Furthermore, we demonstrate that exposure of isolated sensory neurons to vinca alkaloids results in the generation of an inward sodium current capable of depolarizing these neurons to threshold resulting in neuronal firing. These neuronal effects of vinca alkaloids require the transient receptor potential ankyrin-1 (TrpA1 channel, and the hypersensitization to painful stimuli in response to the acute exposure to vinca alkaloids is reduced in TrpA1 mutant flies and mice. These findings demonstrate the direct excitation of sensory neurons by CIPN-causing chemotherapy drugs, and identify TrpA1 as an important target during the pathogenesis of CIPN.

  18. Efficient peroxydisulfate activation process not relying on sulfate radical generation for water pollutant degradation

    KAUST Repository

    Zhang, Tao; Chen, Yin; Wang, Yuru; Le Roux, Julien; Yang, Yang; Croue, Jean-Philippe

    2014-01-01

    Peroxydisulfate (PDS) is an appealing oxidant for contaminated groundwater and toxic industrial wastewaters. Activation of PDS is necessary for application because of its low reactivity. Present activation processes always generate sulfate radicals

  19. Measurement of radical scavenging activity of irradiated Kampo extracts using ESR spin-trap method

    International Nuclear Information System (INIS)

    Ohta, Yui; Kawamura, Shoei; Ukai, Mitsuko; Nakamura, Hideo; Kikuchi, Masahiro; Kobayashi, Yasuhiko

    2014-01-01

    The radical scavenging activity (RSA) of 13 kinds of γ-ray irradiated Kampo extracts were studied by ESR spin-trap method. The RSA against alkoxy radical and hydroxyl radical were measured using new spin trapping reagent CYPMPO. The RSA against these two radicals were evaluated using GSH for alkoxy RSA and L-ascorbic acid for hydroxy RSA as a standard antioxidant reagent. We revealed that a few Kampo extracts showed high RSA against alkoxy radical and also hydroxy radical. This RSA of Kampo extracts was changed by γ-ray irradiation treatment. Using ESR spin-trap method, it is concluded that the effect of radiation treatment on RSA of Kampo extracts were able to detect. (author)

  20. Evolutionary conservation and changes in insect TRP channels.

    Science.gov (United States)

    Matsuura, Hironori; Sokabe, Takaaki; Kohno, Keigo; Tominaga, Makoto; Kadowaki, Tatsuhiko

    2009-09-10

    TRP (Transient Receptor Potential) channels respond to diverse stimuli and thus function as the primary integrators of varied sensory information. They are also activated by various compounds and secondary messengers to mediate cell-cell interactions as well as to detect changes in the local environment. Their physiological roles have been primarily characterized only in mice and fruit flies, and evolutionary studies are limited. To understand the evolution of insect TRP channels and the mechanisms of integrating sensory inputs in insects, we have identified and compared TRP channel genes in Drosophila melanogaster, Bombyx mori, Tribolium castaneum, Apis mellifera, Nasonia vitripennis, and Pediculus humanus genomes as part of genome sequencing efforts. All the insects examined have 2 TRPV, 1 TRPN, 1 TRPM, 3 TRPC, and 1 TRPML subfamily members, demonstrating that these channels have the ancient origins in insects. The common pattern also suggests that the mechanisms for detecting mechanical and visual stimuli and maintaining lysosomal functions may be evolutionarily well conserved in insects. However, a TRPP channel, the most ancient TRP channel, is missing in B. mori, A. mellifera, and N. vitripennis. Although P. humanus and D. melanogaster contain 4 TRPA subfamily members, the other insects have 5 TRPA subfamily members. T. castaneum, A. mellifera, and N. vitripennis contain TRPA5 channels, which have been specifically retained or gained in Coleoptera and Hymenoptera. Furthermore, TRPA1, which functions for thermotaxis in Drosophila, is missing in A. mellifera and N. vitripennis; however, they have other Hymenoptera-specific TRPA channels (AmHsTRPA and NvHsTRPA). NvHsTRPA expressed in HEK293 cells is activated by temperature increase, demonstrating that HsTRPAs function as novel thermal sensors in Hymenoptera. The total number of insect TRP family members is 13-14, approximately half that of mammalian TRP family members. As shown for mammalian TRP channels, this

  1. Evolutionary conservation and changes in insect TRP channels

    Directory of Open Access Journals (Sweden)

    Tominaga Makoto

    2009-09-01

    Full Text Available Abstract Background TRP (Transient Receptor Potential channels respond to diverse stimuli and thus function as the primary integrators of varied sensory information. They are also activated by various compounds and secondary messengers to mediate cell-cell interactions as well as to detect changes in the local environment. Their physiological roles have been primarily characterized only in mice and fruit flies, and evolutionary studies are limited. To understand the evolution of insect TRP channels and the mechanisms of integrating sensory inputs in insects, we have identified and compared TRP channel genes in Drosophila melanogaster, Bombyx mori, Tribolium castaneum, Apis mellifera, Nasonia vitripennis, and Pediculus humanus genomes as part of genome sequencing efforts. Results All the insects examined have 2 TRPV, 1 TRPN, 1 TRPM, 3 TRPC, and 1 TRPML subfamily members, demonstrating that these channels have the ancient origins in insects. The common pattern also suggests that the mechanisms for detecting mechanical and visual stimuli and maintaining lysosomal functions may be evolutionarily well conserved in insects. However, a TRPP channel, the most ancient TRP channel, is missing in B. mori, A. mellifera, and N. vitripennis. Although P. humanus and D. melanogaster contain 4 TRPA subfamily members, the other insects have 5 TRPA subfamily members. T. castaneum, A. mellifera, and N. vitripennis contain TRPA5 channels, which have been specifically retained or gained in Coleoptera and Hymenoptera. Furthermore, TRPA1, which functions for thermotaxis in Drosophila, is missing in A. mellifera and N. vitripennis; however, they have other Hymenoptera-specific TRPA channels (AmHsTRPA and NvHsTRPA. NvHsTRPA expressed in HEK293 cells is activated by temperature increase, demonstrating that HsTRPAs function as novel thermal sensors in Hymenoptera. Conclusion The total number of insect TRP family members is 13-14, approximately half that of mammalian TRP

  2. Radical-scavenging Activity of Natural Methoxyphenols vs. Synthetic Ones using the Induction Period Method

    Directory of Open Access Journals (Sweden)

    Seiichiro Fujisawa

    2007-02-01

    Full Text Available The radical-scavenging activities of the synthetic antioxidants 2-allyl-4-X-phenol (X=NO2, Cl, Br, OCH3, COCH3, CH3, t-(CH33, C6H5 and 2,4-dimethoxyphenol, and the natural antioxidants eugenol and isoeugenol, were investigated using differential scanning calorimetry (DSC by measuring their anti-1,1-diphenyl-2-picrylhydrazyl (DPPH radical activity and the induction period for polymerization of methyl methacrylate (MMA initiated by thermal decomposition of 2,2'-azobisisobutyronitrile (AIBN and benzoyl peroxide (BPO. 2-Allyl-4-methoxyphenol and 2,4-dimethoxy-phenol scavenged not only oxygen-centered radicals (PhCOO. derived from BPO, but also carbon-centered radicals (R. derived from the AIBN and DPPH radical much more efficiently, in comparison with eugenol and isoeugenol. 2-Allyl-4-methoxyphenol may be useful for its lower prooxidative activity.

  3. Sub-cellular distribution and translocation of TRP channels.

    Science.gov (United States)

    Toro, Carlos A; Arias, Luis A; Brauchi, Sebastian

    2011-01-01

    Cellular electrical activity is the result of a highly complex processes that involve the activation of ion channel proteins. Ion channels make pores on cell membranes that rapidly transit between conductive and non-conductive states, allowing different ions to flow down their electrochemical gradients across cell membranes. In the case of neuronal cells, ion channel activity orchestrates action potentials traveling through axons, enabling electrical communication between cells in distant parts of the body. Somatic sensation -our ability to feel touch, temperature and noxious stimuli- require ion channels able to sense and respond to our peripheral environment. Sensory integration involves the summing of various environmental cues and their conversion into electrical signals. Members of the Transient Receptor Potential (TRP) family of ion channels have emerged as important mediators of both cellular sensing and sensory integration. The regulation of the spatial and temporal distribution of membrane receptors is recognized as an important mechanism for controlling the magnitude of the cellular response and the time scale on which cellular signaling occurs. Several studies have shown that this mechanism is also used by TRP channels to modulate cellular response and ultimately fulfill their physiological function as sensors. However, the inner-working of this mode of control for TRP channels remains poorly understood. The question of whether TRPs intrinsically regulate their own vesicular trafficking or weather the dynamic regulation of TRP channel residence on the cell surface is caused by extrinsic changes in the rates of vesicle insertion or retrieval remain open. This review will examine the evidence that sub-cellular redistribution of TRP channels plays an important role in regulating their activity and explore the mechanisms that control the trafficking of vesicles containing TRP channels.

  4. Free radical scavenging activities of pigment extract from Hibiscus ...

    African Journals Online (AJOL)

    AJL

    2012-01-05

    Jan 5, 2012 ... molecules by getting electrons from them (Lien et al.,. 2008; Perry et al., ... of the filtrate was adjusted to 80% with 95% ethanol. The ..... Free Radical bio. Med. ... Antioxidant properties of banana flower of two cultivars in China using 2 ... total phenolic contents in peel and pulp of Chinese jujube (Ziziphus.

  5. Screening of various botanical extracts for antioxidant activity using DPPH free radical method.

    Science.gov (United States)

    Waqas, Muhammad Khurram; Saqib, Najam-Us; Rashid, Saeed-Ur; Shah, Pervaiz Akhtar; Akhtar, Naveed; Murtaza, Ghulam

    2013-01-01

    Aiming at the exploration of herbal use by society, crude extracts of the seeds of some commonly used medicinal plants (Vitis vinifera, Tamarindus indica and Glycin max) were screened for their free radical scavenging properties using ascorbic acid as standard antioxidant. Free radical scavenging activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. The overall antioxidant activity of grape seeds (Vitis vinifera) was the strongest, followed in descending order by soybean (Glycin max) and tamarind (Tamarindus indica). The seeds extract of Vitis vinifera, Glycin max and Tamarindus indica showed 85.61%, 83.45% and 79.26%, DPPH scavenging activity respectively.

  6. The scavenger activities of tea polyphenol and quercetin against oxygen radicals

    International Nuclear Information System (INIS)

    Fang Ruoying; Cheng Jiwu; Hu Tianxi; Tu Tiecheng; Dong Jirong; Wang Wenfeng; Lin nianyun

    1992-01-01

    Studies of free radical biology and medicine have shown that carcinogenesis, vascular diseases of heart and brain, radiation injuries, ageing etc are strictly correlated with free radical injury of tissues. Thus, pharmacologists and biologists are focusing attention on searching for scavengers, especially naturally occurring antioxidant of oxidizing free radicals. Previous studies have indicated that phenolic antioxidants have efficient scavenger activities. Utilizing following methods including chemical luminescence, ESR spectroscopy and pulse radiolysis techniques the scavenger activities of tea polyphenols and quercetin against active species of oxygen have been studied

  7. Melanocortin tetrapeptide Ac-His-DPhe-Arg-Trp-NH2 modified at the para position of the benzyl side chain (DPhe): importance for mouse melanocortin-3 receptor agonist versus antagonist activity.

    Science.gov (United States)

    Proneth, Bettina; Pogozheva, Irina D; Portillo, Federico P; Mosberg, Henry I; Haskell-Luevano, Carrie

    2008-09-25

    The melanocortin-3 and -4 receptors (MC3R, MC4R) have been implicated in energy homeostasis and obesity. Whereas the physiological role of the MC4R is extensively studied, little is known about the MC3R. One caveat is the limited availability of ligands that are selective for the MC3R. Previous studies identified Ac-His-DPhe(p-I)-Arg-Trp-NH 2, which possessed partial agonist/antagonist pharmacology at the mMC3R while retaining full nanomolar agonist pharmacology at the mMC4R. These data allowed for the hypothesis that the DPhe position in melanocortin tetrapeptides can be used to examine ligand side-chain determinants important for differentiation of mMC3R agonist versus antagonist activity. A series of 15 DPhe (7) modified Ac-His-DPhe (7)-Arg-Trp-NH 2 tetrapeptides has been synthesized and pharmacologically characterized. Most notable results include the identification of modifications that resulted in potent antagonists/partial agonists at the mMC3R and full, potent agonists at the mMC4R. These SAR studies provide experimental evidence that the molecular mechanism of antagonism at the mMC3R differentiates this subtype from the mMC4R.

  8. TRP channel proteins and signal transduction.

    Science.gov (United States)

    Minke, Baruch; Cook, Boaz

    2002-04-01

    TRP channel proteins constitute a large and diverse family of proteins that are expressed in many tissues and cell types. This family was designated TRP because of a spontaneously occurring Drosophila mutant lacking TRP that responded to a continuous light with a transient receptor potential (hence TRP). In addition to responses to light, TRPs mediate responses to nerve growth factor, pheromones, olfaction, mechanical, chemical, temperature, pH, osmolarity, vasorelaxation of blood vessels, and metabolic stress. Furthermore, mutations in several members of TRP-related channel proteins are responsible for several diseases, such as several tumors and neurodegenerative disorders. TRP-related channel proteins are found in a variety of organisms, tissues, and cell types, including nonexcitable, smooth muscle, and neuronal cells. The large functional diversity of TRPs is also reflected in their diverse permeability to ions, although, in general, they are classified as nonselective cationic channels. The molecular domains that are conserved in all members of the TRP family constitute parts of the transmembrane domains and in most members also the ankyrin-like repeats at the NH2 terminal of the protein and a "TRP domain" at the COOH terminal, which is a highly conserved 25-amino acid stretch with still unknown function. All of the above features suggest that members of the TRP family are "special assignment" channels, which are recruited to diverse signaling pathways. The channels' roles and characteristics such as gating mechanism, regulation, and permeability are determined by evolution according to the specific functional requirements.

  9. Radical heterosexuality: Straight teacher activism in schools : Does ally-led activism work?

    Directory of Open Access Journals (Sweden)

    Leigh Potvin

    2016-06-01

    Here, I explore the efficacy of straight teacher allies, the importance of understanding straight privilege, and the significance of radical heterosexuality for straight people doing LGBTQ activism. Relying on queer theory and decolonizing/Indigenous queer theory, I argue that it is necessary for straight teachers to acknowledge their straight privilege in order to challenge homophobia's companions: heterosexism and heteronormativity. In addressing the latter two covert forms of oppression in schools, teachers and students could shift into deeper, more effective resistance measures.

  10. Oxidation of free, peptide and protein tryptophan residues mediated by AAPH-derived free radicals: role of alkoxyl and peroxyl radicals

    DEFF Research Database (Denmark)

    Fuentes-Lemus, E.; Dorta, E.; Escobar, E.

    2016-01-01

    The oxidation of tryptophan (Trp) residues, mediated by peroxyl radicals (ROOc), follows a complex mechanism involving free radical intermediates, and short chain reactions. The reactivity of Trp towards ROOc should be strongly affected by its inclusion in peptides and proteins. To examine...... the latter, we investigated (by fluorescence) the kinetic of the consumption of free, peptide- and protein-Trp residues towards AAPH (2,20 -azobis(2-amidinopropane)dihydrochloride)-derived free radicals. Interestingly, the initial consumption rates (Ri ) were only slightly influenced by the inclusion of Trp...... concentrations (10–50 mM), the values of Ri were nearly constant; and at high Trp concentrations (50 mM to 1 mM), a slower increase of Ri than expected for chain reactions. Similar behavior was detected for all three systems (free Trp, and Trp in peptides and proteins). For the first time we are showing...

  11. Phytochemical Screening and Free Radical Scavenging Activities of ...

    African Journals Online (AJOL)

    Total phenolic, total flavonoid and proanthocyanidin contents were 65, 0.07 and 2.38 mg/g of powdered plant material for AF fruits, and 12, 51.35, 19.5 mg/g of powdered plant material for AF leaves as gallic acid, rutin and catechin equivalents respectively. Conclusion: AF leaves are five times more potent as a free radical ...

  12. Nociceptive TRP Channels: Sensory Detectors and Transducers in Multiple Pain Pathologies

    Directory of Open Access Journals (Sweden)

    Aaron D. Mickle

    2016-11-01

    Full Text Available Specialized receptors belonging to the transient receptor potential (TRP family of ligand-gated ion channels constitute the critical detectors and transducers of pain-causing stimuli. Nociceptive TRP channels are predominantly expressed by distinct subsets of sensory neurons of the peripheral nervous system. Several of these TRP channels are also expressed in neurons of the central nervous system, and in non-neuronal cells that communicate with sensory nerves. Nociceptive TRPs are activated by specific physico-chemical stimuli to provide the excitatory trigger in neurons. In addition, decades of research has identified a large number of immune and neuromodulators as mediators of nociceptive TRP channel activation during injury, inflammatory and other pathological conditions. These findings have led to aggressive targeting of TRP channels for the development of new-generation analgesics. This review summarizes the complex activation and/or modulation of nociceptive TRP channels under pathophysiological conditions, and how these changes underlie acute and chronic pain conditions. Furthermore, development of small-molecule antagonists for several TRP channels as analgesics, and the positive and negative outcomes of these drugs in clinical trials are discussed. Understanding the diverse functional and modulatory properties of nociceptive TRP channels is critical to function-based drug targeting for the development of evidence-based and efficacious new generation analgesics.

  13. Screening of radical scavenging activity of some medicinal and aromatic plant extracts

    NARCIS (Netherlands)

    Miliauskas, G.; Venskutonis, R.P.; Beek, van T.A.

    2004-01-01

    Extracts of 12 medicinal and aromatic plants were investigated for their radical scavenging activity using DPPH and ABTS assays: Salvia sclarea, Salvia glutinosa, Salvia pratensis, Lavandula angustifolia, Calendula officinalis, Matricaria recutita, Echinacea purpurea, Rhaponticum carthamoides,

  14. [Correlation Between Functional Groups and Radical Scavenging Activities of Acidic Polysaccharides from Dendrobium].

    Science.gov (United States)

    Liao, Ying; Yuan, Wen-yu; Zheng, Wen-ke; Luo, Ao-xue; Fan, Yi-jun

    2015-11-01

    To compare the radical scavenging activity of five different acidic polysaccharides, and to find the correlation with the functional groups. Alkali extraction method and Stepwise ethanol precipitation method were used to extract and concentrate the five Dendrobium polysaccharides, and to determine the contents of sulfuric acid and uronic acid of each kind of acidic polysaccharides, and the scavenging activity to ABTS+ radical and hydroxyl radical. Functional group structures were examined by FTIR Spectrometer. Five kinds of Dendrobium polysaccharides had different ability of scavenging ABTS+ free radical and hydroxyl free radical. Moreover, the study had shown that five kinds of antioxidant activity of acidic polysaccharides had obvious correlation withuronic acid and sulfuric acid. The antioxidant activity of each sample was positively correlated with the content of uronic acid, and negatively correlated with the content of sulfuric acid. Sulfuric acid can inhibit the antioxidant activity of acidic polysaccharide but uronic acid can enhance the free radical scavenging activity. By analyzing the structure characteristics of five acidic polysaccharides, all samples have similar structures, however, Dendrobium denneanum, Dendrobium devonianum and Dendrobium officinale which had β configuration have higher antioxidant activity than Dendrobium nobile and Dendrobium fimbriatum which had a configuration.

  15. Polyphenolic Compounds and Free Radical Scavenging Activity in Eight Lamiaceae Herbs of Manipur

    Directory of Open Access Journals (Sweden)

    Sandhyarani Devi KHOMDRAM

    2011-05-01

    Full Text Available Eight plants of Lamiaceae under subfamily Nepetoideae found in Manipur, India were selected for estimation of their polyphenolic compounds and free radical scavenging activity which is expressed on dry weight basis. In this present study, the total phenol and flavonoid contents as well as the free radical scavenging activity were studied using spectrophotometric method. The total phenol content was determined based on Folin-Ciocalteau reagent, flavonoid was determined by aluminium chloride spectrophotometric method and tannin by Folin Dennis Method. The free radical scavenging activity was determined by using DPPH radical which is expressed as IC50 (μg/ml. The total phenolic content varied from 21.39±0.927 to 46.28±0.543 mg/g, flavonoids content in the selected samples varied from 13.30±0.684 to 26.03±0.217 mg/g and tannin content varied from 8.72±0.160 to 17.04±0.206 mg/g. The free radical scavenging activity among the selected samples varied from 11.67±0.221 to 38.29±0.532 μg/ml. The correlation between the free radical scavenging activity with total phenol content (R2=0.511, with flavonoids (R2=0.241 and with tannin (R2=0.690 was calculated and maximum correlation value was found between tannin content and the free radical scavenging activity of the plant samples. The result supports that tannins were more responsible for free radical scavenging activity in the presently selected plants.

  16. Xanthine oxidase activity and free radical generation in patients with sepsis syndrome

    DEFF Research Database (Denmark)

    Galley, H F; Davies, Michael Jonathan; Webster, N R

    1996-01-01

    OBJECTIVE: To determine xanthine oxidase activity, free radical concentrations, and lipid peroxidation in patients with sepsis syndrome compared with noninfected critically ill patients. DESIGN: A prospective observational study. SETTING: A nine-bed intensive care unit in a university teaching......). CONCLUSIONS: Patients with sepsis have xanthine oxidase activation, high free-radical concentrations, and evidence of free radical damage. The finding that xanthine oxidase activity was lower in those patients who died, coupled with increased lactate concentrations implies more severe ischemia with incomplete...... to the Acute Physiology and Chronic Health Evaluation (APACHE) II score or to the presence of organ dysfunction. The mean ascorbyl radical concentration (arbitrary units) determined by electron paramagnetic resonance following spin trapping was increased in patients compared with healthy subjects (p

  17. [In vitro anti-inflammatory and free radical scavenging activities of flavans from Ilex centrochinensis].

    Science.gov (United States)

    Li, Lu-jun; Yu, Li-juan; Li, Yan-ci; Liu, Meng-yuan; Wu, Zheng-zhi

    2015-04-01

    This study was carried out to evaluate the anti-inflammatory and free radical scavenging activities of flavans from flex centrochinensis S. Y. Hu in vitro and their structure-activity relationship. LPS-stimulated RAW 264.7 macrophage was used as inflammatory model. MTT assay for cell availability, Griess reaction for nitric oxide (NO) production, the content of TNF-alpha, IL-1beta, IL-6 and PGE, were detected with ELISA kits; DPPH, superoxide anion and hydroxyl free radicals scavenging activities were also investigated. According to the result, all flavans tested exhibited anti-inflammatory effect in different levels. Among them, compounds 1, 3, 4 and 6 showed potent anti-inflammatory effect through the inhibition of NO, TNF-alpha, IL-lp and IL-6, of which 1 was the most effective inhibitor, however, 2 and 5 were relatively weak or inactive. The order of free radical scavenging activities was similar to that of anti-inflammatory activities. Therefore, these results suggest that 3, 4 and 6, especially of 1, were,in part responsible for the anti-inflammatory and free radical scavenging activity of Ilex centrochinensis. Hydroxyl group at 4'-position of B-ring plays an important role in the anti-inflammatory and free radical scavenging capacities.

  18. Radiation-initiated free-radical fragmentation of biologically active glycerides

    International Nuclear Information System (INIS)

    Akhrem, A.A.; Kisel', M.A.; Shadyro, O.I.; Yurkova, I.L.

    1993-01-01

    Oxidation reactions of the free-radical type play a decisive role in the initial processes of radiation damage. The most suitable substrates for such reactions are lipids. Lipids are a basic structural element of biomembranes and are involved in the barrier function and biocatalytic activity of such membranes. Free-radical degradation of membrane lipids can lead to serious damage and ultimately to destruction of the living cell. A well-studied type of free-radical conversion of lipids is oxidation of polyunsaturated fatty acid residues, so-called peroxide oxidation of lipids. In this paper, using as examples dimyristoylphosphatidyl glycerol (DMPG), monoglycerides, and glycerophosphate, the authors investigated the possibility of free-radical degradation in compounds of a lipid nature containing the α,β-bifunctional group

  19. Free radical scavenging activities of yellow gentian (Gentiana lutea L.) measured by electron spin resonance.

    Science.gov (United States)

    Kusar, A; Zupancic, A; Sentjurc, M; Baricevic, D

    2006-10-01

    Yellow gentian (Gentiana lutea L.) is a herbal species with a long-term use in traditional medicine due to its digestive and stomachic properties. This paper presents an investigation of the free radical scavenging activity of methanolic extracts of yellow gentian leaves and roots in two different systems using electron spin resonance (ESR) spectrometry. Assays were based on the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the superoxide radicals (O2*-) generated by the xanthine/xanthine oxidase (X/XO) system. The results of gentian methanolic extracts were compared with the antioxidant capacity of synthetic antioxidant butylated hydroxyanisole (BHA). This study proves that yellow gentian leaves and roots exhibit considerable antioxidant properties, expressed either by their capability to scavenge DPPH or superoxide radicals.

  20. Free radical scavenging activity and lipoxygenase inhibition of Mahonia aquifolium extract and isoquinoline alkaloids

    Directory of Open Access Journals (Sweden)

    Kettmann Viktor

    2007-07-01

    Full Text Available Abstract Roots and stem-bark of Mahonia aquifolium (Oregon grape (Berberidaceae are effectively used in the treatment of skin inflammatory conditions. In the present study, the effect of Mahonia aquifolium crude extract and its two representative alkaloid fractions containing protoberberine and bisbenzylisoquinoline (BBIQ alkaloids on activity of 12-lipoxygenase (12-LOX, was studied. The reactivity with 1,1-diphenyl-2-picryl-hydrazyl (DPPH, a free stable radical, was evaluated to elucidate the rate of possible lipid-derived radical scavenging in the mechanism of the enzyme inhibition. The results indicate that although the direct radical scavenging mechanism cannot be ruled out in the lipoxygenase inhibition by Mahonia aquifolium and its constituents, other mechanisms based on specific interaction between enzyme and alkaloids could play the critical role in the lipoxygenase inhibition rather than non-specific reactivity with free radicals.

  1. Fluorescence kinetics of Trp-Trp dipeptide and its derivatives in water via ultrafast fluorescence spectroscopy.

    Science.gov (United States)

    Jia, Menghui; Yi, Hua; Chang, Mengfang; Cao, Xiaodan; Li, Lei; Zhou, Zhongneng; Pan, Haifeng; Chen, Yan; Zhang, Sanjun; Xu, Jianhua

    2015-08-01

    Ultrafast fluorescence dynamics of Tryptophan-Tryptophan (Trp-Trp/Trp2) dipeptide and its derivatives in water have been investigated using a picosecond resolved time correlated single photon counting (TCSPC) apparatus together with a femtosecond resolved upconversion spectrophotofluorometer. The fluorescence decay profiles at multiple wavelengths were fitted by a global analysis technique. Nanosecond fluorescence kinetics of Trp2, N-tert-butyl carbonyl oxygen-N'-aldehyde group-l-tryptophan-l-tryptophan (NBTrp2), l-tryptophan-l-tryptophan methyl ester (Trp2Me), and N-acetyl-l-tryptophan-l-tryptophan methyl ester (NATrp2Me) exhibit multi-exponential decays with the average lifetimes of 1.99, 3.04, 0.72 and 1.22ns, respectively. Due to the intramolecular interaction between two Trp residues, the "water relaxation" lifetime was observed around 4ps, and it is noticed that Trp2 and its derivatives also exhibit a new decay with a lifetime of ∼100ps, while single-Trp fluorescence decay in dipeptides/proteins shows 20-30ps. The intramolecular interaction lifetime constants of Trp2, NBTrp2, Trp2Me and NATrp2Me were then calculated to be 3.64, 0.93, 11.52 and 2.40ns, respectively. Candidate mechanisms (including heterogeneity, solvent relaxation, quasi static self-quenching or ET/PT quenching) have been discussed. Copyright © 2015. Published by Elsevier B.V.

  2. Activism and radical politics in the digital age: Towards a typology

    DEFF Research Database (Denmark)

    Neumayer, Christina; Jakob, Svensson

    2014-01-01

    This article aims to develop a typology for evaluating different types of activism in the digital age, based on the ideal of radical democracy. Departing from this ideal, activism is approached in terms of processes of identification by establishing conflictual frontiers to outside others as either...... in radical democracy concerning developing frontiers. The second axis, about readiness to engage in civil disobedience, is derived from a review of studies of different forms of online activism. The article concludes by suggesting that the different forms of political engagement online have to be taken...

  3. Evaluation of free radical scavenging activity of tea infusion of commercial tea products available in uae

    International Nuclear Information System (INIS)

    Nessa, F.; Khan, S.A.

    2014-01-01

    In the present study, twenty four commercial tea samples were assayed to determine their free radical scavenging activity and polyphenolic contents based on the brewing/infusing period. Tea samples were infused/brewed in 200 mL boiled water at 120 degree C for 1, 2 and 5 min, respectively. The radical scavenging activities of tea infusion/brewing were measured using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay method. The results were ranged from 67.81-90.51% for black tea bags, 90.37-94.51% for green tea bags, 24.66-92.25% for black tea powder, 16.08-93.06% for green tea powder and 32.90- 45.54% for Camomile herbal infusion. The results showed that 1 or 2 min black tea bags infusion exhibited highest radical scavenging activity than 5 min infusion. Antioxidant activities of tea powders were variable with the amount of tea powder. It was observed that antioxidant activity increased with increasing boiling time for smaller amount of sample. In contrary, shorter boiling time was better for larger amount of sample. The polyphenol contents of tea infusion were determined and the results were expressed as milligram quercetin equivalent/200 mL of tea infusion. The polyphenol content was increased with increased brewing period. In contrary, brewing for longer time rendered extract less antiradical activity. This study suggests that infusing tea bag for 1 or 2 min is sufficient for getting infusion with maximum radical scavenging activity and in case of tea powder, shorter boiling time is better for larger amount of powder or small amount of powder should be boiled for minimum 5 min for rendering extract with maximum radical scavenging activity. (author)

  4. Monovalent Cation Activation of the Radical SAM Enzyme Pyruvate Formate-Lyase Activating Enzyme.

    Science.gov (United States)

    Shisler, Krista A; Hutcheson, Rachel U; Horitani, Masaki; Duschene, Kaitlin S; Crain, Adam V; Byer, Amanda S; Shepard, Eric M; Rasmussen, Ashley; Yang, Jian; Broderick, William E; Vey, Jessica L; Drennan, Catherine L; Hoffman, Brian M; Broderick, Joan B

    2017-08-30

    Pyruvate formate-lyase activating enzyme (PFL-AE) is a radical S-adenosyl-l-methionine (SAM) enzyme that installs a catalytically essential glycyl radical on pyruvate formate-lyase. We show that PFL-AE binds a catalytically essential monovalent cation at its active site, yet another parallel with B 12 enzymes, and we characterize this cation site by a combination of structural, biochemical, and spectroscopic approaches. Refinement of the PFL-AE crystal structure reveals Na + as the most likely ion present in the solved structures, and pulsed electron nuclear double resonance (ENDOR) demonstrates that the same cation site is occupied by 23 Na in the solution state of the as-isolated enzyme. A SAM carboxylate-oxygen is an M + ligand, and EPR and circular dichroism spectroscopies reveal that both the site occupancy and the identity of the cation perturb the electronic properties of the SAM-chelated iron-sulfur cluster. ENDOR studies of the PFL-AE/[ 13 C-methyl]-SAM complex show that the target sulfonium positioning varies with the cation, while the observation of an isotropic hyperfine coupling to the cation by ENDOR measurements establishes its intimate, SAM-mediated interaction with the cluster. This monovalent cation site controls enzyme activity: (i) PFL-AE in the absence of any simple monovalent cations has little-no activity; and (ii) among monocations, going down Group 1 of the periodic table from Li + to Cs + , PFL-AE activity sharply maximizes at K + , with NH 4 + closely matching the efficacy of K + . PFL-AE is thus a type I M + -activated enzyme whose M + controls reactivity by interactions with the cosubstrate, SAM, which is bound to the catalytic iron-sulfur cluster.

  5. In vitro free radical scavenging activity of ethanolic extract of the whole plant of Evolvulus alsinoides (L.) L.

    Science.gov (United States)

    Gomathi, Duraisamy; Ravikumar, Ganesan; Kalaiselvi, Manokaran; Vidya, Balasubramaniam; Uma, Chandrasekar

    2015-06-01

    To identify the free radical scavenging activity of ethanolic extract of Evolvulus alsinoides. The free radical scavenging activity was evaluated by in vitro methods like reducing power assay, total antioxidant activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) reduction, superoxide radical scavenging activity, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(+)) scavenging activity, hydroxyl radical scavenging assay, and nitric oxide radical scavenging assay, which were studied by using ascorbic acid as standard. The extract showed significant activities in all antioxidant assays compared with the reference antioxidant ascorbic acid. The total antioxidant activity as well as the reducing power was also found to increase in a dose-dependent manner. Evolvulus alsinoides may act as a chemopreventive agent, providing antioxidant properties and offering effective protection from free radicals.

  6. Highly functionalized piperidines: Free radical scavenging, anticancer activity, DNA interaction and correlation with biological activity

    OpenAIRE

    Suvankar Das; Cristiane J. da Silva; Marina de M. Silva; Maria Dayanne de A. Dantas; Ângelo de Fátima; Ana Lúcia T. Góis Ruiz; Cleiton M. da Silva; João Ernesto de Carvalho; Josué C.C. Santos; Isis M. Figueiredo; Edeildo F. da Silva-Júnior; Thiago M. de Aquino; João X. de Araújo-Júnior; Goutam Brahmachari; Luzia Valentina Modolo

    2018-01-01

    Twenty-five piperidines were studied as potential radical scavengers and antitumor agents. Quantitative interaction of compounds with ctDNA using spectroscopic techniques was also evaluated. Our results demonstrate that the evaluated piperidines possesses different abilities to scavenge the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the anion radical superoxide (·O2−). The piperidine 19 was the most potent radical DPPH scavenger, while the most effective to ·O2− scavenger was piperidine...

  7. Preliminary assay on the radical scavenging activity of olive wood extracts

    NARCIS (Netherlands)

    Altarejos, J.; Salido, S.; Pérez-Bonilla, M.; Linares-Palomino, P.J.; Beek, van T.A.; Nogueras, M.; Sánchez, A.

    2005-01-01

    The dichloromethane and ethanol extracts of Olea europaea wood (picual olive cultivar) were screened for antioxidant activity, determined by the DPPH free radical scavenging assay. The ethanol extract displayed potent antioxidant activity. (c) 2005 Elsevier B.V. All rights reserved.

  8. Free radical scavenging activity of coenzyme Q measured by a chemiluminescent assay

    International Nuclear Information System (INIS)

    Battino, Maurizio; Ferri, Elida; Girotti, Stefano; Lenaz, Giorgio

    1991-01-01

    Involvement of coenzyme Q (CoQ) in anti-oxydant activities, in addition to its major redox role, has frequently been suggested in recent years. In order to elucidate if CoQ could really be engaged in scavenging free radicals produced endogenously in a biological system, an experimental system was developed in which beef heart mitochondria in the presence of a saturating NADH concentration and of rotenone produce free radicals. The presence of oxygen-reactive forms was easily detected by a luminol-dependent chemiluminescence process. The chemi-luminescence assay showed that short-chain CoQ homologues can act as pro-oxidants, enhancing free radical effects, while exogenous coenzyme Q 10 could scavenge free radicals, especially at very low concentration. In this system, exogenous CoQ 10 was more effective than α-tocopherol at the same concentration in scavenging free radicals. The molecular mechanism that leads to this activity is still unclear, but these results are of biochemical importance because they indicate that CoQ may act as an anti=oxidant in situations mimicking physiopathological conditions. This direct chemiluminescent method is promising for studies of biochemical processes which involve active oxygen species. (author). 24 refs.; 4 figs

  9. Activity of Oligoresveratrols from Stem Bark of Hopea mengarawan (Dipterocarpaceae as Hydroxyl Radical Scavenger

    Directory of Open Access Journals (Sweden)

    SRI ATUN

    2006-06-01

    Full Text Available Four oligoresveratrols ranging from dimer to tetramer, isolated from stem bark of Hopea mengarawan (Dipterocarpaceae plants were tested for their activity as hydroxyl radical scavenger. The activity of these compounds was evaluated against the 2-deoxyribose degradation induced by the hydroxyl radical generated via a Fenton-type reaction. Result showed that balanocarpol, heimiol A, vaticanol G, and vaticanol B had IC50 3.83; 15.44; 2.01; and 4.71 µM, respectively. These results suggest that oligoresveratrols from stem bark of H. mengarawan maybe useful as potential sources of natural antioxidants.

  10. Phytochemical Analysis and Free Radical Scavenging Activity of Medicinal Plants Gnidia glauca and Dioscorea bulbifera

    Science.gov (United States)

    Ghosh, Sougata; Derle, Abhishek; Ahire, Mehul; More, Piyush; Jagtap, Soham; Phadatare, Suvarna D.; Patil, Ajay B.; Jabgunde, Amit M.; Sharma, Geeta K.; Shinde, Vaishali S.; Pardesi, Karishma; Dhavale, Dilip D.; Chopade, Balu A.

    2013-01-01

    Gnidia glauca and Dioscorea bulbifera are traditional medicinal plants that can be considered as sources of natural antioxidants. Herein we report the phytochemical analysis and free radical scavenging activity of their sequential extracts. Phenolic and flavonoid content were determined. Scavenging activity was checked against pulse radiolysis generated ABTS•+ and OH radical, in addition to DPPH, superoxide and hydroxyl radicals by biochemical methods followed by principal component analysis. G. glauca leaf extracts were rich in phenolic and flavonoid content. Ethyl acetate extract of D. bulbifera bulbs and methanol extract of G. glauca stem exhibited excellent scavenging of pulse radiolysis generated ABTS•+ radical with a second order rate constant of 2.33×106 and 1.72×106, respectively. Similarly, methanol extract of G. glauca flower and ethyl acetate extract of D. bulbifera bulb with second order rate constants of 4.48×106 and 4.46×106 were found to be potent scavengers of pulse radiolysis generated OH radical. G. glauca leaf and stem showed excellent reducing activity and free radical scavenging activity. HPTLC fingerprinting, carried out in mobile phase, chloroform: toluene: ethanol (4: 4: 1, v/v) showed presence of florescent compound at 366 nm as well as UV active compound at 254 nm. GC-TOF-MS analysis revealed the predominance of diphenyl sulfone as major compound in G. glauca. Significant levels of n-hexadecanoic acid and octadecanoic acid were also present. Diosgenin (C27H42O3) and diosgenin (3á,25R) acetate were present as major phytoconstituents in the extracts of D. bulbifera. G. glauca and D. bulbifera contain significant amounts of phytochemicals with antioxidative properties that can be exploited as a potential source for herbal remedy for oxidative stress induced diseases. These results rationalize further investigation in the potential discovery of new natural bioactive principles from these two important medicinal plants. PMID:24367520

  11. Superoxide radical formation, superoxide dismutase and glutathione reductase activity in the brain of irradiated rats

    International Nuclear Information System (INIS)

    Stanimirovic, D.; Ivanovic, L.; Simovic, M.; Cernak, I.; Savic, J.

    1989-01-01

    In the forebrain cortex, basal ganglia and hippocampus of irradiated rats (whole body, X-ray, 9 Gy), nitroblue-tetrazolium (NBT) reduction was measured as a probe of superoxide radical formation 1 hr, 6 hrs, 24 hrs and 72 hrs after irradiation. Increased superoxide radical formation was found in parallel with increase of superoxide dismutase (SOD) activity and marked decrease of glutathione reductase (GR) activity which is the most pronounced in basal ganglia. The results indicate that in the postradiation period disproportion among free radical production and capacity of brain antioxidative system occurs. This disbalance is more expressed in the brain regions known as selective vulnerable (basal ganglia, hippocampus). (author). 10 refs.; 2 tabs

  12. Exploring the Role of Persulfate in the Activation Process: Radical Precursor Versus Electron Acceptor.

    Science.gov (United States)

    Yun, Eun-Tae; Yoo, Ha-Young; Bae, Hyokwan; Kim, Hyoung-Il; Lee, Jaesang

    2017-09-05

    This study elucidates the mechanism behind persulfate activation by exploring the role of various oxyanions (e.g., peroxymonosulfate, periodate, and peracetate) in two activation systems utilizing iron nanoparticle (nFe 0 ) as the reducing agent and single-wall carbon nanotubes (CNTs) as electron transfer mediators. Since the tested oxyanions serve as both electron acceptors and radical precursors in most cases, oxidative degradation of organics was achievable through one-electron reduction of oxyanions on nFe 0 (leading to radical-induced oxidation) and electron transfer mediation from organics to oxyanions on CNTs (leading to oxidative decomposition involving no radical formation). A distinction between degradative reaction mechanisms of the nFe 0 /oxyanion and CNT/oxyanion systems was made in terms of the oxyanion consumption efficacy, radical scavenging effect, and EPR spectral analysis. Statistical study of substrate-specificity and product distribution implied that the reaction route induced on nFe 0 varies depending on the oxyanion (i.e., oxyanion-derived radical), whereas the similar reaction pathway initiates organic oxidation in the CNT/oxyanion system irrespective of the oxyanion type. Chronoamperometric measurements further confirmed electron transfer from organics to oxyanions in the presence of CNTs, which was not observed when applying nFe 0 instead.

  13. In vitro antibacterial and radical scavenging activities of Malaysian ...

    African Journals Online (AJOL)

    The EtOH extract of this plant was the only one that showed inhibition against Candida albicans. ... (GAE/g dry extract). The results showed that some table salads (ulam) possess antimicrobial and antioxidant activities and therefore, could be used as a natural preservative ingredient in food and/or pharmaceutical industries.

  14. In vitro antioxidant and free radical scavenging activity of Leonurus ...

    African Journals Online (AJOL)

    The total phenolic compounds in the extracts were determined as gallic acid equivalents, and total flavonoid contents were calculated as quercetin equivalents from a calibration curve. Keywords: Antioxidant activity, Fe2+ chelating, 1,1-diphenyl-2-picryl hydrazyl (DPPH), phenol, Leonurus cardiaca, Grammosciadium ...

  15. Antioxidant and free radical scavenging activities of plant extracts ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... venging mechanism as part of their activity (Perry et al.,. 1999; Lin ... are used in traditional medicine (Argueta et al., 1994;. Monroy-Ortíz ..... Bermejo P, Iglesias I, Abad MJ, Gómez-Serranillos P, Liso PA, Villar. A, Chiriboga X ...

  16. Free-radical scavenging capacity and antimicrobial activity of wild ...

    African Journals Online (AJOL)

    ... Escherichia coli, Morganella morganii and Proteus vulgaris. The antimicrobial activity profile of R. flava against tested strains indicated that Micrococcus flavus, Micrococcus luteus and Yersinia enterocolitica was the most susceptible bacteria of all the test strains. R. flava was found to be inactive against Candida albicans.

  17. Free radical scavenging activity and phenolic content of Cassia ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... used as additives to avoid the degradation of foods. Also, antioxidants have ... these are closely related to the active oxygen and lipid peroxidation .... In recent years, the biological and pharma- cological effects of ... effects on human health. They occur ... Diet Nutrition and Health, twentieth ed. Papas. M. P. ...

  18. Thermo-sensitive TRP channels in peripheral nerve injury: a review of their role in cold intolerance.

    Science.gov (United States)

    Kambiz, S; Duraku, L S; Holstege, J C; Hovius, S E R; Ruigrok, T J H; Walbeehm, E T

    2014-05-01

    One of the sensory complications of traumatic peripheral nerve injury is thermal intolerance, which manifests in humans mainly as cold intolerance. It has a major effect on the quality of life, and adequate therapy is not yet available. In order to better understand the pathophysiological background of thermal intolerance, we focus first on the various transient receptor potential (TRP) channels that are involved in temperature sensation, including their presence in peripheral nerves and in keratinocytes. Second, the role of thermo-sensitive TRP channels in cold and heat intolerance is described showing three different mechanisms that contribute to thermal intolerance in the skin: (a) an increased expression of TRP channels on nerve fibres and on keratinocytes, (b) a lower activation threshold of TRP channels and (c) the sprouting of non-injured nerve fibres. Finally, the data that are available on the effects of TRP channel agonists and antagonists and their clinical use are discussed. In conclusion, TRP channels play a major role in temperature sensation and in cold and heat intolerance. Unfortunately, the available pharmaceutical agents that successfully target TRP channels and counteract thermal intolerance are still very limited. Yet, our focus should remain on TRP channels since it is difficult to imagine a reliable treatment for thermal intolerance that will not involve TRP channels. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  19. Sexual function with localized prostate cancer: active surveillance vs radical therapy

    NARCIS (Netherlands)

    van den Bergh, Roderick C. N.; Korfage, Ida J.; Roobol, Monique J.; Bangma, Chris H.; de Koning, Harry J.; Steyerberg, Ewout W.; Essink-Bot, Marie-Louise

    2012-01-01

    OBJECTIVE To compare sexual function of men with localized prostate cancer (PCa) on active surveillance (AS) with similar patients who received radical therapy. PATIENTS AND METHODS Two groups of men with screening-detected localized PCa were compared. The first were men on AS within the prospective

  20. In vitro anti-radical activities of extracts of Solanum nigrum (L.) from ...

    African Journals Online (AJOL)

    SARAH

    2016-02-29

    Feb 29, 2016 ... activities observed in this study. The isolation and .... acetate (CH3CO2K), ascorbic acid, rutin, glacial acetic acid (CH3COOH), Folin- ..... and volatile oils that can chelate metals and donate H+ to oxygen radicals, thus making ...

  1. In vitro anti-inflammatory and free radical scavenging activities of ...

    African Journals Online (AJOL)

    Methods: In vitro antioxidant activity was determined using free radical scavenging assays such as DPPH, ABTS and NO2. The antiinflammatory potential was carried out using inhibition of protein denaturation of egg albumin as a model of anti-inflammatory capacity. Results: Both the crude methanolic extract and saponins ...

  2. Biological activity of clovers - free radical scavenging ability and antioxidant action of six Trifolium species.

    Science.gov (United States)

    Kolodziejczyk-Czepas, Joanna; Nowak, Pawel; Kowalska, Iwona; Stochmal, Anna

    2014-10-01

    Clovers were chosen on the basis of traditional medicine recommendations, agricultural value, or available information on their promising chemical profiles. This study evaluates and compares free radical scavenging and antioxidant properties of six clover species: Trifolium alexandrinum L. (Leguminosae), Trifolium fragiferum L., Trifolium hybridum L., Trifolium incarnatum L., Trifolium resupinatum var. majus Boiss., and Trifolium resupinatum var. resupinatum L. Free radical scavenging activity of the extracts (1.5-50 µg/ml) was estimated by reduction of 1,1-diphenyl-2-picrylhydrazyl (DPPH(•)) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic) acid (ABTS(•)) radicals. The Trifolium extract effects on total antioxidant capacity of blood plasma were determined by the reduction of ABTS(•+) and DPPH(•) radicals, as well as with the use of the ferric reducing ability of plasma (FRAP) assay. The UPLC analysis of chemical profiles of the examined extracts showed the presence of three or four groups of phenolic substances, including phenolic acids, clovamides, isoflavones, and other flavonoids. The measurements of free radical scavenging and ferric reducing ability of the examined clover extracts revealed the strongest effect for T. alexandrinum. Furthermore, antioxidant activity assays in human plasma have shown protective effects of all extracts against peroxynitrite-induced reduction of total antioxidant capacity. Trifolium plants may be a rich source of bioactive substances with antioxidant properties. The examined extracts displayed free radical scavenging action and partly protected blood plasma against peroxynitrite-induced oxidative stress; however, the beneficial effects of T. alexandrinum and T. incarnatum seem to be slightly higher.

  3. [Photometric micro-titration model of DPPH radicals scavenging activity and its application].

    Science.gov (United States)

    Gao, Yun-tao; Wei, Wei; Ye, Li-qing; Li, Xiao-fen; Liu, Ping; Zhang, Hong-jiao; Yang, Lu; Yu, Jiao-jiao; Cha, Jia-wei

    2015-02-01

    In the present paper, the stoichiometric ratio (R) for the interreaction of DPPH radicals with the antoxidant was employed as a evaluation index for DPPH radicals scavenging activity of antioxidants. This evaluation index was related only with the stoichiometric relationship between DPPH radicals and the antioxidant, not the relationship with the initial DPPH amount and the volume of sample, which could offer a solution for the problem of poor comparability of EC50 under different conditions. A novel photometric micro-titration method was proposed for the determination of the stoichiometric ratio (R) for the interreaction of DPPH radicals with the antoxidant. The titration equation was established based on the absorbance difference (deltaA) of DPPH radicals in the titration process and the added amount of antoxidant. The stoichiometric ratio (R) for the reaction of DPPH radicals with the addition amount of antoxidant was determined by the titration equation obtained, while, the DPPH median elimination concentration (EC50) of antoxidant can be calculated by the stoichiometric ratio (R). The above photometric micro-titration model was verified using rutin as DPPH radicals scavenger. As experiment results, the stoichiometric ratio (R) of DPPH radicals to rutin was determined to be in the range of 1.817-1.846. The calculated value of EC50 was 1.196 x 10(-3), 2.392 x 10(-3), 4.819 x 10(-3) and 7.292 x 10(-3) mg x mL(-1) for 1.12 x 10(-7), 2.24 x 10(-7), 4.48 x 10(-7) and 6.72 x 10(-7) mol of the additon amount of DPPH radicals, respectively. The proposed method has better precision and reliability with smaller amount of sample than conventional method. While, the obtained stoichiometric ratio value (R) of rutin was employed to calculate the rutin median elimination concentration for DPPH EC50) according to the conditions as reported in the literatures, and the calculated results were consistent with that reported in the literatures.

  4. Free radical activity during development of insulin-dependent diabetes mellitus in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Pitkaenen, O.M.; Akerblom, H.K.; Sariola, H.; Andersson, S.M. (Univ. of Helsinki (Finland)); Martin, J.M. (Hospital for Sick Children, Toronto, Ontario (Canada)); Hallman, M. (Univ. of California, Irvine (United States))

    1991-01-01

    Free radical-induced lipid peroxidation was quantified by measuring expired pentane from diabetic prone BB Wistar rats of 45-90 d of age. Insulin-dependent diabetes mellitus was manifest at the age of 71 {plus minus} 8 d. Expired pentane increased from 2.1 {plus minus} 0.7 to 5.0 {plus minus}3.0 pmol/100g/min (p <0.01) at manifestation of the disease and remained high throughout the test period. In healthy age-matched control rats it persisted low. In rats made diabetic with streptozotocin, expired pentane remained low. The changes in expired pentane suggest that the development of endogenous insulin-dependent diabetes mellitus in BB rats is associated with increased free radical activity. This is not due to hyperglycemia or ketosis per se, and reflects a fundamental difference in the free radical activity between the spontaneously diabetic BB rats and the disease produced by streptozotocin. Development of spontaneous insulin-dependent diabetes in BB rats is associated with increased free radical activity that persists after the manifestation of the disease.

  5. Extraction and free radical scavenging activity of polysaccharide from 'Anji Baicha' (Camellia sinensis (L.) O. Kuntze).

    Science.gov (United States)

    Zhang, Zhongshan; Wang, Xiaomei; Li, Jingfen; Wang, Guozhi; Mao, Genxiang

    2016-03-01

    In this study, the optimization of the extraction conditions of polysaccharide from 'Anji Baicha' (Camellia sinensis (L.) O. Kuntze) (AP) was investigated by response surface methodology (RSM). Three main independent variables (extraction temperature, time, ratio of water to raw material) were taken into consideration. And then the free radical scavenging activities of the sample were investigated including scavenging effects of superoxide and hydroxyl radicals. The RSM analysis showed good correspondence between experimental and predicted values.. The optimal condition to obtain the highest yield of AP was determined as follows: temperature 76.79 °C, time 2.48 h, ratio of water to material 22.53 mL/g. For the free radical scavenging activity, the IC50 values of Vc and AP were 7.78 and 83.25 μg/mL. And for the scavenging effect on hydroxyl radical, that of AP and Vc were 1.80 and 1.69 mg/mL. AP showed excellent antioxidant activity. This exhibited AP had a good potential for antioxidant. The purification and structure needs to be study in further. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Radical-scavenging-linked antioxidant activities of extracts from black chokeberry and blueberry cultivated in Korea.

    Science.gov (United States)

    Hwang, Seok Joon; Yoon, Won Byong; Lee, Ok-Hwan; Cha, Seung Ju; Kim, Jong Dai

    2014-03-01

    The objective of this study was to investigate the radical-scavenging-linked antioxidant properties of the extracts from black chokeberry and blueberry cultivated in Korea. The 70% ethanol extracts were prepared from black chokeberry and blueberry, and evaluated for total phenolic content, total flavonoid content, total proanthocyanidin content, and antioxidative activities, using various in vitro assays, such as DPPH(2,2-diphenyl-1-picrylhydrazyl), ABTS(2,2-azino-bis-(3-ethylenebenzothiozoline-6-sulphonic acid)) radical-scavenging activity, FRAP(ferric-reducing antioxidant power) and reducing power. The major phenolic compounds, including cyanidin-3-galactoside, cyanidin-3-arabinoside, neochlorogenic acid, procyanidin B1, were analysed by HPLC with a photodiode array detector. Results showed that total phenol, flavonoid and proanthocyanidin contents of black chokeberry extract were higher than those of blueberry extract. In addition, black chokeberry extract exhibited higher free radical-scavenging activity and reducing power than did blueberry extract. Cyanidin-3-galactoside was identified as a major phenolic compound, with considerable content in black chokeberry, that correlated with its higher antioxidant and radical-scavenging effects. These results suggest that black chokeberry extracts could be considered as a good source of natural antioxidants and functional food ingredients. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Chemical Constituents with Free-Radical-Scavenging Activities from the Stem of Microcos paniculata

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2010-08-01

    Full Text Available The free-radical-scavenging activities of various solvent extracts of Microcos paniculata were evaluated through in vitro model systems, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH, 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate (ABTS and Co (II EDTA-induced luminol chemiluminescence by flow injection. In all three of these systems the ethyl acetate (EtOAc extract showed the highest free-radical-scavenging activity compared with the other three (n-BuOH, water and petroleum ether extracts. Free-radical-scavenging assay-guided chromatographic separation of the EtOAc extract, using a normal-phase and reverse-phase silica gel column chromatography yielded five compounds: a new triterpene named methyl 3b-O-p-hydroxy-E-cinnamoyloxy-2a,23-dihydroxyolean-12-en-28-oate (1, whose spectral data are presented for the first time, together with four known compounds, epicatechin (2, 3-trans-feruloyl maslinic acid (3, maslinic acid (4 and sucrose (5. All of the compounds were isolated from Microcos paniculata for the first time. The compounds were identified by spectroscopic methods. Among them, compound 2 displayed significant free-radical-scavenging activity which is similar to that of standard antioxidant ascorbic acid (VC and therefore may be a promising natural antioxidant.

  8. In vitro antibacterial and free radical scavenging activity of green hull of Juglans regia

    Directory of Open Access Journals (Sweden)

    Pardeep Sharma

    2013-08-01

    Full Text Available Antioxidant supplements from plants are vital to count the oxidative damage in cells. We assessed the antioxidants and antibacterial activity of green hull of Juglans regia in this study. According to our results the maximum antibacterial activity was observed in ethanolic extract when compared to other extract. So, the ethanolic extract was studied for antioxidant activity which exhibited high antiradical activity against DPPH, hydroxyl, and nitric oxide radicals. In conclusion, green hull of J. regia showed strong reducing power activity and total antioxidant capacity. The results justify the therapeutic application of plant in the indigenous system of medicine. Keywords: Juglans regia, Ethanolic extract, Antioxidants, DPPH, Antibacterial activity

  9. Safety evaluation of Tokai reprocessing plant (TRP). Report of safety evaluation of Tokai reprocessing plant

    International Nuclear Information System (INIS)

    Yamauchi, Takamichi; Maki, Akira; Nojiri, Ichiro

    1999-02-01

    The fire and explosion incident of the bituminization facility happened in March 1997 although JNC had taken enough care of the safety of TRP. JNC reflected on it and decided to evaluate the safety of TRP voluntarily. This evaluation has included five activities, that is, (1) confirmation of the structure and organization of TRP, (2) research of the data for operation, radiation and maintenance of TRP, (3) research of reflection of the accidents and troubles which have happened at the past, (4) evaluation on the prevention system, (5) evaluation on the mitigation system. We publish this report to contribute to inheritance of accumulated knowledge and techniques from generation to generation, and remind us of lesson from the fire and explosion incident of the bituminization. (author)

  10. Alkylperoxyl radical scavenging activity of red leaf lettuce (Lactuca sativa L.) phenolics.

    Science.gov (United States)

    Caldwell, Charles R

    2003-07-30

    Although lettuce may provide relatively low levels of antioxidative phytochemicals which may contribute to human health, lettuce leaf extracts in fact contained compounds with high specific peroxyl radical scavenging activities. After determining the extraction conditions that minimized phenolic oxidation and produced the highest oxygen radical absorbance capacity (ORAC) values, the phenolic compounds from red leaf lettuce were separated by reverse-phase high-performance liquid chromatography (HPLC). The primary phenolic compounds in the leaf tissue extracts were mono- and dicaffeoyltartaric acid (CTA and DCTA), mono- and dicaffeoylquinic acid (CQA and DCQA), quercetin 3-malonylglucoside (QMG), quercetin 3-glucoside (QG), cyanidin 3-malonylglucoside (CMG), and an unknown phenolic ester (UPE). Significant levels of DCQA were only found after wounding. Using the new fluorescein-based ORAC assay procedures, fractions from the HPLC analyses were assayed for peroxyl radical absorbance capacity. Using absorbance to estimate concentration, the decreasing order of contribution to the total ORAC value of an extract from wounded tissue was QMG > DCQA > CMG > DCTA > UPE > QG > CTA. The decreasing order of the specific peroxyl radical scavenging activities was CMG > QG > DCTA > DCQA > QMG > UPE > CQA > CTA. Since the concentrations of plant flavonoid and phenolic acid esters are sensitive to environmental factors, this information may be used to develop pre- and postharvest conditions which increase the dietary benefits of leaf lettuce.

  11. Synthesis and in Vitro Antioxidant Activity Evaluation of 3-Carboxycoumarin Derivatives and QSAR Study of Their DPPH• Radical Scavenging Activity

    Directory of Open Access Journals (Sweden)

    Maria Teresa Sumaya-Martínez

    2012-12-01

    Full Text Available The in vitro antioxidant activities of eight 3-carboxycoumarin derivatives were assayed by the quantitative 1,1-diphenyl-2-picrylhydrazil (DPPH• radical scavenging activity method. 3-Acetyl-6-hydroxy-2H-1-benzopyran-2-one (C1 and ethyl 6-hydroxy-2-oxo-2H-1-benzopyran-3-carboxylate (C2 presented the best radical-scavenging activity. A quantitative structure-activity relationship (QSAR study was performed and correlated with the experimental DPPH• scavenging data. We used structural, geometrical, topological and quantum-chemical descriptors selected with Genetic Algorithms in order to determine which of these parameters are responsible of the observed DPPH• radical scavenging activity. We constructed a back propagation neural network with the hydrophilic factor (Hy descriptor to generate an adequate architecture of neurons for the system description. The mathematical model showed a multiple determination coefficient of 0.9196 and a root mean squared error of 0.0851. Our results shows that the presence of hydroxyl groups on the ring structure of 3-carboxy-coumarins are correlated with the observed DPPH• radical scavenging activity effects.

  12. Evaluation of Radical Scavenging Activity of Sempervivum tectorum and Corylus avellana Extracts with Different Phenolic Composition.

    Science.gov (United States)

    Alberti, Ágnes; Riethmüller, Eszter; Béni, Szabolcs; Kéry, Ágnes

    2016-04-01

    Semnpervivum tectorum L. and Corylus avellana L. are traditional herbal remedies exhibiting antioxidant activity and representing diverse phenolic composition. The aim of this study was to reveal the contribution of certain compounds to total radical scavenging activity by studying S. tectorum and C. avellana extracts prepared with solvents of different selectivity for diverse classes of phenolics. Antioxidant activity of S. tectorum and C. avellana samples was determined in the ABTS and DPPH radical scavenging assays, and phenolic composition was evaluated by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Correlations between antioxidant activity and phenolic content of houseleek extracts have been revealed. Significant differences regarding antioxidant activity have been shown between S. tectorum 80% (v/v) methanol extract and its fractions. Additionally, synergism among the constituents present together in the whole extract was assumed. Significantly higher radical scavenging activity of hazel extracts has been attributed to the differences in phenolic composition compared with houseleek extracts.

  13. Expression of the benign HEXA mutations, Arg247Trp and Arg249Trp, associated with beta-hexosaminidase A pseudodeficiency

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Z.; Petroulakis, E.; Salo, T. [Univ. of Manitoba (Canada)] [and others

    1994-09-01

    {beta}-Hexosaminidase (Hex A) is a heterodimer of {alpha} and {beta} subunits encoded by the HEXA and HEXB genes, respectively. Mutations in the HEXA gene typically cause Tay-Sachs disease or less severe forms of G{sub M2} gangliosidosis. However, two benign mutations (Arg247Trp and Arg249Trp) in the {alpha}-subunit of Hex A account for Hex A deficiency in {approximately}36% of non-Jewish enzyme-defined Tay-Sachs disease carriers. These mutations do not result in any apparent clinical phenotype in individuals who are genetic compounds with a second disease-causing mutation. We expressed the {alpha}-subunit harboring each of the benign mutations separately to study activity toward the synthetic substrate, 4-MUGS, for comparison to activity from enzymes containing mutations associated with other forms of G{sub M2} gangliosidosis. The C739T (Arg247Trp;benign), C745T (Arg 249Trp; benign), G805A (Gly269Ser; adult-onset), G749A (Gly250Asp; juvenile), and C508T (Arg170Trp; infantile) mutations were introduced into the {alpha}-subunit cDNA. These were transfected alone, or with the {beta}-subunit cDNA, to generate Hex S ({alpha}{alpha}) or Hex A ({alpha}{beta}), respectively. The activities were monitored using 4-MUGS, and the levels of {alpha}-subunit protein were assessed by Western blotting. Repeated experiments show that the benign mutations produce approximately 35% of normal Hex S and 40% of normal Hex A activity. This level is much higher than that of Hex A harbouring the Gly169Ser adult-onset mutation (12%). A sequential decrease in expressed Hex A activity is observed as mutations associated with more severe phenotypes are expressed. The benign mutations also result in lower levels of mature {alpha}-subunit protein compared to normal, and slightly reduced levels of {alpha}-subunit precursor protein. The Hex A deficiency resulting from benign mutations is not as great as that associated with disease-causing mutations.

  14. Anti-free radical activities of kaempferol isolated from Acacia nilotica (L.) Willd. Ex. Del.

    Science.gov (United States)

    Singh, Rajbir; Singh, Bikram; Singh, Sukhpreet; Kumar, Neeraj; Kumar, Subodh; Arora, Saroj

    2008-12-01

    In the present study the polyphenolic compound has been isolated from methanol extract of Acacia nilotica Willd. Ex. Del. which has been identified as kaempferol (AN-5) by NMR and mass spectroscopy. The antioxidant potential of the AN-5 was demonstrated in several in vitro assays: measuring the proton radical scavenging activity (DPPH scavenging assay), hydroxyl radical scavenging activity (deoxyribose degradation assay), metal chelating activity, reducing power and inhibition of lipid peroxidation. It was found that the effect of the compound AN-5 was strongly dose dependent up to the concentrations 1-50 microg/ml in DPPH assay and 1-100 microg/ml in deoxyribose degradation assay but did not show further change above the highest concentrations.

  15. Antioxidant and free radical scavenging activities of Gastrodia elata Bl. and Uncaria rhynchophylla (Miq.) Jacks.

    Science.gov (United States)

    Liu, J; Mori, A

    1992-12-01

    Gastrodia elata Bl. (GE) and Uncaria rhynchophylla (Miq.) Jacks (UR) are two traditional Chinese medicinal herbal drugs, used for the treatment of convulsions and epilepsy. Their antioxidant effects in vivo and their free radical scavenging effects in vitro were investigated. Epileptogenic foci in the lateral brain of the rat were induced by the injection of ferric chloride into the lateral cortex. Both extracts significantly inhibited the increase in levels of lipid peroxide in the ipsilateral cortex, at all times observed. In addition, the two extracts also induced an early increase of activity of superoxide dismutase in the mitochondrial fraction of the ipsilateral cortex. In in vitro experiments, the two extracts exhibited significant dose-dependent scavenging effects on free radicals, using electron spin resonance spectroscopy. These results suggest that the proposed antiepileptic effects of GE and UR may be attributable to the antioxidant activity of the active components in these two medicinal herbs.

  16. Total phenolic and phytosterol compounds and the radical scavenging activity of germinated Australian sweet lupin flour.

    Science.gov (United States)

    Rumiyati; Jayasena, Vijay; James, Anthony P

    2013-12-01

    In addition to their favourable nutritional profile, legumes also contain a range of bioactive compounds such as phenolic compounds and phytosterols which may protect against chronic diseases including cancer and cardiovascular disease. Germination of some legume seeds has been previously reported to increase the concentration of the bioactive compounds. In this study, the effect of germination of Australian Sweet Lupin (ASL) seeds for 9 days on the concentration of some bioactive compounds and the radical scavenging activity in the resulting flour was determined. The concentration of total phenolic compounds in methanolic extracts of germinated ASL flour was determined using Folin Ciocalteu reagent and phytosterols in oil extracts were analyzed by gas-liquid chromatography. The methanolic and oil extracts were also used to determine radical scavenging activity toward 2,2-diphenyl-1-picrylhydrazyl. In the methanolic extracts of germinated ASL flour, phenolic contents and the antioxidant activity were significantly increased following germination (700 and 1400 %, respectively). Analysis of the oil extracts of germinated ASL flour revealed that the concentration of phytosterols and the antioxidant activity were also increased significantly compared to ungerminated ASL flour (300 and 800 %, respectively). The relative proportion of phytosterols in germinated ASL flour was: β-sitosterol (60 %), stigmasterol (30 %) and campesterol (10 %). Germination increases the concentration of bioactive compounds and the radical scavenging activity in the germinated ASL flour.

  17. Radical Scavenging Activity From Ethanolic Extract Of Malvaceae Family’s Flowers

    Science.gov (United States)

    Artanti, A. N.; Rahmadanny, N.; Prihapsara, F.

    2018-04-01

    Sea hibiscus flower (Hibiscus tiliaceus L.), shoe flower (Hibiscus rosa-sinensis L.), and turk’s cap flower (Malvaviscus arboreus Cav.) are a plant that belongs to the same family, Malvaceae. There are expected contain of anthocyanins as active compound. Several studied shows that some flowers could protect human body from free radical danger exposure. This study has been done to examine ethanolic extract from malvaceae family’s which has potency as radical scavenger. Antiradical activity assay was determined by DPPH method with IC50 value as parameter. Based on the study the malvaceae family’s flower was contain of tannins, polyphenols, saponin, and anthocyanine. The radical scavenging activity respectively from the lowest to the higest activity are vitamin c (4,05 ppm ± 0,094), Turk’s cap flower (6,80 ppm ± 0,22), shoe flower (14,62 ppm ± 0,104) and sea hibiscus flower (38,8 ppm ± 0,086). The three of the extract was having strong antioxidant activity.

  18. Efficient peroxydisulfate activation process not relying on sulfate radical generation for water pollutant degradation.

    Science.gov (United States)

    Zhang, Tao; Chen, Yin; Wang, Yuru; Le Roux, Julien; Yang, Yang; Croué, Jean-Philippe

    2014-05-20

    Peroxydisulfate (PDS) is an appealing oxidant for contaminated groundwater and toxic industrial wastewaters. Activation of PDS is necessary for application because of its low reactivity. Present activation processes always generate sulfate radicals as actual oxidants which unselectively oxidize organics and halide anions reducing oxidation capacity of PDS and producing toxic halogenated products. Here we report that copper oxide (CuO) can efficiently activate PDS under mild conditions without producing sulfate radicals. The PDS/CuO coupled process is most efficient at neutral pH for decomposing a model compound, 2,4-dichlorophenol (2,4-DCP). In a continuous-flow reaction with an empty-bed contact time of 0.55 min, over 90% of 2,4-DCP (initially 20 μM) and 90% of adsorbable organic chlorine (AOCl) can be removed at the PDS/2,4-DCP molar ratio of 1 and 4, respectively. Based on kinetic study and surface characterization, PDS is proposed to be first activated by CuO through outer-sphere interaction, the rate-limiting step, followed by a rapid reaction with 2,4-DCP present in the solution. In the presence of ubiquitous chloride ions in groundwater/industrial wastewater, the PDS/CuO oxidation shows significant advantages over sulfate radical oxidation by achieving much higher 2,4-DCP degradation capacity and avoiding the formation of highly chlorinated degradation products. This work provides a new way of PDS activation for contaminant removal.

  19. Evaluation of antioxidant, free radical scavenging and antimicrobial, activity of Quercus incana Roxb.

    Directory of Open Access Journals (Sweden)

    Rizwana eSarwar

    2015-11-01

    Full Text Available Considering the indigenous utilization of Quercus incana Roxb., the present study deals with the investigation of antioxidant, free radical scavenging activity, total phenolic content and antimicrobial activity of Quercus incana Roxb. In vitro antioxidant activity of the plant fractions were determined by DPPH and NO scavenging method. Total phenolic contents were determined by gallic acid equivalent (GAE and antimicrobial activities were determined by agar well diffusion method. It was observed that Quercus incana Roxb. showed significant antibacterial activity against Gram-positive and Gram-negative bacteria. n-Butanol fraction showed maximum activity against Micrococcus leuteus with 19 mm zone of inhibition. n-Butanol fraction of Quercus incana Roxb. showed immense antifungal activity against Aspergillus niger (32 mm ± 0.55 and Aspergillus flavus (28 mm ± 0.45. Similarly n-butanol fraction showed relatively good antioxidant activity with IC50 value of 55.4 ± 0.21μg/mL. The NO scavenging activity of ethyl acetate fraction (IC50 = 23.21 ± 0.31 μg/mL was fairly good compared to other fractions. The current study of Quercus incana Roxb. suggests the presences of synergetic action of some biological active compounds that may be present in the leaves of medicinal plant. Further studies are needed to better characterize the important active constituents responsible for the antimicrobial, antioxidant and free radical scavenging activity.

  20. Novel Water Soluble Chitosan Derivatives with 1,2,3-Triazolium and Their Free Radical-Scavenging Activity.

    Science.gov (United States)

    Li, Qing; Sun, Xueqi; Gu, Guodong; Guo, Zhanyong

    2018-03-28

    Chitosan is an abundant and renewable polysaccharide, which exhibits attractive bioactivities and natural properties. Improvement such as chemical modification of chitosan is often performed for its potential of providing high bioactivity and good water solubility. A new class of chitosan derivatives possessing 1,2,3-triazolium charged units by associating "click reaction" with efficient 1,2,3-triazole quaternization were designed and synthesized. Their free radical-scavenging activity against three free radicals was tested. The inhibitory property and water solubility of the synthesized chitosan derivatives exhibited a remarkable improvement over chitosan. It is hypothesized that triazole or triazolium groups enable the synthesized chitosan to possess obviously better radical-scavenging activity. Moreover, the scavenging activity against superoxide radical of chitosan derivatives with triazolium (IC 50 radical-scavenging assay, the same pattern were observed, which should be related to the triazolium grafted at the periphery of molecular chains.

  1. Free-Radical-Scavenging, Antityrosinase, and Cellular Melanogenesis Inhibitory Activities of Synthetic Isoflavones.

    Science.gov (United States)

    Lu, Tzy-Ming; Ko, Horng-Huey; Ng, Lean-Teik; Hsieh, Yen-Pin

    2015-06-01

    In this study, we examined the potential of synthetic isoflavones for application in cosmeceuticals. Twenty-five isoflavones were synthesized and their capacities of free-radical-scavenging and mushroom tyrosinase inhibition, as well as their impact on cell viability of B16F10 murine melanoma cells and HaCaT human keratinocytes were evaluated. Isoflavones that showed significant mushroom tyrosinase inhibitory activities were further studied on reduction of cellular melanin formation and antityrosinase activities in B16F10 melanocytes in vitro. Among the isoflavones tested, 6-hydroxydaidzein (2) was the strongest scavenger of both ABTS(.+) and DPPH(.) radicals with SC50 values of 11.3 ± 0.3 and 9.4 ± 0.1 μM, respectively. Texasin (20) exhibited the most potent inhibition of mushroom tyrosinase (IC50 14.9 ± 4.5 μM), whereas retusin (17) showed the most efficient inhibition both of cellular melanin formation and antityrosinase activity in B16F10 melanocytes, respectively. In summary, both retusin (17) and texasin (20) exhibited potent free-radical-scavenging capacities as well as efficient inhibition of cellular melanogenesis, suggesting that they are valuable hit compounds with potential for advanced cosmeceutical development. Copyright © 2015 Verlag Helvetica Chimica Acta AG, Zürich.

  2. Preparation of Egg White Liquid Hydrolysate (ELH) and Its Radical-Scavenging Activity

    Science.gov (United States)

    Noh, Dong Ouk; Suh, Hyung Joo

    2015-01-01

    In the present study, an optimum protease was selected to hydrolyze the egg white liquid protein for the antioxidant peptides. Alcalase treatment yielded the highest amount of α-amino groups (15.27 mg/mL), while the control (no enzymatic hydrolysis) showed the lowest amount of α-amino groups (1.53 mg/mL). Alcalase also gave the highest degree of hydrolysis (DH) value (43.2%) and was more efficient for egg white liquid hydrolysis than the other enzymes. The Alcalase hydrolysate had the highest radical-scavenging activity (82.5%) at a concentration of 5.0 mg/mL. The conditions for enzymatic hydrolysis of egg white liquid with Alcalase were selected as substrate : water ratio of 2:1. Five percent Alacalse treatment did not show significant (P>0.05) increases of DH and α-amino nitrogen content after 24 h-hydrolysis. Thirty two hour-hydrolysis with 5% Alcalase is sufficient to make antioxidative egg white liquid hydrolysate from egg white liquid. DPPH and ABTS radical-scavenging activities were significantly (P<0.05) higher after enzymatic digestion. These results suggest that active peptides released from egg-white protein are effective radical-scavengers. Thus, this approach may be useful for the preparation of potent antioxidant products. PMID:26451355

  3. Phytochemical composition and radical scavenging activities of watermelon (Citrullus lanatus seed constituents

    Directory of Open Access Journals (Sweden)

    O. L. Otutu

    2016-01-01

    Full Text Available It is a known fact that antioxidant phytochemicals in foods have many health benefits including prevention of various diseases associated with oxidative stress such as cancer, cardiovascular disease, neuro-degeneration and diabetes. Watermelon seed constituents (whole meal, shelled and shells flours were evaluated for phytochemical components and in vitro antioxidant activity to determine the potential practical applications in food and other related areas. Antioxidant activity was investigated by measuring its DPPH (2,2-diphenyl-2-picryl hydrazyl and ABTS (2, 2’-azinobis-3-ethylbenzothiozoline- 6-sulphonic acid radical scavenging ability as well as FRAP method (ferric reducing power. Quantitative estimation of the constituents showed cardiac glycosides (9.94-14.35 mg/g and saponins (11.62-32.48 mg/g as the most concentrated phytochemicals in the constituents, while alkaloids (47.2-95.8 mg/g, total phenol (5.63-8.40 mg GAE/g, flavonoids 3.51-7.76 mg QE/g. A positive radical scavenging ability of the constituents against ABTS and DPPH free radicals ranged from 0.02 to 0.04 mg Trolox equivalent /g seed flour and 39.89 to 61.11 mg ascorbic acid equivalent /g seed flour respectively. There was a considerable ferric reducing power and higher activity was observed in whole meal than shelled seeds and shells. The significant antioxidant capacities of the seed constituents underline the potential source of natural antioxidants and bioactive compounds for therapeutic purposes.

  4. Graphdiyne Nanoparticles with High Free Radical Scavenging Activity for Radiation Protection.

    Science.gov (United States)

    Xie, Jiani; Wang, Ning; Dong, Xinghua; Wang, Chengyan; Du, Zhen; Mei, Linqiang; Yong, Yuan; Huang, Changshui; Li, Yuliang; Gu, Zhanjun; Zhao, Yuliang

    2018-03-06

    Numerous carbon networks materials comprised of benzene moieties, such as graphene and fullerene, have held great fascination for radioprotection because of their acknowledged good biocompatibility and strong free radical scavenging activity derived from their delocalized π-conjugated structure. Recently, graphdiyne, a new emerging carbon network material consisting of a unique chemical structure of benzene and acetylenic moieties, has gradually attracted attention in many research fields. Encouraged by its unique structure with strong conjugated π-system and highly reactive diacetylenic linkages, graphdiyne might have free radical activity and can thus be used as a radioprotector, which has not been investigated so far. Herein, for the first time, we synthesized bovine serum albumin (BSA)-modified graphdiyne nanoparticles (graphdiyne-BSA NPs) to evaluate their free radical scavenging ability and investigate their application for radioprotection both in cell and animal models. In vitro studies indicated that the graphdiyne-BSA NPs could effectively eliminate the free-radicals, decrease radiation-induced DNA damage in cells, and improve the viability of cells under ionizing radiation. In vivo experiments showed that the graphdiyne-BSA NPs could protect the bone marrow DNA of mice from radiation-induced damage and make the superoxide dismutase (SOD) and malondialdehyde (MDA) (two kinds of vital indicators of radiation-induced injury) recover back to normal levels. Furthermore, the good biocompatibility and negligible systemically toxicity responses of the graphdiyne-BSA NPs to mice were verified. All these results manifest the good biosafety and radioprotection activity of graphdiyne-BSA NPs to normal tissues. Therefore, our studies not only provide a new radiation protection platform based on graphdiyne for protecting normal tissues from radiation-caused injury but also provide a promising direction for the application of graphdiyne in the biomedicine field.

  5. Activity Of The Moderate And Radical Islamic Organizations In The European States

    Directory of Open Access Journals (Sweden)

    Nina V. Volodina

    2014-12-01

    Full Text Available In the present article author examines various aspects of Islamic organizations functioning in modern European countries. In the world the dangerous situation due to the spread of radical Islamic views, this is directly related to safety arose. Author researches some aspects of Islamic organizations in Europe functioning and their division into "moderate" and "radical". Author notes that the concept of "moderate Islam" is actively used in the western countries. In the article it is emphasized that supporters of such division believe that it is the "moderate Islamists" may help deal with the terrorist threat. Author gives definition of "religious extremism" and analyzes activities of Islamic organizations in Germany and France, as well as other European countries at the present stage of their development. In the process of study author pays enough attention to the notion of "spreading radicalism within the law", analyze existing legal acts. In the article problems of financing extremist organizations is pointed out and the need to create a set of joint measures to counter extremism and terrorism by Russian Federation and European countries, further improvement of law-enforcement is identified.

  6. Reaction of misonidazole with DNA radicals and its effect on the template activity of DNA

    International Nuclear Information System (INIS)

    Endoh, Daiji; Kuwabara, Mikinori; Sato, Fumiaki; Yoshii, Giichi.

    1985-01-01

    After calf thymus DNA was gamma-irradiated in the solid state in vacuo and subsequently dissolved in aqueous solution containing misonidazole (3 mM) under hypoxic condition, the frequency of single-strand breaks and alkali-labile sites in DNA and the amount of misonidazole bound to DNA were measured. The presence of misonidazole converted the precursor radicals, which otherwise results in single-strand breaks, to alkali-labile sites, and the amount of alkali-labile sites increased linearly with increasing radiation dose. The amount of misonidazole bound to DNA also increased linearly with increasing radiation dose. The biological meaning of the changes in the frequency of single-strand breaks and alkali-labile sites by the reaction of misonidazole with DNA radicals and of binding misonidazole with DNA was examined using a model system to measure the template activity of DNA for RNA synthesis in vitro. The conversion of DNA radicals to alkali-labile sites protected the radiation-induced decrease in the template activity of DNA, while the adduct formation of misonidazole had no effect on it. (author)

  7. Antioxidant activity of melatonin and glutathione interacting with hydroxyl- and superoxide anion radicals

    Directory of Open Access Journals (Sweden)

    T. Y. Kuznetsova

    2017-12-01

    Full Text Available Based on the analysis of the results obtained by quantum chemical modeling of interaction between reduced glutathione (GSH and melatonin (MLT molecules with oxygen radicals (•OH and • OOˉ it was found that this interaction occured following the acid-base mechanism, where MLT and GSH acted as a base in respect of •OH, and as acid in respect of •OOˉ. We have carried out the correlation of the results of quantum chemical calculations (density redistribution, energetic characteristics under the interaction of MLT and GSH molecules with •OH and •OOˉ in changing macroscopic properties of the process of electroreduction of free oxygen radicals in the presence of antioxidants (potential and maximal current wave reduction waves. This was a direct experimental macroscale evidence of the results of theoretical modeling at the nanoscale level that pointed to a marked antioxidant activity of glutathione compared with melatonin.

  8. LC/PDA/ESI-MS Profiling and Radical Scavenging Activity of Anthocyanins in Various Berries

    Directory of Open Access Journals (Sweden)

    Jun-ichiro Nakajima

    2004-01-01

    Full Text Available Anthocyanin extracts of two blueberries, Vaccinium myrtillus (bilberry and Vaccinium ashei (rabbiteye blueberry, and of three other berries, Ribes nigrum (black currant, Aronia melanocarpa (chokeberry, and Sambucus nigra (elderberry, were analyzed by high-performance liquid chromatography coupled with photodiode array detection and electrospray ionization - mass spectrometry (LC/PDA/ESI-MS. Both bilberry and rabbiteye blueberry contained 15 identical anthocyanins with different distribution patterns. Black currant, chokeberry, and elderberry contained 6, 4, and 4 kinds of anthocyanins, respectively. The radical scavenging activities of these berry extracts were analyzed by using 2,2-diphenyl-1-picrylhydrazyl (DPPH. All these extracts showed potent antiradical activities.

  9. Surface functionalisation of polypyrrole films using UV light induced radical activation

    International Nuclear Information System (INIS)

    Lisboa, P.; Gilliland, D.; Ceccone, G.; Valsesia, A.; Rossi, F.

    2006-01-01

    Electrochemically deposited polypyrrole (PPy) films were functionalised with amine or carboxylic function. The functionalisation was done by grafting allylamine or acrylic acid (AAc) using UV light radical activation. The active groups of the surface were quantified by X-ray photoelectron spectroscopy (XPS) after chemical derivatisation with trifluoroethanol (TFE) or 4-trifluoromethylbenzaldehyde (TFBA), respectively. Grafting with AAc completely covered the PPy film introducing high levels of carboxylic function. In the case of allylamine grafting, a saturation point at low amine carbon level was achieved. Further characterisation of the surfaces was done by time of flight secondary ion mass spectroscopy (TOF-SIMS), atomic force microscope (AFM) and scanning electron microscope (SEM)

  10. VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells

    International Nuclear Information System (INIS)

    Garcia-Roman, Jonathan; Ibarra-Sanchez, Alfredo; Lamas, Monica; Gonzalez Espinosa, Claudia

    2010-01-01

    Research highlights: → Bone marrow-derived mast cells (BMMCs) secrete functional VEGF but do not degranulate after Cobalt chloride-induced hypoxia. → CoCl 2 -induced VEGF secretion in mast cells occurs by a Ca 2+ -insensitive but brefeldin A and Tetanus toxin-sensitive mechanism. → Trolox and N-acetylcysteine inhibit hypoxia-induced VEGF secretion but only Trolox inhibits FcεRI-dependent anaphylactic degranulation in mast cells. → Src family kinase Fyn activation after free radical production is necessary for hypoxia-induced VEGF secretion in mast cells. -- Abstract: Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl 2 ) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl 2 promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl 2 -induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl 2 -induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl 2 in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals-dependent Fyn kinase activation.

  11. Extraction method for high free radical scavenging activity of Siamese neem tree flowers

    Directory of Open Access Journals (Sweden)

    Worarat Chaisawangwong

    2009-10-01

    Full Text Available Siamese neem tree (Azadirachta indica A. Juss. var. siamensis Valeton is a medicinal plant found in Thailand. Youngleaves and young flowers of this plant are commonly consumed as a bitter tonic vegetable. The flowers are also used fortreatment of fever. The flower extract has been reported to exhibit in vitro free radical scavenging activity and can inhibitlipid peroxidation of bronchogenic cancer cell line. Active compounds in the flowers are flavonoids such as rutin andquercetin. The content of these compounds in the crude extract depends on the method of extraction. Therefore, the appropriateextraction method promoting high yield of total flavonoids and high free radical scavenging activity was investigated inthis study. Six different extraction methods, i.e. maceration, percolation, decoction, soxhlet extraction, ultrasonic extraction(UE, and microwave assisted extraction (MA were carried out for extracting dried powder of Siamese neem tree young flowers. The solvent used for maceration, percolation, and soxhlet extraction was 50% ethanol, while distilled water was used for decoction and MA, and both solvents were used for UE. The content of crude extract, free radical scavenging activity, and total flavonoids content of each extract were investigated and compared. Comparing the various extraction methods, decoction provided an extract containing a high amount of total flavonoids (17.54 mgRE/g extract and promoting the highest scavenging activity at EC50 11.36 g/ml. Decoction is also simple, cheap, and convenient and could be used in developing countries. Thus, it should be the recommended extraction method for the flowers of Siamese neem tree for furtherdevelopment of antioxidant pharmaceutical preparations.

  12. Efficient peroxydisulfate activation process not relying on sulfate radical generation for water pollutant degradation

    KAUST Repository

    Zhang, Tao

    2014-05-20

    Peroxydisulfate (PDS) is an appealing oxidant for contaminated groundwater and toxic industrial wastewaters. Activation of PDS is necessary for application because of its low reactivity. Present activation processes always generate sulfate radicals as actual oxidants which unselectively oxidize organics and halide anions reducing oxidation capacity of PDS and producing toxic halogenated products. Here we report that copper oxide (CuO) can efficiently activate PDS under mild conditions without producing sulfate radicals. The PDS/CuO coupled process is most efficient at neutral pH for decomposing a model compound, 2,4-dichlorophenol (2,4-DCP). In a continuous-flow reaction with an empty-bed contact time of 0.55 min, over 90% of 2,4-DCP (initially 20 μM) and 90% of adsorbable organic chlorine (AOCl) can be removed at the PDS/2,4-DCP molar ratio of 1 and 4, respectively. Based on kinetic study and surface characterization, PDS is proposed to be first activated by CuO through outer-sphere interaction, the rate-limiting step, followed by a rapid reaction with 2,4-DCP present in the solution. In the presence of ubiquitous chloride ions in groundwater/industrial wastewater, the PDS/CuO oxidation shows significant advantages over sulfate radical oxidation by achieving much higher 2,4-DCP degradation capacity and avoiding the formation of highly chlorinated degradation products. This work provides a new way of PDS activation for contaminant removal. © 2014 American Chemical Society.

  13. VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Roman, Jonathan; Ibarra-Sanchez, Alfredo; Lamas, Monica [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico); Gonzalez Espinosa, Claudia, E-mail: cgonzal@cinvestav.mx [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico)

    2010-10-15

    Research highlights: {yields} Bone marrow-derived mast cells (BMMCs) secrete functional VEGF but do not degranulate after Cobalt chloride-induced hypoxia. {yields} CoCl{sub 2}-induced VEGF secretion in mast cells occurs by a Ca{sup 2+}-insensitive but brefeldin A and Tetanus toxin-sensitive mechanism. {yields} Trolox and N-acetylcysteine inhibit hypoxia-induced VEGF secretion but only Trolox inhibits Fc{epsilon}RI-dependent anaphylactic degranulation in mast cells. {yields} Src family kinase Fyn activation after free radical production is necessary for hypoxia-induced VEGF secretion in mast cells. -- Abstract: Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl{sub 2}) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl{sub 2} promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl{sub 2}-induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl{sub 2}-induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl{sub 2} in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals

  14. Highly functionalized piperidines: Free radical scavenging, anticancer activity, DNA interaction and correlation with biological activity

    Directory of Open Access Journals (Sweden)

    Suvankar Das

    2018-01-01

    Full Text Available Twenty-five piperidines were studied as potential radical scavengers and antitumor agents. Quantitative interaction of compounds with ctDNA using spectroscopic techniques was also evaluated. Our results demonstrate that the evaluated piperidines possesses different abilities to scavenge the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH and the anion radical superoxide (·O2−. The piperidine 19 was the most potent radical DPPH scavenger, while the most effective to ·O2− scavenger was piperidine 10. In general, U251, MCF7, NCI/ADR-RES, NCI-H460 and HT29 cells were least sensitive to the tested compounds and all compounds were considerably more toxic to the studied cancer cell lines than to the normal cell line HaCaT. The binding mode of the compounds and ctDNA was preferably via intercalation. In addition, these results were confirmed based on theoretical studies. Finally, a linear and exponential correlation between interaction constant (Kb and GI50 for several human cancer cell was observed.

  15. The Synthesis and Evaluation of Novel Hydroxyl Substituted Chalcone Analogs with in Vitro Anti-Free Radicals Pharmacological Activity and in Vivo Anti-Oxidation Activity in a Free Radical-Injury Alzheimer’s Model

    Directory of Open Access Journals (Sweden)

    Ying Pan

    2013-01-01

    Full Text Available Alzheimer’s disease (AD pathogenesis involves an imbalance between free radical formation and destruction. In order to obtain a novel preclinical anti-AD drug candidate, we synthesized a series of novel hydroxyl chalcone analogs which possessed anti-free radical activity, and screened their effects on scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH and OH free radicals in vitro. Compound C7, 4,2'-dihydroxy-3,5-dimethoxychalcone was found to have potent activity in these anti-free radical activity tests. Further research revealed that C7 could elevate glutathione peroxidase (GSH-PX and super oxide dismutase (SOD levels and lower malonaldehyde (MDA level in vivo in the Alzheimer’s model. The indication of C7’s effect on AD needs further study.

  16. Modulation of TRP channels by resveratrol and other stilbenoids

    Directory of Open Access Journals (Sweden)

    Yu Lina

    2013-02-01

    Full Text Available Abstract Background Resveratrol (3,5,4’ - trihydroxy-trans-stilbene, a widely distributed natural stilbenoid, was proposed to account for the unique effects of red wine on life span and health. It has been reported to possess various biological and pharmacological activities, such as anti-oxidant, anti-inflammatory, and anti-carcinogenic effects. Here, using whole-cell patch-clamp techniques and behavioral analyses, we investigated whether resveratrol and other stilbenoids can modulate TRP channels in sensory neurons in vitro, and have analgesic effects in vivo. Results We found that resveratrol dose-dependently suppressed the allyl isothiocyanate (AITC-induced currents (IAITC in HEK293 cells that express TRPA1, as well as in rat dorsal root ganglion (DRG neurons. Instead, pinosylvin methyl ether (PME, another derivate of stilbene which has a similar structure to resveratrol, dose-dependently blocked the capsaicin-induced currents (ICAP in HEK293 cells that express TRPV1 as well as in DRG neurons. Interestingly, resveratrol had no inhibitory effect on the ICAP, and PME had no effect on the IAITC. Otherwise, trans-stilbene showed no any effect on IAITC or ICAP. The concentration response curve of AITC showed that resveratrol inhibited the action of TRPA1 not by changing the EC50, but by suppressing the AITC-induced maximum response. By contrast, the inhibition of TRPV1 by PME did not change the capsaicin-induced maximum response but did cause a right shift of the EC50. Moreover, pre-administration of resveratrol suppressed intraplantar injections of AITC-evoked nocifensive behaviors, as well as that PME suppressed capsaicin-evoked one. Conclusions These data suggest that resveratrol and other stilbenoids may have an inhibitory effect on TRP channels. In addition, these stilbenoids modulate TRP channel activity in different ways.

  17. Radical transfer between proteins: role of tyrosine, tryptophan and protein peroxyl radicals

    International Nuclear Information System (INIS)

    Irwin, J.A.; Ostdal, H.; Davies, M.J.

    1998-01-01

    Reaction of the Fe(III) forms of the heme proteins myoglobin (Mb) and horseradish peroxidase (HRP) with H 2 O 2 gives rise to high-oxidation-state heme-derived species which can be described as a Fe(IV)-oxo porphyrin radical-cation ('Compound 1'). In the case of Mb, the Fe(IV)-oxo porphyrin radical-cation undergoes rapid electron transfer with the surrounding protein to give protein (globin)-derived radicals and an Fe(lV)-oxo species ('Compound 2'). The globin-derived radicals have been shown to be located at two (or more) sites: Tyr-103 or Trp-14, with the latter radical known to react with oxygen to give a Trp-derived peroxyl radical (Mb-Trp-OO*). With HRP, the Fe(lV)-oxo porphyrin radical-cation carries out two successive one-electron oxidation reactions at the exposed heme edge to give firstly 'Compound 2' [the Fe(lV)oxo species] and then the resting Fe(III) state of the enzyme. n this study we have investigated whether the Trp-14 peroxyl radical from Mb and the Compound 1 and 2 species from HRP (in the absence and presence of free Tyr) can oxidise amino acids, peptides and proteins. Such reactions constitute intermolecular protein-to-protein radical transfer reactions and hence protein chain-oxidation. We have also examined whether these oxidants react with antioxidants. Reaction of these heme-protein derived oxidants with amino acids, proteins and antioxidants has been carried out at room temperature for defined periods of time before freeze-quenching to 77K to halt reaction. The radical species present in the reaction system at the time of freezing were subsequently examined by EPR spectroscopy at 77K. Three free amino acids, Tyr, Trp and Cys (with Cys the least efficient) have been shown to react rapidly with Mb-Trp-OO*, as evidenced by the loss of the characteristic EPR features of Mb-Trp-OO* on inclusion of increasing concentrations of the amino acids. All other amino acids are much less reactive. Evidence has also been obtained for (inefficient) hydrogen

  18. Study On DPPH Free Radical - Scavenging Activity Of Antioxidant Compounds In Plants Composing BIN-5 Biological Active Preparation

    Directory of Open Access Journals (Sweden)

    Purevjav Urjintseren

    2015-08-01

    Full Text Available Recently there has been common trend among people to refuse from food and medications produced via synthetic method but try to consume natural products as much as possible instead. In this regard wild berries and medicinal plants are considered to be highly essential for human health as these kinds of plants serve as rich sources of biological active substances-phenol compounds. As a result of conducting research on source and spread of herbs which are commonly used as anti-diabetic medication we have developed a technological method to extract preparations from medicinal herbs such as Peony Paeonia lactiflora Pall Dandelion Taraxacum officinalis Wigg. Huckleberry Vaccinium myrtillus L Blueberry Vaccinium uliginosum L Cranberry Vaccinium vitisidaea L and Stinging nettles Urtica dioica accordingly studied chemical composition and antioxidant activity and conducted pharmacological study. With the use of Folin Denis amp Folin Ciocalteu reagent methodit was determined that the content of polyphenol compounds was 4.14-5.17 and 27.5 101.5mgml. The study was also aimed to investigate DPPH free radical-scavenging activity in connection with term temperature and concentration to identify the most rational technological procedure. As a result of study it was identified that free radical-scavenging activity of herbs selected for the study was generally estimated at 564.25-1750.00 mcgml whereas antioxidant activity of solvents with 2-10 mgml concentration was 417.20-1750.00 mcg ml respectively. This shows that such activity is dependent on concentration. However in temperature of 30 1000amp1057 degrees their activity has slowly been decreased by 1750 mcgml 476.7mcgml depending on temperature. Regarding the stinging nettles the activity was grown directly dependent from temperature. DPHH free radical-scavenging activity was gradually increased in 1-10 minutes but was relatively stable and active in 11-16 minutes.

  19. A thermodynamic framework for understanding temperature sensing by transient receptor potential (TRP) channels.

    Science.gov (United States)

    Clapham, David E; Miller, Christopher

    2011-12-06

    The exceptionally high temperature sensitivity of certain transient receptor potential (TRP) family ion channels is the molecular basis of hot and cold sensation in sensory neurons. The laws of thermodynamics dictate that opening of these specialized TRP channels must involve an unusually large conformational standard-state enthalpy, ΔH(o): positive ΔH(o) for heat-activated and negative ΔH(o) for cold-activated TRPs. However, the molecular source of such high-enthalpy changes has eluded neurobiologists and biophysicists. Here we offer a general, unifying mechanism for both hot and cold activation that recalls long-appreciated principles of protein folding. We suggest that TRP channel gating is accompanied by large changes in molar heat capacity, ΔC(P). This postulate, along with the laws of thermodynamics and independent of mechanistic detail, leads to the conclusion that hot- and cold-sensing TRPs operate by identical conformational changes.

  20. Photodynamically generated bovine serum albumin radicals

    DEFF Research Database (Denmark)

    Silvester, J A; Timmins, G S; Davies, Michael Jonathan

    1998-01-01

    Porphyrin-sensitized photoxidation of bovine serum albumin (BSA) results in oxidation of the protein at (at least) two different, specific sites: the Cys-34 residue giving rise to a thiyl radical (RS.); and one or both of the tryptophan residues (Trp-134 and Trp-214) resulting in the formation...... of tertiary carbon-centred radicals and disruption of the tryptophan ring system. In the case of porphyrins such as hematoporphyrin, which bind at specific sites on BSA, these species appear to arise via long-range transfer of damage within the protein structure, as the binding site is some distance from...... the ultimate site of radical formation. This transfer of damage is shown to depend on a number of factors including the conformation of the protein, the presence of blocking groups and pH. Alteration of the protein conformation results in radical formation at additional (or alternative) sites, as does blocking...

  1. Free Radical Scavenging Activity and Anthocyanin Profile of Cabernet Sauvignon Wines from the Balkan Region

    Directory of Open Access Journals (Sweden)

    Blaga Radovanović

    2010-06-01

    Full Text Available The present study is focused on anthocyanin derivatives characterizing the antioxidant activity of Cabernet Sauvignon wines produced from different vineyard regions in the Balkans. These bioactive compounds were quantified with a high performance liquid chromatography (HPLC-diode array detection (DAD method. The antiradical activity was estimated by the ability of the wine to scavenge the stable 2,2`-diphenyl-1-picrylhydrazyl free radical (DPPH·. The results show that the total anthocyanin content varied from 205.88 to 1940.28 mg/L, depending on agroclimatic factors and the enological practices of the corresponding vineyard region. The most prominent antocyanin in all investigated Cabernet Sauvignon wines was malvidin-3-O-monoglucoside, which accounted for 50.57% of total content, followed by its acetyl derivatives, 15.45%, and p-coumaryl derivatives 5.66%. The relationship between the anthocyanin derivatives and free radical scavenging activity is discussed. A high correlation between total anthocyanin content and DPPH· scavenging ability of tested wines was confirmed (r2 = 0.9619. The significant correlations were obtained between antiradical activity and the sum of 3-monoglucoside (r2 = 0.95594, the sum of 3-acetyl-3-glucoside (r2 = 0.9728 and the sum of p-coumaryl-3-glucoside (r2 = 0.8873 of wine samples. It can be concluded that, the anthocyanin composition can be used as biochemical marker for the authenticity of red grape cultivar and their corresponding single-cultivar wine.

  2. In Vitro Antimicrobial Bioassays, DPPH Radical Scavenging Activity, and FTIR Spectroscopy Analysis of Heliotropium bacciferum.

    Science.gov (United States)

    Ahmad, Sohail; AbdEl-Salam, Naser M; Ullah, Riaz

    2016-01-01

    The present study deals with the antimicrobial, antioxidant, and functional group analysis of Heliotropium bacciferum extracts. Disc diffusion susceptibility method was followed for antimicrobial assessment. Noteworthy antimicrobial activities were recorded by various plant extracts against antibiotic resistant microorganisms. Plant flower extracts antioxidant activity was investigated against 2, 2-diphenyl-1-picryl hydrazyl radical by ultraviolet spectrophotometer (517 nm). Plant extracts displayed noteworthy radical scavenging activities at all concentrations (25-225 μg/mL). Notable activities were recorded by crude, chloroform and ethyl acetate extracts up to 88.27% at 225 μg/mL concentration. Compounds functional groups were examined by Fourier transform infrared spectroscopic studies. Alkanes, alkenes, alkyl halides, amines, carboxylic acids, amides, esters, alcohols, phenols, nitrocompounds, and aromatic compounds were identified by FTIR analysis. Thin layer chromatography bioautography was carried out for all plant extracts. Different bands were separated by various solvent systems. The results of the current study justify the use of Heliotropium bacciferum in traditional remedial herbal medicines.

  3. In Vitro Antimicrobial Bioassays, DPPH Radical Scavenging Activity, and FTIR Spectroscopy Analysis of Heliotropium bacciferum

    Directory of Open Access Journals (Sweden)

    Sohail Ahmad

    2016-01-01

    Full Text Available The present study deals with the antimicrobial, antioxidant, and functional group analysis of Heliotropium bacciferum extracts. Disc diffusion susceptibility method was followed for antimicrobial assessment. Noteworthy antimicrobial activities were recorded by various plant extracts against antibiotic resistant microorganisms. Plant flower extracts antioxidant activity was investigated against 2, 2-diphenyl-1-picryl hydrazyl radical by ultraviolet spectrophotometer (517 nm. Plant extracts displayed noteworthy radical scavenging activities at all concentrations (25–225 μg/mL. Notable activities were recorded by crude, chloroform and ethyl acetate extracts up to 88.27% at 225 μg/mL concentration. Compounds functional groups were examined by Fourier transform infrared spectroscopic studies. Alkanes, alkenes, alkyl halides, amines, carboxylic acids, amides, esters, alcohols, phenols, nitrocompounds, and aromatic compounds were identified by FTIR analysis. Thin layer chromatography bioautography was carried out for all plant extracts. Different bands were separated by various solvent systems. The results of the current study justify the use of Heliotropium bacciferum in traditional remedial herbal medicines.

  4. On the mechanism of activation of copper-catalyzed atom transfer radical polymerization

    International Nuclear Information System (INIS)

    Isse, Abdirisak Ahmed; Bortolamei, Nicola; De Paoli, Patrizia; Gennaro, Armando

    2013-01-01

    The mechanism of activation of atom transfer radical polymerization (ATRP) has been analyzed by investigating the kinetics of dissociative electron transfer (ET) to alkyl halides (RX) in acetonitrile. Using a series of alkyl halides, including both bromides and chlorides, the rate constants of ET (k ET ) to RX by electrogenerated aromatic radical anions (A· − ) acting as outer-sphere donors have been measured and analyzed according to the current theories of dissociative ET. This has shown that the kinetic data fit very well the “sticky” dissociative ET model with the formation of a weak adduct held together by electrostatic interactions. The rate constants of activation, k act , of some alkyl halides, namely chloroacetonitrile, methyl 2-bromopropionate and ethyl chloroacetate, by [Cu I L] + (L = tris(2-dimethylaminoethyl)amine, tris(2-pyridylmethyl)amine, 1,1,4,7,7-pentamethyldiethylenetriamine) have also been measured in the same experimental conditions. Comparisons of the measured k act values with those predicted assuming an outer-sphere ET for the complexes have shown that activation by Cu(I) is 7–10 orders of magnitude faster than required by outer-sphere ET. Therefore, the mechanism of RX activation by Cu(I) complexes used as catalysts in ATRP occurs by an inner-sphere ET or more appropriately by a halogen atom abstraction

  5. Evaluation of Free Radical Scavenging Activity in Ethanolic Extract from Promising Accessions of Curcuma aeruginosa RoxB.

    Directory of Open Access Journals (Sweden)

    Waras Nurcholis

    2017-11-01

    Full Text Available This study evaluated the free radical scavenging activity in ethanolic extracts from 20 accessions of Curcuma aeruginosa. The radical scavenging activity of the extract accessions was investigated with 2,2-diphenyl-1-picrylhydrazyl (DPPH radical. IC50 values for DPPH radical scavenging activity ranged from 89.81 to 505.65 µg mL-1. Based on IC50 values, twenty accessions of C. aeruginosa can be divided into three groups: strong (two accessions; moderate (seventeen accessions; and low (one accession of DPPH scavenger. Sukoharjo (SH and Muara Bungo (MB showed promising accessions for antioxidant potential, thus these accessions important to selection for future breeding program in pharmaceutical products.

  6. BAX and tumor suppressor TRP53 are important in regulating mutagenesis in spermatogenic cells in mice.

    Science.gov (United States)

    Xu, Guogang; Vogel, Kristine S; McMahan, C Alex; Herbert, Damon C; Walter, Christi A

    2010-12-01

    During the first wave of spermatogenesis, and in response to ionizing radiation, elevated mutant frequencies are reduced to a low level by unidentified mechanisms. Apoptosis is occurring in the same time frame that the mutant frequency declines. We examined the role of apoptosis in regulating mutant frequency during spermatogenesis. Apoptosis and mutant frequencies were determined in spermatogenic cells obtained from Bax-null or Trp53-null mice. The results showed that spermatogenic lineage apoptosis was markedly decreased in Bax-null mice and was accompanied by a significantly increased spontaneous mutant frequency in seminiferous tubule cells compared to that of wild-type mice. Apoptosis profiles in the seminiferous tubules for Trp53-null were similar to control mice. Spontaneous mutant frequencies in pachytene spermatocytes and in round spermatids from Trp53-null mice were not significantly different from those of wild-type mice. However, epididymal spermatozoa from Trp53-null mice displayed a greater spontaneous mutant frequency compared to that from wild-type mice. A greater proportion of spontaneous transversions and a greater proportion of insertions/deletions 15 days after ionizing radiation were observed in Trp53-null mice compared to wild-type mice. Base excision repair activity in mixed germ cell nuclear extracts prepared from Trp53-null mice was significantly lower than that for wild-type controls. These data indicate that BAX-mediated apoptosis plays a significant role in regulating spontaneous mutagenesis in seminiferous tubule cells obtained from neonatal mice, whereas tumor suppressor TRP53 plays a significant role in regulating spontaneous mutagenesis between postmeiotic round spermatid and epididymal spermatozoon stages of spermiogenesis.

  7. Comparative antihemolytic and radical scavenging activities of strawberry tree (Arbutus unedo L.) leaf and fruit.

    Science.gov (United States)

    Mendes, Lídia; de Freitas, Victor; Baptista, Paula; Carvalho, Márcia

    2011-09-01

    The present study reports the antioxidant properties of Arbutus unedo L. leaf and fruit extracts using different in vitro assays including (i) reducing power, (ii) scavenging effect on DPPH free radicals, and (iii) inhibitory effect on AAPH-induced hemolysis and lipid peroxidation in human erythrocytes. All assays demonstrated antioxidant efficiency for A. unedo L. aqueous extracts, being consistently higher in the leaf. EC(50) values for reducing power and DPPH radical scavenging activities were, respectively, 0.318 ± 0.007 and 0.087 ± 0.007 mg/mL for leaf, and 2.894 ± 0.049 and 0.790 ± 0.016 mg/mL for fruit extracts. Under the oxidative action of AAPH, A. unedo leaf and fruit extracts protected the erythrocyte membrane from hemolysis (IC(50) of 0.062 ± 0.002 and 0.430 ± 0.091 mg/mL, respectively) and decreased the levels of malondialdehyde, a breakdown product of lipid peroxidation (IC(50) of 0.075 ± 0.014 and 0.732 ± 0.452 mg/mL, respectively). In accordance with antioxidant activity, phenolic content was found to be significantly higher in leaf extract. To our knowledge, this is the first time that the antioxidant activity of A. unedo species is evaluated using human biological membranes. Overall, our results suggest that A. unedo leaves are a promising source of natural antioxidants with potential application in diseases mediated by free radicals. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Phytochemical screening, free radical scavenging, antioxidant activity and phenolic content of Dodonaea viscosa

    Directory of Open Access Journals (Sweden)

    Riaz Tauheeda

    2012-01-01

    Full Text Available The purpose of this study was to evaluate the antioxidant potential of Dodonaea viscosa Jacq. Methanolic extract of the plant was dissolved in distilled water and partitioned with n-hexane, chloroform, ethyl acetate and nbutanol sequentially. Phytochemical screening showed presence of phenolics, flavonoides and cardiac glycosides in large amount in chloroform, ethyl acetate and n-butanol fraction. The antioxidant potential of all these fractions and remaining aqueous fraction was evaluated by four methods: 1,1-Diphenyl-2-picrylhydrazyl (DPPH free radical scavenging activity, total antioxidant activity, Ferric Reducing Antioxidant Power (FRAP assay and ferric thiocyanate assay along with determination of their total phenolics. The results revealed that ethyl acetate soluble fraction exhibited highest percent inhibition of DPPH radical as compared to other fractions. It showed 81.14 ± 1.38% inhibition of DPPH radical at a concentration of 60 μg/ml. The IC50 of this fraction was found to be 33.95 ± 0.58 μg/ml, relative to butylated hydroxytoluene (BHT, having IC50 of 12.54 ± 0.89 μg/mL. It also showed highest FRAP value (380.53 ± 0.74 μM of trolox equivalents as well as highest total phenolic contents (208.58 ± 1.83 GAE μg/g and highest value of inhibition of lipid peroxidation (58.11 ± 1.49% at concentration of 500 μg/ml as compared to the other studied fractions. The chloroform fraction showed highest total antioxidant activity i.e.1.078 ± 0.59 (eq. to BHT.

  9. Antioxidant activity of the giant jellyfish Nemopilema nomurai measured by the oxygen radical absorbance capacity and hydroxyl radical averting capacity methods.

    Science.gov (United States)

    Harada, Kazuki; Maeda, Toshimichi; Hasegawa, Yoshiro; Tokunaga, Takushi; Ogawa, Shinya; Fukuda, Kyoko; Nagatsuka, Norie; Nagao, Keiko; Ueno, Shunshiro

    2011-01-01

    The giant jellyfish Nemopilema nomurai (reaching sizes of up to 2 m diameter and 150 kg), which forms dense blooms, has caused extensive damage to fisheries by overloading trawl nets, while its toxic nematocysts cause dermatological symptoms. Giant jellyfish are currently discarded on the grounds of pest control. However, the giant jellyfish is considered to be edible and is part of Chinese cuisine. Therefore, we investigated whether any benefits for human health may be derived from consumption of the jellyfish in order to formulate medicated diets. Antioxidant activity of Nemopilema nomurai was measured using the oxygen radical absorbance capacity (ORAC) and hydroxyl radical averting capacity (HORAC) methods. Based on the results, the ORAC value of the giant jellyfish freeze-dried sample was 541 µmol trolox equivalent (TE)/100 g and the HORAC value was 3,687 µmol gallic acid equivalent (GAE)/100 g. On the other hand, the IC50 value of hydroxyl radical scavenging activity measured by using the electron spin resonance method was 3.3%. In conclusion, the results suggest that the freeze-dried powder of the giant jellyfish Nemopilema nomurai is a potentially beneficial food for humans.

  10. Dihydronaflavonols from the leaves of Derris urucu (Leguminosae): structural elucidation and DPPH radical-scavenging activity

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, Livia T.; Silva, Geilson A. da; Ferreira, Malisson; Silva, Milton N. da; Santos, Alberdan S.; Arruda, Alberto C.; Guilhon, Gisele M.S.P.; Santos, Lourivaldo S.; Arruda, Mara Silvia P. [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Inst. de Ciencias Exatas e Naturais. Programa de Pos-Graduacao em Quimica], e-mail: mspa@ufpa.br; Borges, Rosilvaldo dos Santos [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Fac. de Farmacia. Inst. de Ciencias

    2009-07-01

    Derris urucu is an Amazonian plant with insecticide and ichthyotoxic properties. Studies with this species show the presence of flavonoids, mainly rotenoids, as well as stilbenes. The ethanol extract of the leaves of Derris urucu (Leguminosae) afforded three new dihydroflavonols named urucuol A (1), B (2) and C (3), and the dihydroflavonol isotirumalin (4). Their structures were elucidated by extensive analysis of 1D and 2D NMR, UV and IR spectra and MS data and comparison with literature data. The isolated compounds (1-4) were evaluated for DPPH radical scavenging activity and showed a relatively lower antioxidant ability compared to the commercial antioxidant trans-resveratrol. (author)

  11. Theoretical insights on the antioxidant activity of edaravone free radical scavengers derivatives

    Science.gov (United States)

    Cerón-Carrasco, José P.; Roy, Hélène M.; Cerezo, Javier; Jacquemin, Denis; Laurent, Adèle D.

    2014-04-01

    The prediction of antioxidant properties is not straightforward due to the complexity of the in vivo systems. Here, we use theoretical descriptors, including the potential of ionization, the electrodonating power and the spin density distribution, to characterize the antioxidant capacity of edaravone (EDV) derivatives. Our computations reveal the relationship between these parameters and their potential bioactivity as free radical scavengers. We conclude that more efficient antioxidants could be synthesized by tuning the R1 and R2 positions of the EDV structure, rather than modifying the R3 group. Such modifications might improve the antioxidant activity in neutral and deprotonated forms.

  12. Free radical-scavenging capacity, antioxidant activity and phenolic content of Pouzolzia zeylanica

    Directory of Open Access Journals (Sweden)

    PEIYUAN LI

    2011-05-01

    Full Text Available Pouzolzia zeylanica was extracted with different solvents (acetone, ethyl acetate and petroleum ether, using different protocols (cold-extraction and Soxhlet extraction. To evaluate the antiradical and antioxidant abilities of the extracts, four in vitro test systems were employed, i.e., DPPH, ABTS and hydroxyl radical scavenging assays and a reducing power assay. All extracts exhibited outstanding antioxidant activities that were superior to that of butylated hydroxytoluene. The ethyl acetate extracts exhibited the most significant antioxidant activities, and cold-extraction under stirring seemed to be the more efficacious method for acquiring the predominant antioxidants. Furthermore, the antioxidant activities and total phenolic (TP content of different extracts followed the same order, i.e., there is a good correlation between antioxidant activities and TP content. The results showed that these extracts, especially the ethyl acetate extracts, could be considered as natural antioxidants and may be useful for curing diseases arising from oxidative deterioration.

  13. Scavenging performance and antioxidant activity of γ-alumina nanoparticles towards DPPH free radical: Spectroscopic and DFT-D studies.

    Science.gov (United States)

    Zamani, Mehdi; Moradi Delfani, Ali; Jabbari, Morteza

    2018-05-03

    The radical scavenging performance and antioxidant activity of γ-alumina nanoparticles towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical were investigated by spectroscopic and computational methods. The radical scavenging ability of γ-alumina nanoparticles in the media with different polarity (i.e. i-propanol and n-hexane) was evaluated by measuring the DPPH absorbance in UV-Vis absorption spectra. The structure and morphology of γ-alumina nanoparticles before and after adsorption of DPPH were studied using XRD, FT-IR and UV-Vis spectroscopic techniques. The adsorption of DPPH free radical on the clean and hydrated γ-alumina (1 1 0) surface was examined by dispersion corrected density functional theory (DFT-D) and natural bond orbital (NBO) calculations. Also, time-dependent density functional theory (TD-DFT) was used to predict the absorption spectra. The adsorption was occurred through the interaction of radical nitrogen N and NO 2 groups of DPPH with the acidic and basic sites of γ-alumina surface. The high potential for the adsorption of DPPH radical on γ-alumina nanoparticles was investigated. Interaction of DPPH with Brønsted and Lewis acidic sites of γ-alumina was more favored than Brønsted basic sites. The following order for the adsorption of DPPH over the different active sites of γ-alumina was predicted: Brønsted base free radicals. Copyright © 2018. Published by Elsevier B.V.

  14. Synthesis, Characterization, Antimicrobial Screening and Free-Radical Scavenging Activity of Some Novel Substituted Pyrazoles

    Directory of Open Access Journals (Sweden)

    Nagwa Mohamed Mahrous Hamada

    2015-06-01

    Full Text Available The present work deals with the synthesis of acetoxysulfonamide pyrazole derivatives, substituted 4,5-dihydropyrazole-1-carbothioamide and 4,5-dihydropyrazole-1-isonicotinoyl derivatives starting from substituted vanillin chalcones. Acetoxysulfonamide pyrazole derivatives were prepared from the reaction of chalcones with p-sulfamylphenylhydrazine followed by treatment with acetic anhydride. At the same time 4,5-dihydropyrazole-1-carbothioamide and 4,5-dihydropyrazole-1-isonicotinoyl derivatives were prepared from the reaction of chalcones with either thiosemicarbazide or isonicotinic acid hydrazide, respectively. The synthesized compounds were structurally characterized on the basis of IR, 1H-NMR, 13C-NMR spectral data and microanalyses. All of the newly isolated compounds were tested for their antimicrobial activities. The antimicrobial screening using the agar well-diffusion method revealed that the chloro derivatives are the most active ones. Moreover, the antioxidant and anti-inflammatory activity of these chloro derivatives are also studied using the DPPH radical scavenging and NO radical scavenging methods, respectively.

  15. Indoline Amide Glucosides from Portulaca oleracea: Isolation, Structure, and DPPH Radical Scavenging Activity.

    Science.gov (United States)

    Jiao, Ze-Zhao; Yue, Su; Sun, Hong-Xiang; Jin, Tian-Yun; Wang, Hai-Na; Zhu, Rong-Xiu; Xiang, Lan

    2015-11-25

    A polyamide column chromatography method using an aqueous ammonia mobile phase was developed for large-scale accumulation of water-soluble indoline amide glucosides from a medicinal plant, Portulaca oleracea. Ten new [oleraceins H, I, K, L, N, O, P, Q, R, S (1-10)] and four known [oleraceins A-D (11-14)] indoline amide glucosides were further purified and structurally characterized by various chromatographic and spectroscopic methods. The DPPH radical scavenging activities of oleraceins K (5) and L (6), with EC50 values of 15.30 and 16.13 μM, respectively, were twice that of a natural antioxidant, vitamin C; the EC50 values of the 12 other indoline amides, which ranged from 29.05 to 43.52 μM, were similar to that of vitamin C. Structure-activity relationships indicated that the DPPH radical scavenging activities of these indoline amides correlate with the numbers and positions of the phenolic hydroxy groups.

  16. Intracellular ROS protection efficiency and free radical-scavenging activity of curcumin.

    Directory of Open Access Journals (Sweden)

    Abolfazl Barzegar

    Full Text Available Curcumin has many pharmaceutical applications, many of which arise from its potent antioxidant properties. The present research examined the antioxidant activities of curcumin in polar solvents by a comparative study using ESR, reduction of ferric iron in aqueous medium and intracellular ROS/toxicity assays. ESR data indicated that the steric hindrance among adjacent big size groups within a galvinoxyl molecule limited the curcumin to scavenge galvinoxyl radicals effectively, while curcumin showed a powerful capacity for scavenging intracellular smaller oxidative molecules such as H₂O₂, HO•, ROO•. Cell viability and ROS assays demonstrated that curcumin was able to penetrate into the polar medium inside the cells and to protect them against the highly toxic and lethal effects of cumene hydroperoxide. Curcumin also showed good electron-transfer capability, with greater activity than trolox in aqueous solution. Curcumin can readily transfer electron or easily donate H-atom from two phenolic sites to scavenge free radicals. The excellent electron transfer capability of curcumin is because of its unique structure and different functional groups, including a β-diketone and several π electrons that have the capacity to conjugate between two phenyl rings. Therfore, since curcumin is inherently a lipophilic compound, because of its superb intracellular ROS scavenging activity, it can be used as an effective antioxidant for ROS protection within the polar cytoplasm.

  17. Effect of ultraviolet irradiation on free radical scavenging activity of immunosuppressants used in lung transplantation and comparative electron paramagnetic resonance study of kinetics of their interactions with model free radicals.

    Science.gov (United States)

    Stanjek-Cichoracka, A; Żegleń, S; Ramos, P; Pilawa, B; Wojarski, J

    2018-06-01

    The immunosuppressive drugs used in solid organ transplantation or autoimmunological processes were studied by electron paramagnetic resonance (EPR) spectroscopy to estimate their free radical scavenging activity. The interactions of immunosuppressants with free radicals were examined by an X-band (9.3 GHz) EPR spectroscopy and a model of DPPH free radicals. The EPR spectra of DPPH and DPPH interacting with individual drugs were compared. Kinetic studies were performed, and the effect of ultraviolet (UV) irradiation on the free radical scavenging activity of the tested drugs was determined. The free radical scavenging activity of non-irradiated drugs decreased in the order: rapamycin > mycophenolate mofetil > ciclosporin > tacrolimus. UV irradiation increased the free radical scavenging activity of all the tested immunosuppressive drugs, and the effect was highest for tacrolimus. For the non-irradiated samples, the speed of free radical interactions decreased in the order: ciclosporin > tacrolimus > mycophenolate mofetil > rapamycin. UV irradiation only slightly affected the speed of interactions of the immunosuppressive drugs with the model DPPH free radicals. Electron paramagnetic resonance spectroscopy is useful for obtaining information on interactions of immunosuppressive drugs with free radicals. We hypothesized that the long-term immunosuppressive effects of these drugs after transplantation or during autoimmune disorders may be mediated by anti-inflammatory action in addition to the known receptor/cell cycle inhibition. © 2018 John Wiley & Sons Ltd.

  18. Radical-scavenging Activity of Estrogen and Estrogen-like Compounds Using the Induction Period Method

    Directory of Open Access Journals (Sweden)

    Seiichiro Fujisawa

    2007-04-01

    Full Text Available The radical-scavenging activity of estrogens (estrone, 2-hydroxyestradiol,estrogen-like compounds (diethylstilbestrol, DES; bisphenol A, BPA and the mono-phenolic compound 2,6-di-t-butyl-4-methoxyphenol (BMP was investigated using themethod of measuring the induction period for polymerization of methyl methacrylate(MMA initiated by thermal decomposition of 2,2'-azobisisobutyronitrile (AIBN andbenzoyl peroxide (BPO at 70°C using differential scanning calorimetry (DSC. Thestoichiometric factor (n, number of free radicals trapped by one mole of antioxidantmoiety for the AIBN system declined in the order BMP (2.0, 2-hydroxyestradiol (2.0>DES (1.3 > BPA (1.2 > estrone (0.9, whereas that for the BPO system declined in theorder BMP (2.0 >DES (1.9, BPA (1.9 > estrone (1.3 > 2-hydroxyestradiol (0.7. Theinhibition rate constant (kinh x 10-3 M-1s-1 for the AIBN system declined in the orderestrone (2.2 > BPA (2.0 > DES (1.9 > 2-hydroxyestradiol (1.2 > BMP (1.1, whereasthat for the BPO system declined in the order 2-hydroxyestradiol (3.2 > estrone (1.4 >DES (1.2 > BPA (1.0 > BMP (0.9. The radical-scavenging activity for bioactivecompounds such as estrogens should be evaluated using these two methods (the n and kinhto elucidate the mechanism of a particular reaction. The great difference of the n and kinhfor estrogens between the AIBN and BPO system suggested that their oxidation process iscomplex.

  19. Free radical scavenging activity of ethanolic extracts from herbs and spices commercialized in Brazil

    Directory of Open Access Journals (Sweden)

    Lilian Regina Barros Mariutti

    2008-12-01

    Full Text Available Ethanolic extracts from 23 different dried herbs and spices commercialized in Brazil were investigated for their free radical scavenging properties using the stable free radicals 2,2'-diphenyl-β-picrylhydrazyl (DPPH• and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS•+, and Trolox as reference (TEAC for both radicals. The kinetic curves for both radicals showed to follow the first order kinetics model and the decay rate constant (k obs was calculated. For all the samples, the two methods showed a good linear TEAC correlation, indicating that the average reactivity of the compounds present in the ethanolic extracts was similar. Sage and rosemary extracts showed the highest free radical scavenging capacities, while onion showed negligible activity and colorifico, one of the most consumed spices in Brazil, showed low ABTS•+ scavenging activity. Three distinct situations were found for the extracts concerning the DPPH• scavenging capacities: (1 extracts, like rosemary and laurel, that presented the same efficient concentrations (EC50 but differed in the TEAC values and velocities of action (k obs, (2 extracts, such as garlic and basil, that showed similar EC50 and TEAC values, but different k obs values and (3 extracts that reacted at the same velocities but completely differed in the free radical scavenging capacities, like black pepper, savory, nutmeg, rosemary and sage. Similar considerations could be done for the ABTS•+ results. For the first time the ABTS•+ scavenging activity for allspice, basil, cardamom, chives, colorifico, cumin, dill, laurel, marjoram, parsley and tarragon was reported.Extratos etanólicos de 23 ervas e condimentos desidratados comercializados no Brasil foram analisados quanto as suas propriedades antioxidantes utilizando os radicais 2,2'-difenil-β-picrilhidrazil (DPPH• e ácido 2,2'-azino-bis(3-etilbenzotiazolina-6-sulfônico (ABTS•+, Trolox foi usado como referência para ambos radicais

  20. Double C-H activation of ethane by metal-free SO2*+ radical cations.

    Science.gov (United States)

    de Petris, Giulia; Cartoni, Antonella; Troiani, Anna; Barone, Vincenzo; Cimino, Paola; Angelini, Giancarlo; Ursini, Ornella

    2010-06-01

    The room-temperature C-H activation of ethane by metal-free SO(2)(*+) radical cations has been investigated under different pressure regimes by mass spectrometric techniques. The major reaction channel is the conversion of ethane to ethylene accompanied by the formation of H(2)SO(2)(*+), the radical cation of sulfoxylic acid. The mechanism of the double C-H activation, in the absence of the single activation product HSO(2)(+), is elucidated by kinetic studies and quantum chemical calculations. Under near single-collision conditions the reaction occurs with rate constant k=1.0 x 10(-9) (+/-30%) cm(3) s(-1) molecule(-1), efficiency=90%, kinetic isotope effect k(H)/k(D)=1.1, and partial H/D scrambling. The theoretical analysis shows that the interaction of SO(2)(*+) with ethane through an oxygen atom directly leads to the C-H activation intermediate. The interaction through sulfur leads to an encounter complex that rapidly converts to the same intermediate. The double C-H activation occurs by a reaction path that lies below the reactants and involves intermediates separated by very low energy barriers, which include a complex of the ethyl cation suitable to undergo H/D scrambling. Key issues in the observed reactivity are electron-transfer processes, in which a crucial role is played by geometrical constraints. The work shows how mechanistic details disclosed by the reactions of metal-free electrophiles may contribute to the current understanding of the C-H activation of ethane.

  1. Cooked blueberries: anthocyanin and anthocyanidin degradation and their radical-scavenging activity.

    Science.gov (United States)

    Oliveira, Carla; Amaro, L Filipe; Pinho, Olivia; Ferreira, Isabel M P L V O

    2010-08-25

    This study examined anthocyanin and anthocyanidin composition and radical-scavenging activity of three cultivars of blueberries (Vaccinium corymbosum L., cv. Bluecrop, Bluetravel, and Ozarkblue) before and after cooking. A total of 13 anthocyanins were separated and monitored in methanolic extracts of raw fruits by high-performance liquid chromatography/diode array detector (HPLC/DAD). Principal component analysis using the anthocyanin profile as variables revealed differences according to cultivar origin. Of the six common anthocyanidins, four were identified and quantified in the hydrolysates, namely, malvidin, the most abundant, followed by cyanidin, petunidin, and delphynidin. A systematic evaluation of the degradation of anthocyanins and anthocyanidins of blueberries cooked in stuffed fish was performed. The percentage of anthocyanin degradation in cooked blueberries (by progressive heating from 12 to 99 °C for 60 min) ranged between 16 and 30% for Bluecrop, 30-42% for Bluetravel, and 12-41% for Ozarkblue. However, cooked blueberries maintained or increased radical-scavenging activity when evaluated by the 1,1'-diphenyl-2-picrylhydrazyl (DPPH) method. Overall, results show that cooked blueberries can serve as a good source of bioactive phytochemicals.

  2. Study on the role of active radicals on plasma sterilization inside small diameter flexible polymeric tubes

    Science.gov (United States)

    Mstsuura, Hiroto; Fujiyama, Takatomo; Okuno, Yasuki; Furuta, Masakazu; Okuda, Shuichi; Takemura, Yuichiro

    2015-09-01

    Recently, atmospheric pressure discharge plasma has gathered attention in various fields. Among them, plasma sterilization with many types of plasma source has studied for decades and its mechanism is still an open question. If active radicals produced in plasma has main contribution of killing bacterias, direct contact of the so-called plasma flame might not be necessary. To confirm this, sterilization inside small diameter flexible polymeric tubes is studied in present work. DBD type plasma jet is produce by flowing helium gas in a glass tube. A long polymeric tube is connected and plasma jet is introduced into it. Plasma flame length depends on helium gas flow rate, but limited to about 10 cm in our experimental condition. E.colis set at the exit plasma source is easily killed during 10 min irradiation. At the tube end (about 20 cm away from plasma source exit), sterilization is possible with 30 min operation. This result shows that active radical is produced with helium plasma and mist contained in sample, and it can be transferred more than 20 cm during it life time. More plasma diagnostic data will also be shown at the conference. This work was partially supported by the ''ZE Research Program, IAE(ZE27B-4).

  3. Antioxidant activities of traditional plants in Sri Lanka by DPPH free radical-scavenging assay

    Directory of Open Access Journals (Sweden)

    Kotaro Hara

    2018-04-01

    Full Text Available This article describes free radical-scavenging activities of extracts of several plants harvested in Sri Lanka through the 1,1-diphenyl-2-picrylhydrazyl (DPPH assay. These plants have traditionally been used in the indigenous systems of medicine in Sri Lanka, such as Ayurveda, as described below. (English name, “local name in Sri Lanka,” (scientific name.bougainvillea plant, “bouganvilla,” (Bougainvillea grabla, purple fruited pea eggplant,”welthibbatu,” (Solanum trilobatum [1], country borage plant, “kapparawalliya,” (Plectranthus amboinicus [2], malabar nut plant, “adhatoda,” (Justicia adhatoda [3], long pepper plant,”thippili,” (Piper longum [4], holy basil plant, “maduruthala,” (Ocimum tenuiflorum [5], air plant, “akkapana,” (Kalanchoe pinnata [6], plumed cockscomb plant, “kiri-henda,” (Celosia argentea [7], neem plant,”kohomba,” (Azadirachta indica [8], balipoovu plant, “polpala,” (Aerva lanata [9], balloon-vine plant, “wel penera,” (Cardiospermum halicacabum [10], emblic myrobalan plant, “nelli,” (Phyllanthus emblica [11], indian copperleaf plant, “kuppameniya,” (Acalypha indica [12], spreading hogweed plant, “pita sudu sarana,” (Boerhavia diffusa [13], curry leaf plant, “karapincha,” (Murraya koenigii [14], indian pennywort plant, “gotukola,” (Centera asiatica [15], jewish plum plant, “ambarella,”(Spondias dulcis [16]. Keywords: Antioxidative activity, DPPH radical-scavenging assay, Traditional plant, Medical herb

  4. Characterization of fatty acids, bioactive lipids, and radical scavenging activity of Canterbury bells seed oil

    Directory of Open Access Journals (Sweden)

    Hassanien, M. F.R.

    2014-06-01

    Full Text Available The aim of this study was to characterize the chemical composition and radical scavenging activity of Canterbury bells (Campanula medium seed oil. C. medium seeds contained 9.2% extractable oil. The lipid classes, fatty acids, phytosterol and tocopherol composition of C. medium seed oil were determined. The amount of neutral lipids in the oil was the highest, followed by glycolipids and phospholipids. Linoleic and oleic were the main fatty acids. C. medium oil is characterized by high levels of phytosterols and β-sitosterol was the main compound. β-Tocopherol constituted 42.5% of the total tocopherol content followed by γ-tocopherol. The radical scavenging activity (RSA toward 1,1-diphenyl-2-picrylhydrazyl (DPPH radicals and galvinoxyl radicals of C. medium oil were higher than those of extra virgin olive oil. The diverse potential uses of C. medium oil may make this plant industrially important.El objetivo de este estudio fue caracterizar la composición química y la actividad de captación de radicales de aceites de semillas de campanillas de Canterbury (Campanula medium. Las semillas de C. medium contenían 9,2 % de aceite extraíble. Se determinó la composición de las diferentes clases de lípidos, ácidos grasos, fitoesteroles y tocoferoles. La cantidad de lípidos neutros en el aceite fue mayoritario, seguido de glicolípidos y fosfolípidos. Linoleico y oleico fueron los ácidos grasos principales. El aceite de C. medium se caracteriza por altos niveles de fitoesteroles y β-sitosterol fue el compuesto principal. β-tocoferol constituía 42,5 % del contenido total de tocoferol seguido de γ-tocoferol. La actividad de captación de radicales (RSA a 1,1-difenil-2- picrilhidrazil (DPPH y radicales galvinoxil de C. medium fueron superiores a las de aceite de oliva virgen extra. Los diversos usos potenciales de los aceites de C. medium pueden hacer que esta planta pueda ser importante industrialmente.

  5. Evaluation of radical scavenging activity, intestinal cell viability and antifungal activity of Brazilian propolis by-product.

    Science.gov (United States)

    de Francisco, Lizziane; Pinto, Diana; Rosseto, Hélen; Toledo, Lucas; Santos, Rafaela; Tobaldini-Valério, Flávia; Svidzinski, Terezinha; Bruschi, Marcos; Sarmento, Bruno; Oliveira, M Beatriz P P; Rodrigues, Francisca

    2018-03-01

    Propolis is a natural adhesive resinous compound produced by honeybees to protect hives from bacteria and fungi, being extremely expensive for food industry. During propolis production, a resinous by-product is formed. This resinous waste is currently undervalued and underexploited. Accordingly, in this study the proximate physical and chemical quality, as well as the antioxidant activity, radical scavenging activity and cell viability of this by-product were evaluated and compared with propolis in order to boost new applications in food and pharmaceutical industries. The results revealed that the by-product meets the physical and chemical quality standards expected and showed that the propolis waste contains similar amounts of total phenolic content (TPC) and total flavonoid content (TFC) to propolis. Also, a good scavenging activity against reactive oxygen and nitrogen species (ROS and RNS, respectively) determined by the assays of superoxide anion radical (O 2 - ), hydrogen peroxide (H 2 O 2 ), hypochlorous acid (HOCl), nitric oxide (NO) and peroxyl radical (ROO) were determined. Linear positive correlations were established between the TPC of both samples and the antioxidant activity evaluated by three different methods (DPPH, ABTS and FRAP assays). The extracts were also screened for cell viability assays in two different intestinal cell lines (HT29-MTX and Caco-2), showing a viability concentration-dependent. Similarly, the Artemia salina assay, used to assess toxicity, demonstrated the concentration influence on results. Finally, the antifungal activity against ATCC species of Candida was demonstrated. These results suggest that propolis by-product can be used as a new rich source of bioactive compounds for different areas, such as food or pharmaceutical. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Radical scavenging activity of selected medicinal plants from Limpopo province of South Africa.

    Science.gov (United States)

    Chauke, A M; Shai, L J; Mphahlele, P M; Mogale, M A

    2012-01-01

    Plants collected from Limpopo province of South Africa were investigated for their antioxidative potential using the DPPH radical scavenging assay. Acetone extracts of Flueggea virosa had the highest antioxidant activity with an IC₅₀ value of 30 µg/ml, closely matching the ascorbic acid with an IC₅₀ value of 25 µg/ml. The lowest antioxidant readings were observed with extracts of Rhynchosia venulosa (root extract) and Ficus ingens (leaf extract). Acetone extract of Bridelia virosa leaves had the highest phenolic content (156 mg GAE/g extract), while the lowest content was recorded for R. venulosa root extract and leaf extract of F. ingens (8.3 and 17.7 mg GAE/g extract, respectively). There was a linear correlation between antioxidant activity and total phenolic content. Extracts with high phenolic content had low IC₅₀ values, while extracts with low phenolic concentrations had high IC₅₀ values.

  7. Radical activity evaluation in African Palm (Elaeis guineensis Jacq) using phosphorous - 32

    International Nuclear Information System (INIS)

    Rodriguez D, C.G.

    1995-01-01

    Low lands, wet and tropical, its are producing potential of oil palm, since this plant is notoriously bearable to poor soils in nutrients. Oil palm cultivation is relatively new at Colombia, commercial sowings date hardly of 1950s and in spite of this, tenacity and futuristic vision of some entrepreneurs have permitted that this activity, in few existence years, may have had a growing dynamics and strengthening of agricultural sector. The objective of this Thesis, it's to evaluate field conditions of radical activity, making an analysis in utilization efficiency of monoammonium phosphate labeled with 32P that was produced at INEA (today Ingeominas) with an activity of 1mCi/gram. Furthermore, its are intended to define differences of absorption in 1,9 and 17 leaves continuing the palm leaves phyto taxis, with the objective to determine the number of leaf for foliate analysis. The work was carried out in a 6-year-old age cultivation belonging to Uni palma company, located at Cumaral Municipality (Meta Department), situated to 500 meters on sea level, being a representative batch of African palm cultivation at Colombia's Eastern Plains. Soil is classified as Oxi sol, with ph of 4.5 and with high iron and aluminum indices. It was used the Isotopic Tracers methodology, the one which was highly effective, inasmuch as was determined that greater radical activity is found 2.5 meters of plant foot, with a percentage absorption average of 60.8 with respect to other treatments. Due to fact that were not found differences in phosphorus absorption between leaves 1,9 and 17, is recommended for foliate analysis to make use of any number of leaf. Efficiency of use of monoammonium phosphate was decreased (2.0710), something which makes necessary to promote tending studies to improve its behavior, more yet taking into account high cost of fertilizers and environmental pollution risks

  8. Oxidation of winery wastewater by sulphate radicals: catalytic and solar photocatalytic activations.

    Science.gov (United States)

    Rodríguez-Chueca, Jorge; Amor, Carlos; Mota, Joana; Lucas, Marco S; Peres, José A

    2017-10-01

    The treatment of winery effluents through sulphate radical-based advanced oxidation processes (SR-AOPs) driven by solar radiation is reported in this study. Photolytic and catalytic activations of peroxymonosulphate (PMS) and persulphate (KPS and SPS) at different pH values (4.5 and 7) were studied in the degradation of organic matter. Portugal is one of the largest wine producers in Europe. The wine making activities generate huge volume of effluents characterized by a variable volume and organic load, being their seasonal nature one of the most important drawbacks. Recently, SR-AOPs are gradually attracting attention as in situ chemical oxidation technologies, instead of hydroxyl radical AOPs (HR-AOPs). The studied concentrations are suitable to obtain notable values of organic matter degradation, with TOC removal around 50%. In general terms, no notable differences were observed between treatments at pH values 4.5 and 7. Photolytic activation of SPS with solar radiation treatments obtained the highest efficiency (28 and 40% of TOC removal with 1 and 50 mM, respectively, at pH 4.5) in comparison to KPS and PMS. The addition of a transition metal as catalyst, such as Fe(II) or Co(II), increased considerably the TOC removal efficiency higher than 50%, but not in all cases. For instance, the combination KPS or PMS with Co(II) at pH 4.5 did not allow to obtain better results than photolytic activation of these persulphate salts. In summary, the use of SR-AOPs could be a serious alternative as tertiary treatment for winery wastewaters.

  9. New derivatives of 3,4-dihydroisoquinoline-3-carboxylic acid with free-radical scavenging, D-amino acid oxidase, acetylcholinesterase and butyrylcholinesterase inhibitory activity.

    Science.gov (United States)

    Solecka, Jolanta; Guśpiel, Adam; Postek, Magdalena; Ziemska, Joanna; Kawęcki, Robert; Lęczycka, Katarzyna; Osior, Agnieszka; Pietrzak, Bartłomiej; Pypowski, Krzysztof; Wyrzykowska, Agata

    2014-09-30

    A series of 3,4-dihydroisoquinoline-3-carboxylic acid derivatives were synthesised and tested for their free-radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH·), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS·+), superoxide anion radical (O2·-) and nitric oxide radical (·NO) assays. We also studied d-amino acid oxidase (DAAO), acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activity. Almost each of newly synthesised compounds exhibited radical scavenging capabilities. Moreover, several compounds showed moderate inhibitory activities against DAAO, AChE and BuChE. Compounds with significant free-radical scavenging activity may be potential candidates for therapeutics used in oxidative-stress-related diseases.

  10. Reactive radical-driven bacterial inactivation by hydrogen-peroxide-enhanced plasma-activated-water

    Science.gov (United States)

    Wu, Songjie; Zhang, Qian; Ma, Ruonan; Yu, Shuang; Wang, Kaile; Zhang, Jue; Fang, Jing

    2017-08-01

    The combined effects of plasma activated water (PAW) and hydrogen peroxide (H2O2), PAW/HP, in sterilization were investigated in this study. To assess the synergistic effects of PAW/HP, S. aureus was selected as the test microorganism to determine the inactivation efficacy. Also, the DNA/RNA and proteins released by the bacterial suspensions under different conditions were examined to confirm membrane integrity. Additionally, the intracellular pH (pHi) of S. aureus was measured in our study. Electron spin resonance spectroscopy (ESR) was employed to identify the presence of radicals. Finally, the oxidation reduction potential (ORP), conductivity and pH were measured. Our results revealed that the inactivation efficacy of PAW/HP is much greater than that of PAW, while increased H2O2 concentration result in higher inactivation potential. More importantly, as compared with PAW, the much stronger intensity ESR signals and higher ORP in PAW/HP suggests that the inactivation mechanism of the synergistic effects of PAW/HP: more reactive oxygen species (ROS) and reactive nitrogen species (RNS), especially OH and NO radicals, are generated in PAW combined with H2O2 resulting in more deaths of the bacteria.

  11. Free radical scavenging and anti-edematogenic activities of Paullinia elegans Cambess., Sapindaceae, leaves extracts

    Directory of Open Access Journals (Sweden)

    Rodrigo N. Guimarães

    Full Text Available Ethanol extract of the leaves of Paullinia elegans Cambess., Sapindaceae, and its hexane, chloroform, ethyl acetate, and hydroethanol fractions were evaluated for their antiedematogenic and free radical scavenging activities. The ethanol extract and the hexane fraction produced statistically significant inhibition (74.4 and 76.0%, respectively of the ear edema induced by croton oil in mice, observed at doses of 5 mg/ear. The ethyl acetate and hydroethanol fractions showed significant radical scavenging effect in the DPPH assay, with IC50 of 36.7 and 30.1 µg/mL, respectively. Fractionation of the extracts through chromatographic methods afforded epifriedelanol, oleanolic acid 3-O-acetyl, a mixture of stigmasterol 3-β-O-glucopyranoside and sitosterol 3-β-O-glucopyranoside, kaempferol 3,7-O-α-dirhamnopyranoside, kaempeferol-3-O-α-rhamnopyranoside and 2-O-methyl-chiro-inositol. The compounds were identified on the basis of their NMR spectral data and comparison with those of literature.

  12. Involvement of active oxygen in lipid peroxide radical reaction of epidermal homogenate following ultraviolet light exposure

    International Nuclear Information System (INIS)

    Nishi, J.; Ogura, R.; Sugiyama, M.; Hidaka, T.; Kohno, M.

    1991-01-01

    To elucidate the radical mechanism of lipid peroxidation induced by ultraviolet light (UV) irradiation, an electron spin resonance (ESR) study was made on epidermal homogenate prepared from albino rat skin. The exposure of the homogenate to UV light resulted in an increase in lipid peroxide content, which was proportional to the time of UV exposure. Using ESR spin trapping (dimethyl-1-pyrroline-N-oxide, DMPO), the DMPO spin adduct spectrum of lipid radicals (L.) was measured following UV exposure (DMPO-L.:aN = 15.5 G, aH = 22.7 G), as was the spectrum of DMPO-hydroxyl radical (DMPO-OH, aN = aH = 15.5 G). In the presence of superoxide dismutase, the DMPO spin adduct spectrum of lipid radicals was found to be reduced remarkably. Therefore, it was shown that the generation of the lipid radicals partially involves superoxide anion radicals, in addition to hydroxyl radicals. In the ESR free-radical experiment, an ESR signal appeared at g = 2.0064 when the ESR tube filled with homogenate was exposed to UV light at -150 degrees C. The temperature-dependent change in the ESR free radical signal of homogenate exposed to UV light was observed at temperatures varying from -150 degrees C to room temperature. By using degassed samples, it was confirmed that oxygen is involved in the formation of the lipid peroxide radicals (LOO.) from the lipid radicals (L.)

  13. Change in chemical constituents and free radical-scavenging activity during Pear (Pyrus pyrifolia) cultivar fruit development.

    Science.gov (United States)

    Cho, Jeong-Yong; Lee, Sang-Hyun; Kim, Eun Hee; Yun, Hae Rim; Jeong, Hang Yeon; Lee, Yu Geon; Kim, Wol-Soo; Moon, Jae-Hak

    2015-01-01

    Changes in chemical constituent contents and DPPH radical-scavenging activity in fruits of pear (Pyrus pyrifolia) cultivars during the development were investigated. The fruits of seven cultivars (cv. Niitaka, Chuhwangbae, Wonhwang, Hwangkeumbae, Hwasan, Manpungbae, and Imamuraaki) were collected at 15-day intervals after day 20 of florescence. Vitamins (ascorbic acid and α-tocopherol), arbutin, chlorogenic acid, malaxinic acid, total caffeic acid, total flavonoids, and total phenolics were the highest in immature pear fruit on day 20 after florescence among samples at different growth stages. All of these compounds decreased gradually in the fruit during the development. Immature pear fruit on day 35 or 50 after florescence exhibited higher free radical-scavenging activity than that at other times, although activities were slightly different among cultivars. The chemical constituent contents and free radical-scavenging activity were largely different among immature fruits of the pear cultivars, but small differences were observed when they matured.

  14. Melanocortin Tetrapeptide Ac-His-DPhe-Arg-Trp-NH2 Modified at the Para Position of the Benzyl Side Chain (DPhe): Importance for Mouse Melanocortin-3 Receptor Agonist versus Antagonist Activity

    OpenAIRE

    Proneth, Bettina; Pogozheva, Irina D.; Portillo, Federico P.; Mosberg, Henry I.; Haskell-Luevano, Carrie

    2008-01-01

    The melanocortin-3 and -4 receptors (MC3R, MC4R) have been implicated in energy homeostasis and obesity. Whereas the physiological role of the MC4R is extensively studied, little is known about the MC3R. One caveat is the limited availability of ligands that are selective for the MC3R. Previous studies identified Ac-His-DPhe(p-I)-Arg-Trp-NH2, which possessed partial agonist/antagonist pharmacology at the mMC3R while retaining full nanomolar agonist pharmacology at the mMC4R. These data allowe...

  15. TRP channel functions in the gastrointestinal tract.

    Science.gov (United States)

    Yu, Xiaoyun; Yu, Mingran; Liu, Yingzhe; Yu, Shaoyong

    2016-05-01

    Transient receptor potential (TRP) channels are predominantly distributed in both somatic and visceral sensory nervous systems and play a crucial role in sensory transduction. As the largest visceral organ system, the gastrointestinal (GI) tract frequently accommodates external inputs, which stimulate sensory nerves to initiate and coordinate sensory and motor functions in order to digest and absorb nutrients. Meanwhile, the sensory nerves in the GI tract are also able to detect potential tissue damage by responding to noxious irritants. This nocifensive function is mediated through specific ion channels and receptors expressed in a subpopulation of spinal and vagal afferent nerve called nociceptor. In the last 18 years, our understanding of TRP channel expression and function in GI sensory nervous system has been continuously improved. In this review, we focus on the expressions and functions of TRPV1, TRPA1, and TRPM8 in primary extrinsic afferent nerves innervated in the esophagus, stomach, intestine, and colon and briefly discuss their potential roles in relevant GI disorders.

  16. Inhibition of platelet aggregation and in vitro free radical scavenging activity of dried fruiting bodies of Pleurotus eous.

    Science.gov (United States)

    Suseem, S R; Saral, Mary

    2015-07-01

    To evaluate the ethyl acetate, methanol and aqueous extracts of dried fruiting bodies of Pleurotus eous for its anti-platelet activity on human volunteer's blood. And also to analyze the free radical scavenging property of the extracts of P.eous by using various in vitro models. Anti-platelet activity of dried fruiting bodies of P.eous was evaluated by in vitro model using blood platelets. Inhibition of platelet aggregation was monitored after pre-incubation of platelets with the crude extracts of mushroom P.eous. Antioxidant activities of extracts of P.eous were evaluated by different in vitro experiments, namely, 1, 1-diphenyl-2-picryl hydrazyl (DPPH), superoxide, hydroxyl radical and lipid peroxide radical models. Crude extracts of mushroom P.eous inhibited platelet aggregation dose-dependently which was induced by adenosine diphosphate (ADP). At a maximum concentration of 10 mg/mL, methanol extract effected 64.02% inhibition of lipid per-oxidation and 50.12% scavenging effect on superoxide anion radical. Aqueous extract of P.eous have shown 69.43% chelating ability on ferrous ions, 24.27% scavenging effect on hydroxyl radical and 49.57% scavenging effect on DPPH radical at 10 mg/mL. Increasing concentrations of the extract were found to cause progressively decreasing of the intensity of absorbance. Anti-platelet effects could be related in part to the polyphenolic compounds present in the extracts. Antioxidant activity results indicated the free radical scavenging property of the extracts of P.eous which might be due to the high content of phenolic compounds and flavonoids.

  17. In vitro antioxidant and free radical scavenging activity of different parts of Tabebuia pallida growing in Bangladesh.

    Science.gov (United States)

    Rahman, Md Mahbubur; Islam, Md Badrul; Biswas, Mohitosh; Khurshid Alam, A H M

    2015-10-30

    In humans, many diseases are associated with the accumulation of free radicals. Antioxidants can scavenge free radicals and minimize their impact. Therefore, the search for naturally occurring antioxidants of plant origin is imperative. Here, we aimed to investigate the antioxidant and free radical scavenging properties of methanolic extracts from Tabebuia pallida (T. pallida) stem bark (TPSB), root bark (TPRB), leaves (TPL), and flowers (TPF). The antioxidant and free radical scavenging activity were determined by several standard methods using spectrophotomer. Total phenolic and flavonoid contents were estimated using Folin-Ciocalteu reagent and aluminum chloride colorimetric assay methods, respectively. Among the extracts, TPL showed the highest total antioxidant capacity followed by TPRB, TPF, and TPSB. Based on DPPH and hydroxyl radical scavenging activity, TPL showed strong scavenging activity (91.05 ± 1.10 and 62.00 ± 0.57) with IC50 of 9.20 ± 0.28 and 46.00 ± 2.84 μg/mL, respectively when compared with standard BHT (IC50 of 7.00 ± 0.25 μg/mL) and CA (75.00 ± 0.14 μg/mL). These results suggest that TPL had the highest radical scavenging activity among the extractives that closely resembled the standard's. In lipid peroxidation inhibition assay, TPL exhibited the most potent inhibitory activity (83.18 ± 2.12 %) with IC50 of 12.00 ± 2.12 μg/mL, which closely resembled standard CA (IC50 of 10.50 ± 0.28 μg/mL). Also, the reducing capacity on ferrous ion was in the following order: TPL > TPRB > TF > TPSB. The phenolic and flavonoid contents of TPL were higher than other extractives. A positive correlation (p value free radical (DPPH(·) and (·)OH) scavenging efficiencies and lipid peroxidation inhibition activity. Methanolic extract of T. pallida leaf is a potential source of natural antioxidants and serves as an effective free radical scavenger and/or inhibitor. Hence, T. pallida might be a good plant-based pharmaceutical product for several

  18. Antiglycation, radical scavenging, and semicarbazide-sensitive amine oxidase inhibitory activities of acetohydroxamic acid in vitro

    Directory of Open Access Journals (Sweden)

    Liu YH

    2017-07-01

    Full Text Available Yuh-Hwa Liu,1,2,* Yeh-Lin Lu,3,* Der-Zen Liu,4 Wen-Chi Hou5 1Division of Gastroenterology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan; 2Department of General Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; 3Department of Pharmacy, Taipei Medical University, Taipei, Taiwan; 4Graduate Institute of Biomedical Materials and Tissue Engineering, Taipei Medical University, Taipei, Taiwan; 5Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan *These authors contributed equally to this work Abstract: Advanced glycation endproducts (AGEs can promote intracellular reactive oxygen species production, and the levels of AGEs are highly correlated with cardiovascular disease and diabetes complications. Acetohydroxamic acid (acetH is a bacterial urease inhibitor drug used to treat kidney stones and infections in the urinary tract, and hydroxyurea (HU is a drug used for antineoplasm and sickle cell diseases. Both acetH and HU are hydroxamic acid derivatives. It was found that acetH and HU at 2.5 or 5 mM showed anti-AGE formation by lowering the AGEs’ fluorescent intensities and Nε-(carboxymethyllysine formation in bovine serum albumin/galactose models, and both showed better and significant differences (P<0.05 compared to the positive control of aminoguanidine. Regarding radical scavenging activities, the half-inhibition concentrations (IC50 of acetH against α,α-diphenyl-β-picrylhydrazyl radical and hydroxyl radical were 34.86 and 104.42 µM, respectively. The IC50 of acetH against semicarbazide-sensitive amine oxidase was 10.56 µM, and acetH showed noncompetitive inhibition respective to the substrates (benzylamine. The antiglycation, antioxidant, and semicarbazide-sensitive amine oxidase inhibitory activities of acetH prove that it has the potential for treating cardiovascular disease and diabetes complications and it needs further investigation in animal models. Keywords: acetH, AGEs, Nε

  19. Wine Chemical Composition and Radical Scavenging Activity of Some Cabernet Franc Clones.

    Science.gov (United States)

    Popovic-Djordjevic, Jelena; Pejin, Boris; Dramicanin, Aleksandra; Jovic, Sonja; Vujovic, Dragan; Zunic, Dragoljub; Ristic, Renata

    2017-01-01

    Three clones of Cabernet Franc (Nos. 02, 010 and 012) were selected in the last phase of clonal selection in Serbia. Wines made from each clone were assessed for quality parameters and taste during five consecutive vintages (2008-2012) and compared to the standard. The wine quality was determined based on the following parameters: alcohol, total extract, anthocyanins, tannins, pH, titratable acidity, volatile acidity, aldehydes, esters and reducing sugars, relative density, ash, colour, tonality, and tasting score. In the last year of the study, grapes and wines of Cabernet Franc clones and a standard were subjected to a chemical analysis of their phenolic composition, resveratrol and radical scavenging activity. In the last year of the study, grapes and wines of Cabernet Franc clones and a standard were subjected to a chemical analysis of their phenolic composition, resveratrol and radical scavenging activity. Chemical analyses of grapes and wines along with sensory and radical scavenging activity evaluations were done according to the standard procedures. The wines of the clone No. 010 showed some superior properties compared to the other two clones and the standard; in five-year period the average concentration of anthocyanins (179±3.8 mg/L) and polyphenolics (1.85±0.02 g/L) was significantly higher than in wines of clones and the standard, (168-173 mg/L and 1.63-1.74 g/L for anthocyanins and phenolics, respectively). Furthermore, the same clone had a higher alcohol content (13.97±0.03%) in each year of the study, which indicated that it ripened faster than other clones (13.06-13.08 %) and compared to the standard (13.04±0.07%). This finding suggested that the clone No. 010 could possibly have a significant economic impact and further increase popularity of Cabernet Franc in a cooler climate viticultural region. It was also found to have the highest contents of aldehydes (488±1.54 mg/L) and esters (322±0.71 mg/L) compared to aldehydes (452-467 mg/L) and

  20. Relational iterations and emotional activations: towards a radicalization of processuality of collective identities

    Directory of Open Access Journals (Sweden)

    María Martínez

    2018-03-01

    Full Text Available Collective identity has been conceptualized by social movement theories mainly as a definition. In this text, based in feminist theories, I argue that the conceptualization of collective identity as a definition forgets other fundamental dimensions —mainly relations and emotions— and, moreover, limits its processual character. This argument is based on the study of contemporary feminist mobilizations in Spain through a qualitative fieldwork (quasi-biographical interviews, focus groups, participant observations and the analysis of written and graphic materials. The analysis allows the widening of dimensions of collective identities —from definitions to relations and emotions— as well as the radicalization of their processuality by placing the notions of iteration and activation at the heart of the analysis. I offer a theoretical-analytical proposal that understands that collective identities are but partial materializations, always unfinished processes.

  1. Novel Water Soluble Chitosan Derivatives with 1,2,3-Triazolium and Their Free Radical-Scavenging Activity

    Directory of Open Access Journals (Sweden)

    Qing Li

    2018-03-01

    Full Text Available Chitosan is an abundant and renewable polysaccharide, which exhibits attractive bioactivities and natural properties. Improvement such as chemical modification of chitosan is often performed for its potential of providing high bioactivity and good water solubility. A new class of chitosan derivatives possessing 1,2,3-triazolium charged units by associating “click reaction” with efficient 1,2,3-triazole quaternization were designed and synthesized. Their free radical-scavenging activity against three free radicals was tested. The inhibitory property and water solubility of the synthesized chitosan derivatives exhibited a remarkable improvement over chitosan. It is hypothesized that triazole or triazolium groups enable the synthesized chitosan to possess obviously better radical-scavenging activity. Moreover, the scavenging activity against superoxide radical of chitosan derivatives with triazolium (IC50 < 0.01 mg mL−1 was more efficient than that of derivatives with triazole and Vitamin C. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH and hydroxyl radical-scavenging assay, the same pattern were observed, which should be related to the triazolium grafted at the periphery of molecular chains.

  2. A new method for measuring scavenging activity of antioxidants to the hydroxyl radical formed by gamma-irradiation

    International Nuclear Information System (INIS)

    Yoshioka, Hiroe; Ohashi, Yasunori

    2000-01-01

    A new method using ESR spin trapping was proposed for measuring scavenging activity of antioxidants to the hydroxyl (OH) radical. (-)-epigallocatechin gallate (EGCg) and 5,5-dimethyl-l-pyrroline N-oxide (DMPO) were used as an antioxidant and a spin trapping agent, respectively. Conventional method using a Fenton reaction had some defects on the estimation of the activity, because antioxidant disturbed the generating system of OH radical besides it scavenged the spin adduct (DMPO-OH). This method used intense γ-irradiation as OH radical generating system, and the intensity decrease of DMPO-OH after the end of the irradiation was followed to obtain the rate constant of the scavenging of DMPO-OH with EGCg and to estimate the quantity of DMPO-OH formed during γ-irradiation. By using these values, the reaction rate constant between OH radical and EGCg was calculated as a ratio to that of DMPO. It was shown that this method is useful to compare precisely the OH radical scavenging activity of various antioxidants. (author)

  3. Catalytic surface radical in dye-decolorizing peroxidase: a computational, spectroscopic and site-directed mutagenesis study

    Science.gov (United States)

    Linde, Dolores; Pogni, Rebecca; Cañellas, Marina; Lucas, Fátima; Guallar, Victor; Baratto, Maria Camilla; Sinicropi, Adalgisa; Sáez-Jiménez, Verónica; Coscolín, Cristina; Romero, Antonio; Medrano, Francisco Javier; Ruiz-Dueñas, Francisco J.; Martínez, Angel T.

    2014-01-01

    Dye-decolorizing peroxidase (DyP) of Auricularia auricula-judae has been expressed in Escherichia coli as a representative of a new DyP family, and subjected to mutagenic, spectroscopic, crystallographic and computational studies. The crystal structure of DyP shows a buried haem cofactor, and surface tryptophan and tyrosine residues potentially involved in long-range electron transfer from bulky dyes. Simulations using PELE (Protein Energy Landscape Exploration) software provided several binding-energy optima for the anthraquinone-type RB19 (Reactive Blue 19) near the above aromatic residues and the haem access-channel. Subsequent QM/MM (quantum mechanics/molecular mechanics) calculations showed a higher tendency of Trp-377 than other exposed haem-neighbouring residues to harbour a catalytic protein radical, and identified the electron-transfer pathway. The existence of such a radical in H2O2-activated DyP was shown by low-temperature EPR, being identified as a mixed tryptophanyl/tyrosyl radical in multifrequency experiments. The signal was dominated by the Trp-377 neutral radical contribution, which disappeared in the W377S variant, and included a tyrosyl contribution assigned to Tyr-337 after analysing the W377S spectra. Kinetics of substrate oxidation by DyP suggests the existence of high- and low-turnover sites. The high-turnover site for oxidation of RB19 (kcat> 200 s−1) and other DyP substrates was assigned to Trp-377 since it was absent from the W377S variant. The low-turnover site/s (RB19 kcat ~20 s−1) could correspond to the haem access-channel, since activity was decreased when the haem channel was occluded by the G169L mutation. If a tyrosine residue is also involved, it will be different from Tyr-337 since all activities are largely unaffected in the Y337S variant. PMID:25495127

  4. Innate catalytic and free radical scavenging activities of silver nanoparticles synthesized using Dillenia indica bark extract.

    Science.gov (United States)

    Mohanty, Alfa S; Jena, Bhabani S

    2017-06-15

    A green approach was envisaged for the rapid synthesis of stable silver nanoparticles in an aqueous medium using phenolic rich ethanolic bark extract from D. indica with marked free radical scavenging and reducing ability. Biosynthesis of silver nanoparticles (AgNPs) was confirmed and characterized by using UV-visible spectroscopy, particle size analyzer, X-ray diffractometry (XRD), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FT-IR). Bio-reduction of Ag+ was confirmed with the appearance of golden yellow coloration within 5-10min at 45°C with maximum absorbance at 421nm. XRD analysis of AgNPs indicated the crystalline nature of metallic Ag. As analyzed by TEM, AgNPs were found to be spherical in shape, well dispersed and size varied from 15 to 35nm and dynamic light scattering (DLS) studies showed the average particle size of 29nm with polydispersity index (PDI) of 0.280. Synthesized AgNPs were showing surface functionalization as revealed through FTIR studies. These AgNPs were observed to be highly stable at room temperature (28±2°C) for more than 3months, thereby indicating the ethanolic extract of D. indica was a reducing as well as a capping agent for stabilization of AgNPs. Moreover, these green synthesized AgNPs showed enhanced free radical scavenging and excellent catalytic activities when used in the reduction of 4-nitrophenol and methylene blue dye, at room temperature. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Prevention of alloimmunization by ultraviolet-B irradiation. Inactivation of leukocytes and the generation of active oxygen and radicals

    International Nuclear Information System (INIS)

    Takahashi, Tsuneo; Mogi, Yuko; Sekiguchi, Sadayoshi; Akasaka, Junichi; Kamo, Naoki; Kuwabara, Mikinori.

    1994-01-01

    UV-B irradiation of platelet concentrates (PC) has been tried in several institutes to inactivate leukocytes in PC and prevent alloimmunization on platelet transfusion. However, the mechanism of inactivation of leukocytes contaminating PC has not been fully understood. It is known that UV-B light is absorbed by photosensitizers in cells and produces active oxygen and radicals, such as singlet oxygen, superioxide anions and hydroxyl radicals. These active oxygen or radicals should injure cellular components and this could cause the suppression of cellular functions. In this study, we investigated the relationships among UV-B irradiation, free radical generation and leukocyte inactivation. We found the evidence that active oxygen and radicals were produced in peripheral blood mononuclear cells by UV-B irradiation. UV-B irradiation suppressed the stimulatory function of leukocytes in a mixed lymphocyte reaction (MLR), and the suppression depended on the dosage of UV-B. Even a low dosage of UV-B, 10 J/m 2 , could inhibit the MLR if the irradiated cells were incubated at 37degC for 24 hours before co-culture with responder cells. Treatments of cells with the exogenous singlet oxygen or superoxide anions also caused suppression of the stimulatory function in the MLR, inhibition of capping formation of HLA-DR antigens, and an increase of intracellular free Ca 2+ levels as did the UV-B treatment. These results indicate that the active oxygen or radicals generated in UV-B-irradiated leukocytes could be one of the causes of leukocyte inactivation. (author0

  6. Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Reed, James R., E-mail: rreed@lsuhsc.edu [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); Cawley, George F.; Ardoin, Taylor G. [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); Dellinger, Barry; Lomnicki, Slawomir M.; Hasan, Farhana; Kiruri, Lucy W. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Backes, Wayne L. [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States)

    2014-06-01

    Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230 °C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. - Highlights: • Combustion of organic pollutants generates long-lived particulate radicals (EPFRs). • EPFRs inhibit metabolism by all cytochromes P450 tested in rat liver microsomes. • EPFR-mediated inhibition is related to

  7. Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes

    International Nuclear Information System (INIS)

    Reed, James R.; Cawley, George F.; Ardoin, Taylor G.; Dellinger, Barry; Lomnicki, Slawomir M.; Hasan, Farhana; Kiruri, Lucy W.; Backes, Wayne L.

    2014-01-01

    Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230 °C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. - Highlights: • Combustion of organic pollutants generates long-lived particulate radicals (EPFRs). • EPFRs inhibit metabolism by all cytochromes P450 tested in rat liver microsomes. • EPFR-mediated inhibition is related to

  8. Evaluation Of The Radical Activity In African Palm (Elaeis Guineensis JACQ) Using Match-32

    International Nuclear Information System (INIS)

    Delgado R, Conrado G.

    1995-01-01

    The low, humid and tropical lands, are potential producers of palm of oil, since this plant is notoriously tolerant to the poor floors in nutritious. The palm of oil cultivation is relatively new, commercial seeding hardly dates of 1950 and in spite of this, the futurist vision of some managers they have allowed that this activity, in few years of existence, have had a growing dynamics of the agricultural sector. The objective of this study, was to evaluate under field conditions the radical activity, making an analysis in the efficiency of use of the mono-ammonic phosphate with 32P that it took place in the INEA with a lmCi/gram activity. it is Also to determine the differences of absorption in the leaves 1,9 and 17 following the phylotaxia of the palm leaves, in order to determine the leaf number for the analysis to foliate. The work was carried out in a 6 year-old cultivation belonging to the company Unipalma, located in the municipality of Cumaral, department of the goal, located to 500 msnm, being a representative lot where African palm is cultivated in the oriental plains. I am accustomed to classified as an Oxi sol, with pH of 4.5 and with high iron contents and aluminum. In this work the methodology isotopic was used of tracer. The study checked that the methodology was highly effective, since it was determined that the biggest radical activity is 2.5 m of the foot of the plant, with a percentage average of absorption of 60.8 with regard to the other treatments. Because they were not differences in match absorption among the leaves 1, 9 and 17, it is recommended for the analysis to foliate to make use of the any leaf number. As for the efficiency of use of the mono-ammonic phosphate it was low (2.0710), it becomes necessary to promote studies tendentious to improve their behavior, stiller keeping in mind the high cost of the fertilizers and the risks of ecological contamination

  9. Adaptive Neuro-Fuzzy Inference System Applied QSAR with Quantum Chemical Descriptors for Predicting Radical Scavenging Activities of Carotenoids.

    Science.gov (United States)

    Jhin, Changho; Hwang, Keum Taek

    2015-01-01

    One of the physiological characteristics of carotenoids is their radical scavenging activity. In this study, the relationship between radical scavenging activities and quantum chemical descriptors of carotenoids was determined. Adaptive neuro-fuzzy inference system (ANFIS) applied quantitative structure-activity relationship models (QSAR) were also developed for predicting and comparing radical scavenging activities of carotenoids. Semi-empirical PM6 and PM7 quantum chemical calculations were done by MOPAC. Ionisation energies of neutral and monovalent cationic carotenoids and the product of chemical potentials of neutral and monovalent cationic carotenoids were significantly correlated with the radical scavenging activities, and consequently these descriptors were used as independent variables for the QSAR study. The ANFIS applied QSAR models were developed with two triangular-shaped input membership functions made for each of the independent variables and optimised by a backpropagation method. High prediction efficiencies were achieved by the ANFIS applied QSAR. The R-square values of the developed QSAR models with the variables calculated by PM6 and PM7 methods were 0.921 and 0.902, respectively. The results of this study demonstrated reliabilities of the selected quantum chemical descriptors and the significance of QSAR models.

  10. Adaptive Neuro-Fuzzy Inference System Applied QSAR with Quantum Chemical Descriptors for Predicting Radical Scavenging Activities of Carotenoids.

    Directory of Open Access Journals (Sweden)

    Changho Jhin

    Full Text Available One of the physiological characteristics of carotenoids is their radical scavenging activity. In this study, the relationship between radical scavenging activities and quantum chemical descriptors of carotenoids was determined. Adaptive neuro-fuzzy inference system (ANFIS applied quantitative structure-activity relationship models (QSAR were also developed for predicting and comparing radical scavenging activities of carotenoids. Semi-empirical PM6 and PM7 quantum chemical calculations were done by MOPAC. Ionisation energies of neutral and monovalent cationic carotenoids and the product of chemical potentials of neutral and monovalent cationic carotenoids were significantly correlated with the radical scavenging activities, and consequently these descriptors were used as independent variables for the QSAR study. The ANFIS applied QSAR models were developed with two triangular-shaped input membership functions made for each of the independent variables and optimised by a backpropagation method. High prediction efficiencies were achieved by the ANFIS applied QSAR. The R-square values of the developed QSAR models with the variables calculated by PM6 and PM7 methods were 0.921 and 0.902, respectively. The results of this study demonstrated reliabilities of the selected quantum chemical descriptors and the significance of QSAR models.

  11. Prostaglandin H synthase-mediated bioactivation of the amino acid pyrolysate product Trp P-2

    Energy Technology Data Exchange (ETDEWEB)

    Petry, T.W.; Krauss, R.S.; Eling, T.E.

    1986-08-01

    We report evidence that the mutagen and carcinogen 3-amino-1-methyl-5H pyrido(4,3b)indole (Trp P-2) is a substrate for co-oxidation by prostaglandin H synthase (PHS) in ram seminal vesicle (RSV) microsomes. Trp P-2 serves as a reducing cofactor for the hydroperoxidase activity of PHS as shown by the concentration-dependent inhibition of the hydroperoxidase catalyzed incorporation of molecular oxygen into phenylbutazone. Spectral data suggest that this metabolism results in disruption of the double bond conjugation within the nucleus of the molecule. A single metabolite peak which was dependent upon arachidonic acid and substrate concentration was separated from the parent compound by h.p.l.c. following incubation with RSV microsomes. Co-oxidation of Trp P-2 produced reactive intermediates which bound covalently to microsomal protein (9 nmol/mg) and to calf thymus DNA (475 pmol/mg). Binding was inhibited by indomethacin, and supported by substitution of hydrogen peroxide for arachidonic acid. These data suggest a possible role for PHS in the in situ activation of Trp P-2 to its ultimate carcinogenic form in tissues which contain PHS.

  12. Free Radical Scavenging and Alpha/Beta-glucosidases Inhibitory Activities of Rambutan (Nephelium lappaceum L. Peel Extract

    Directory of Open Access Journals (Sweden)

    Wahyu Widowati

    2015-12-01

    Full Text Available BACKGROUND: Diabetes mellitus (DM is associated with oxidative reaction and hyperglycemic condition. Human body has an antioxidant defense system toward free radical, but overproduction of free radical causing imbalance condition between the free radical and the antioxidant defense in the body that lead to several diseases, including DM. Glucosidase is an enzyme that hydrolize carbohydrates causing increase of blood glucose level, so by inhibiting this enzyme blood glucose level in plasma could be effectively decreased. Rambutan (Nephelium lappaceum L. peel has been reported to have many potential roles, such as antioxidant and anti-glycemia. Therefore our current study was conducted to evaluate possible effectivity of Rambutan peel to scavenge free radical and to inhibit α- and β-glucosidases. METHODS: Rambutan peel extraction (RPE was performed based on maceration method. Geraniin was used as control. For antioxidant study, 2,2-diphenyl-1- picrylhydrazyl (DPPH free radical scavenging test was performed. For glucosidase inhibitory activity study,  α- and β-glucosidases inhibitory activity tests were performed. Results were analyzed for median of Inhibitory Concentration (IC50. RESULTS: The scavenging activity of RPE was comparable with Geraniin. Meanwhile, the α-glucosidase inhibitory activity of RPE was higher than the one of Geraniin. The α-glucosidase-inhibitory-activity IC50 of RPE and Geraniin were 0.106±0.080 μg/ml and 16.12±0.29 μg/ml, respectively. The β-glucosidase inhibitory activity of RPE was also higher than the one of Geraniin. The β-glucosidase-inhibitory-activity IC50 of RPE and Geraniin were 7.02±0.99 μg/ml and 19.81±0.66 μg/ml, respectively. CONCLUSIONS: Since RPE showed comparable free radical scavenging activity with Geraniin and higher α- and β-glucosidases inhibitory activities than Geraniin, RPE could be suggested as a promising antioxidant and antiglycemic agent.  KEYWORDS

  13. Improved Synthesis of 4-Cyanotryptophan and Other Tryptophan Analogues in Aqueous Solvent Using Variants of TrpB from Thermotoga maritima.

    Science.gov (United States)

    Boville, Christina E; Romney, David K; Almhjell, Patrick J; Sieben, Michaela; Arnold, Frances H

    2018-04-27

    The use of enzymes has become increasingly widespread in synthesis as chemists strive to reduce their reliance on organic solvents in favor of more environmentally benign aqueous media. With this in mind, we previously endeavored to engineer the tryptophan synthase β-subunit (TrpB) for production of noncanonical amino acids that had previously been synthesized through multistep routes involving water-sensitive reagents. This enzymatic platform proved effective for the synthesis of analogues of the amino acid tryptophan (Trp), which are frequently used in pharmaceutical synthesis as well as chemical biology. However, certain valuable compounds, such as the blue fluorescent amino acid 4-cyanotryptophan (4-CN-Trp), could only be made in low yield, even at elevated temperature (75 °C). Here, we describe the engineering of TrpB from Thermotoga maritima that improved synthesis of 4-CN-Trp from 24% to 78% yield. Remarkably, although the final enzyme maintains high thermostability ( T 50 = 93 °C), its temperature profile is shifted such that high reactivity is observed at ∼37 °C (76% yield), creating the possibility for in vivo 4-CN-Trp production. The improvements are not specific to 4-CN-Trp; a boost in activity at lower temperature is also demonstrated for other Trp analogues.

  14. Optimization of hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus in submerged fermentation using response surface methodology

    NARCIS (Netherlands)

    Chen, H.; Xu, X.; Zhu, Y.

    2010-01-01

    The objectives of this study were to investigate the effect of fermentation medium on the hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus by response surface methodology (RSM). A two-level fractional factorial design was used to evaluate the effect of different

  15. Screening of free radical scavenging capacity and antioxidant activities of Rosmarinus officinalis extracts with focus on location and harvesting times

    NARCIS (Netherlands)

    Yesil Celiktas, O.; Girgin, G.; Orhan, H.; Wichers, H.J.; Bedir, E.; Vardar Sukan, F.

    2007-01-01

    Methanolic extracts from the leaves of Rosmarinus officinalis (rosemary) harvested from different locations of Turkey at four different times of the year were analyzed by HPLC, and their radical scavenging capacities and antioxidant activities were studied by various assays. The amounts of carnosol,

  16. Effect of tocopherol treatment on deterioration of edible oil quality (acid value, carbonyl value, free fatty acid and radical activity).

    Science.gov (United States)

    Ogata, Fumihiko; Tanaka, Yuko; Kawasaki, Naohito

    2014-01-01

    In this study, waste edible oil was prepared by both heat and aeration treatment, and the increasing inhibitive effect of tocopherol treatment on the acid value (AV) and carbonyl value (CV) of the oil was investigated. The AV and CV of waste edible oil treated with tocopherol were 0.1-1.0% lower than those of the nontreated oil, indicating that tocopherol exerted a radical-scavenging activity. The concentration of tocopherol decreased with time, while that of the remaining 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals increased. These results suggest that the addition of tocopherol proved to be useful for preventing the deterioration of waste edible oil.

  17. Physicochemical characterisation and radical-scavenging activity of Cucurbitaceae seed oils.

    Science.gov (United States)

    Jorge, Neuza; da Silva, Ana Carolina; Malacrida, Cassia Roberta

    2015-01-01

    Oils extracted from Cucurbitaceae seeds were characterised for their fatty acid and tocopherol compositions. In addition, some physicochemical characteristics, total phenolic contents and the radical-scavenging activities were determined. Oil content amounted to 23.9% and 27.1% in melon and watermelon seeds, respectively. Physicochemical characteristics were similar to those of other edible oils and the oils showed significant antioxidant activities. Fatty acid composition showed total unsaturated fatty acid content of 85.2-83.5%, with linoleic acid being the dominant fatty acid (62.4-72.5%), followed by oleic acid (10.8-22.7%) and palmitic acid (9.2-9.8%). The oils, especially watermelon seed oil, showed high total tocopherol and phenolic contents. The γ-tocopherol was the predominant tocopherol in both oils representing 90.9 and 95.6% of the total tocopherols in melon and watermelon seed oils, respectively. The potential utilisation of melon and watermelon seed oils as a raw material for food, chemical and pharmaceutical industries appears to be favourable.

  18. Evaluation of the free radical scavenging activity and radioprotective efficacy of Grewia asiatica fruit

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Krishna V; Sisodia, Rashmi [Radiation Biology Laboratory, Department of Zoology, University of Rajasthan, Jaipur, Rajasthan-302055 (India)], E-mail: rashsisodia@yahoo.co.in

    2009-09-01

    The radioprotective effect of Grewia asiatica fruit (GAE) which contains anthocyanin-type cyanidin 3-glucoside, vitamins C and A, minerals, carotenes and dietary fibre was studied. For the study Swiss albino mice were divided into five groups: (1) control (vehicle treated); (2) GAE treated (700 mg kg{sup -1} day{sup -1} for 15 days); (3) irradiated (5 Gy); (4) GAE+irradiated and (5) irradiated+GAE treated. The irradiation of animals resulted in a significant elevation of lipid peroxidation in terms of thiobarbituric acid reactive substances (TBARS) content and depletion in glutathione (GSH) and protein levels at all intervals studied, namely 1-30 days, in comparison to the control group. Treatment of mice with GAE before and after irradiation caused a significant depletion in TBARS content followed by a significant elevation in GSH and protein concentration in the intestine and testis of mice at all post-irradiation autopsy intervals in comparison to irradiated mice. Significant protection of DNA and RNA in testis was also noticed. GAE was found to have strong radical scavenging activity in 2,2-diphenyl-1-picrylhydrazyl (DPPH{sup *}) and O{sub 2}{sup -} assays and also showed in vitro radioprotective activity in protein carbonyl assay in a dose-dependent manner. The above results prove the radioprotective efficacy of GAE.

  19. Remote C−H Activation of Quinolines through Copper-Catalyzed Radical Cross-Coupling

    KAUST Repository

    Xu, Jun

    2016-01-12

    Achieving site selectivity in carbon-hydrogen (C-H) functionalization reactions is a formidable challenge in organic chemistry. Herein, we report a novel approach to activating remote C-H bonds at the C5 position of 8-aminoquinoline through copper-catalyzed sulfonylation under mild conditions. Our strategy shows high conversion efficiency, a broad substrate scope, and good toleration with different functional groups. Furthermore, our mechanistic investigations suggest that a single-electron-transfer process plays a vital role in generating sulfonyl radicals and subsequently initiating C-S cross-coupling. Importantly, our copper-catalyzed remote functionalization protocol can be expanded for the construction of a variety of chemical bonds, including C-O, C-Br, C-N, C-C, and C-I. These findings provide a fundamental insight into the activation of remote C-H bonds, while offering new possibilities for rational design of drug molecules and optoelectronic materials requiring specific modification of functional groups. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Phenylpropanoid Glycoside Analogues: Enzymatic Synthesis, Antioxidant Activity and Theoretical Study of Their Free Radical Scavenger Mechanism

    Science.gov (United States)

    López-Munguía, Agustín; Hernández-Romero, Yanet; Pedraza-Chaverri, José; Miranda-Molina, Alfonso; Regla, Ignacio; Martínez, Ana; Castillo, Edmundo

    2011-01-01

    Phenylpropanoid glycosides (PPGs) are natural compounds present in several medicinal plants that have high antioxidant power and diverse biological activities. Because of their low content in plants (less than 5% w/w), several chemical synthetic routes to produce PPGs have been developed, but their synthesis is a time consuming process and the achieved yields are often low. In this study, an alternative and efficient two-step biosynthetic route to obtain natural PPG analogues is reported for the first time. Two galactosides were initially synthesized from vanillyl alcohol and homovanillyl alcohol by a transgalactosylation reaction catalyzed by Kluyveromyces lactis β-galactosidase in saturated lactose solutions with a 30%–35% yield. To synthesize PPGs, the galactoconjugates were esterified with saturated and unsaturated hydroxycinnamic acid derivatives using Candida antarctica Lipase B (CaL-B) as a biocatalyst with 40%–60% yields. The scavenging ability of the phenolic raw materials, intermediates and PPGs was evaluated by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) method. It was found that the biosynthesized PPGs had higher scavenging abilities when compared to ascorbic acid, the reference compound, while their antioxidant activities were found similar to that of natural PPGs. Moreover, density functional theory (DFT) calculations were used to determine that the PPGs antioxidant mechanism proceeds through a sequential proton loss single electron transfer (SPLET). The enzymatic process reported in this study is an efficient and versatile route to obtain PPGs from different phenylpropanoid acids, sugars and phenolic alcohols. PMID:21674039

  1. Chemical constituents, radical scavenging activity and enzyme inhibitory capacity of fruits from Cotoneaster pannosus Franch.

    Science.gov (United States)

    Les, Francisco; López, Víctor; Caprioli, Giovanni; Iannarelli, Romilde; Fiorini, Dennis; Innocenti, Marzia; Bellumori, Maria; Maggi, Filippo

    2017-05-24

    Cotoneaster pannosus (Rosaceae) is a semievergreen shrub, producing globose dark red pomes, native to China and widely used as an ornamental plant all over the world. Despite its extensive cultivation, little information is available on the chemical composition and biological activities of its fruits. In this work, the analysis of the chemical composition of C. pannosus fruits, in terms of phenolic components, carotenoids and ascorbic acid by HPLC/DAD, HPLC/ESI-MS and MS/MS as well as in terms of macro- and micro-nutrients was performed. The fruits proved to be a good source of shikimic acid and caffeoylquinic acids, whereas β-carotene, pelargonidin-3-O glucoside and cyanidin-3,5-rutinoside gave an important contribution to the color of the fruit. Both the polar and apolar fruit extracts showed noteworthy radical scavenger activity and inhibitory effects against monoamine oxidase A (MAO-A), tyrosinase (TYR) and α-glucosidase, making C. pannosus red pomes a promising candidate ingredient in functional foods and dietary supplements.

  2. Dynamics of activity free radical oxidation reactions in students with cerebral palsy results over the course of the educational process

    Directory of Open Access Journals (Sweden)

    Makarova E.V.

    2012-12-01

    Full Text Available The dynamics of changes activity of reactions is studied freely radical oxidize for students with the consequences of child's cerebral paralysis. 20 students took part in an experiment. Found that the course of study they have more active free radical oxidation reactions and decreases the activity of antiradical protection. Given the use of additional physical activity in aerobic training indicators intracellular antioxidant defense system increased, decreased content of reaction products of lipid peroxidation. However, increased rates of maximum oxygen consumption and increased tolerance of students with cerebral palsy to the consequences of physical activity. It is set that the pathological changes of metabolism for students ground the necessity of application of the differentiated physical loadings. The optimum forms of physical rehabilitation of the aerobic training is the dosed walking, medical swimming, dosed after distance, sometimes and by the corner of getting up pedestrian ascents. Loading is increased due to a volume, but not intensity of exercises.

  3. Free radical scavenging activities measured by electron spin resonance spectroscopy and B16 cell antiproliferative behaviors of seven plants.

    Science.gov (United States)

    Calliste, C A; Trouillas, P; Allais, D P; Simon, A; Duroux, J L

    2001-07-01

    In an effort to discover new antioxidant natural compounds, seven plants that grow in France (most of them in the Limousin countryside) were screened. Among these plants, was the extensively studied Vitis vinifera as reference. For each plant, sequential percolation was realized with five solvents of increasing polarities (hexane, chloroform, ethyl acetate, methanol, and water). Free radical scavenging activities were examined in different systems using electron spin resonance (ESR) spectroscopy. These assays were based on the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH), the hydroxyl radicals generated by a Fenton reaction, and the superoxide radicals generated by the X/XO system. Antiproliferative behavior was studied on B16 melanoma cells. ESR results showed that three plants (Castanea sativa, Filipendula ulmaria, and Betula pendula) possessed, for the most polar fractions (presence of phenolic compounds), high antioxidant activities in comparison with the Vitis vinifera reference. Gentiana lutea was the only one that presented a hydroxyl scavenging activity for the ethyl acetate and chloroform fractions. The antiproliferative test results showed that the same three plants are the most effective, but for the apolar fractions (chloroform and hexane).

  4. Transient receptor potential (TRP) channels as drug targets for diseases of the digestive system

    Science.gov (United States)

    Holzer, Peter

    2011-01-01

    Approximately 20 of the 30 mammalian transient receptor potential (TRP) channel subunits are expressed by specific neurons and cells within the alimentary canal. They subserve important roles in taste, chemesthesis, mechanosensation, pain and hyperalgesia and contribute to the regulation of gastrointestinal motility, absorptive and secretory processes, blood flow, and mucosal homeostasis. In a cellular perspective, TRP channels operate either as primary detectors of chemical and physical stimuli, as secondary transducers of ionotropic or metabotropic receptors, or as ion transport channels. The polymodal sensory function of TRPA1, TRPM5, TRPM8, TRPP2, TRPV1, TRPV3 and TRPV4 enables the digestive system to survey its physical and chemical environment, which is relevant to all processes of digestion. TRPV5 and TRPV6 as well as TRPM6 and TRPM7 contribute to the absorption of Ca2+ and Mg2+, respectively. TRPM7 participates in intestinal pacemaker activity, and TRPC4 transduces muscarinic acetylcholine receptor activation to smooth muscle contraction. Changes in TRP channel expression or function are associated with a variety of diseases/disorders of the digestive system, notably gastro-esophageal reflux disease, inflammatory bowel disease, pain and hyperalgesia in heartburn, functional dyspepsia and irritable bowel syndrome, cholera, hypomagnesemia with secondary hypocalcemia, infantile hypertrophic pyloric stenosis, esophageal, gastrointestinal and pancreatic cancer, and polycystic liver disease. These implications identify TRP channels as promising drug targets for the management of a number of gastrointestinal pathologies. As a result, major efforts are put into the development of selective TRP channel agonists and antagonists and the assessment of their therapeutic potential. PMID:21420431

  5. New insights into the aquatic photochemistry of fluoroquinolone antibiotics: Direct photodegradation, hydroxyl-radical oxidation, and antibacterial activity changes

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Linke; Na, Guangshui [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China); Zhang, Siyu [Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016 (China); Li, Kai [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China); Zhang, Peng, E-mail: pzhang@nmemc.org.cn [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China); Ren, Honglei; Yao, Ziwei [Key Laboratory for Ecological Environment in Coastal Areas (SOA), National Marine Environmental Monitoring Center, Dalian 116023 (China)

    2015-09-15

    The ubiquity and photoreactivity of fluoroquinolone antibiotics (FQs) in surface waters urge new insights into their aqueous photochemical behavior. This study concerns the photochemistry of 6 FQs: ciprofloxacin, danofloxacin, levofloxacin, sarafloxacin, difloxacin and enrofloxacin. Methods were developed to calculate their solar direct photodegradation half-lives (t{sub d,E}) and hydroxyl-radical oxidation half-lives (t{sub ·OH,E}) in sunlit surface waters. The t{sub d,E} values range from 0.56 min to 28.8 min at 45° N latitude, whereas t{sub ·OH,E} ranges from 3.24 h to 33.6 h, suggesting that most FQs tend to undergo fast direct photolysis rather than hydroxyl-radical oxidation in surface waters. However, a case study for levofloxacin and sarafloxacin indicated that the hydroxyl-radical oxidation induced risky photochlorination and resulted in multi-degradation pathways, such as piperazinyl hydroxylation and clearage. Changes in the antibacterial activity of FQs caused by photodegradation in various waters were further examined using Escherichia coli, and it was found that the activity evolution depended on primary photodegradation pathways and products. Primary intermediates with intact FQ nuclei retained significant antibacterial activity. These results are important for assessing the fate and risk of FQs in surface waters. - Highlights: • It is first reported on hydroxyl-radical oxidation of 6 fluoroquinolone antibiotics. • Methods were developed to assess photolysis and oxidation fate in surface waters. • The neutral form reacted faster with hydroxyl radical than protonated forms. • The main oxidation intermediates and transformation pathways were clarified. • The antibacterial activity changes depend on dominant photolysis pathways.

  6. New insights into the aquatic photochemistry of fluoroquinolone antibiotics: Direct photodegradation, hydroxyl-radical oxidation, and antibacterial activity changes

    International Nuclear Information System (INIS)

    Ge, Linke; Na, Guangshui; Zhang, Siyu; Li, Kai; Zhang, Peng; Ren, Honglei; Yao, Ziwei

    2015-01-01

    The ubiquity and photoreactivity of fluoroquinolone antibiotics (FQs) in surface waters urge new insights into their aqueous photochemical behavior. This study concerns the photochemistry of 6 FQs: ciprofloxacin, danofloxacin, levofloxacin, sarafloxacin, difloxacin and enrofloxacin. Methods were developed to calculate their solar direct photodegradation half-lives (t d,E ) and hydroxyl-radical oxidation half-lives (t ·OH,E ) in sunlit surface waters. The t d,E values range from 0.56 min to 28.8 min at 45° N latitude, whereas t ·OH,E ranges from 3.24 h to 33.6 h, suggesting that most FQs tend to undergo fast direct photolysis rather than hydroxyl-radical oxidation in surface waters. However, a case study for levofloxacin and sarafloxacin indicated that the hydroxyl-radical oxidation induced risky photochlorination and resulted in multi-degradation pathways, such as piperazinyl hydroxylation and clearage. Changes in the antibacterial activity of FQs caused by photodegradation in various waters were further examined using Escherichia coli, and it was found that the activity evolution depended on primary photodegradation pathways and products. Primary intermediates with intact FQ nuclei retained significant antibacterial activity. These results are important for assessing the fate and risk of FQs in surface waters. - Highlights: • It is first reported on hydroxyl-radical oxidation of 6 fluoroquinolone antibiotics. • Methods were developed to assess photolysis and oxidation fate in surface waters. • The neutral form reacted faster with hydroxyl radical than protonated forms. • The main oxidation intermediates and transformation pathways were clarified. • The antibacterial activity changes depend on dominant photolysis pathways

  7. Radical scavenging and iron-chelating activities of some greens used as traditional dishes in Mediterranean diet.

    Science.gov (United States)

    El, Sedef Nehir; Karakaya, Sibel

    2004-02-01

    This study aimed at evaluating the antioxidative activity of nine different families of greens. Raphanus raphanistrum (wild radish), Anchusa azurea (bugloss), Daucus carota (wild carrot), Sonchus oleraceus (sowthistle), Papaver rhoeas (corn poppy), Malva sylvestris (blue mallow), Foeniculum vulgare (fennel), Cichorium intybus (chicory) and Salicornia europaea (jointed glasswort) are native to the Mediterranean and are commonly consumed as a salad or an ingredient in some recipes. The antioxidative activities, including the radical scavenging effects, inhibition of hydrogen peroxide (H(2)O(2)), and Fe(2+)-chelating activity, were studied. All samples showed antioxidant activity as a radical scavenger in the experiment using the DPPH* radical. The ratio between the slopes of the kinetic model was used to compare antioxidant efficiency of different greens. Greens also possessed antioxidative activity toward H(2)O(2). Especially, greens exhibited a marked scavenging effect on H(2)O(2) at 0.2 g/ml concentration. The Fe(2+) ion-chelating activities of the samples except jointed glasswort were greater than 70%. The antioxidant activity of samples with different methods based on the inhibition of different reactions could not be compared. The current dietary guidelines include recommendations for an increase in the consumption of plant foods. Greens should provide an optimal supply of antioxidant substances in the diet.

  8. Pigment and amylase production in Penicillium sp NIOM-02 and its radical scavenging activity

    Digital Repository Service at National Institute of Oceanography (India)

    Dhale, M.A.; VijayRaj, A.S.

    Penicillium sp NIOM-02 was isolated from the marine sediment, produced red pigment. The pigment extracted from this fungus scavenged 2, 2-diphenyl-1-pycrylhydrazyl (DPPH) radical. Penicillium sp NIOM-02 grown in media containing corn steep liquor...

  9. Metabolic profiles and free radical scavenging activity of Cordyceps bassiana fruiting bodies according to developmental stage.

    Directory of Open Access Journals (Sweden)

    Sun-Hee Hyun

    Full Text Available The metabolic profiles of Cordyceps bassiana according to fruiting body developmental stage were investigated using gas chromatography-mass spectrometry. We were able to detect 62 metabolites, including 48 metabolites from 70% methanol extracts and 14 metabolites from 100% n-hexane extracts. These metabolites were classified as alcohols, amino acids, organic acids, phosphoric acids, purine nucleosides and bases, sugars, saturated fatty acids, unsaturated fatty acids, or fatty amides. Significant changes in metabolite levels were found according to developmental stage. Relative levels of amino acids, purine nucleosides, and sugars were higher in development stage 3 than in the other stages. Among the amino acids, valine, isoleucine, lysine, histidine, glutamine, and aspartic acid, which are associated with ABC transporters and aminoacyl-tRNA biosynthesis, also showed higher levels in stage 3 samples. The free radical scavenging activities, which were significantly higher in stage 3 than in the other stages, showed a positive correlation with purine nucleoside metabolites such as adenosine, guanosine, and inosine. These results not only show metabolic profiles, but also suggest the metabolic pathways associated with fruiting body development stages in cultivated C. bassiana.

  10. Lipid metabolites with free-radical scavenging activity from Euphorbia helioscopia L.

    Science.gov (United States)

    Cateni, F; Zilic, J; Altieri, T; Zacchigna, M; Procida, G; Gaggeri, R; Rossi, D; Collina, S

    2014-07-01

    The methanolic extract of the plant Euphorbia helioscopia L. exhibited an interesting free-radical scavenging activity. From the aerial parts of Euphorbia helioscopia L. (Euphorbiaceae), a complex mixture of seven cerebrosides together with glucoclionasterol, a digalactosyldiacylglycerol and a diacylmonogalactosylglycerol were identified. The structures of the cerebrosides were characterized as 1-O-β-D-glucosides of phytosphingosines, which comprised (2S, 3S, 4E, 8E)-2-amino-4(E),8(E)-octadecadiene-1,3-diol, (2S, 3S, 4E, 8Z)-2-amino-4(E),8(Z)-octadecadiene-1,3-diol, (2S, 3S, 4R, 8Z)-2-amino-8(Z)-octadecene-1,3,4-triol as long chain bases with seven 2-hydroxy fatty acids of varying chain lengths (C16, C24:1, C26:1, C24, C26, C28:1) linked to the amino group. The glycosylglycerides were characterized as (2S)-2,3-O-di-(9,12,15-octadecatrienoyl)-glyceryl-6-O-(α-D-galactopyranosyl)-β-D-galactopyranoside and (2S)-2,3-O-di-(9,12,15-octadecatrienoyl)-glyceryl-1-O-β-D-galactopyranoside. The structures were established on the basis of spectroscopic data and chemical reactions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Quantitative Structure--Activity Relationship (QSAR) for the Oxidation of Trace Organic Contaminants by Sulfate Radical.

    Science.gov (United States)

    Xiao, Ruiyang; Ye, Tiantian; Wei, Zongsu; Luo, Shuang; Yang, Zhihui; Spinney, Richard

    2015-11-17

    The sulfate radical anion (SO4•–) based oxidation of trace organic contaminants (TrOCs) has recently received great attention due to its high reactivity and low selectivity. In this study, a meta-analysis was conducted to better understand the role of functional groups on the reactivity between SO4•– and TrOCs. The results indicate that compounds in which electron transfer and addition channels dominate tend to exhibit a faster second-order rate constants (kSO4•–) than that of H–atom abstraction, corroborating the SO4•– reactivity and mechanisms observed in the individual studies. Then, a quantitative structure activity relationship (QSAR) model was developed using a sequential approach with constitutional, geometrical, electrostatic, and quantum chemical descriptors. Two descriptors, ELUMO and EHOMO energy gap (ELUMO–EHOMO) and the ratio of oxygen atoms to carbon atoms (#O:C), were found to mechanistically and statistically affect kSO4•– to a great extent with the standardized QSAR model: ln kSO4•– = 26.8–3.97 × #O:C – 0.746 × (ELUMO–EHOMO). In addition, the correlation analysis indicates that there is no dominant reaction channel for SO4•– reactions with various structurally diverse compounds. Our QSAR model provides a robust predictive tool for estimating emerging micropollutants removal using SO4•– during wastewater treatment processes.

  12. Radical scavenging activity of some natural tropolones by density functional theory

    Directory of Open Access Journals (Sweden)

    A. G. Al-Sehemi

    2017-07-01

    Full Text Available The ground state neutral geometries of some natural tropolones, i.e. stipitatonic acid (AF1, stipitalide (AF2, stipitaldehydic acid (AF3 and methyl stipitate (AF4 have been optimized by using Density Functional Theory (DFT at B3LYP/6-31G*, B3LYP/6-31G**, B3LYP/6-31+G* and B3LYP/6-31+G** levels of theory. The excited state geometries of AF1-AF4 were optimized by adopting the Time Dependent Density Functional Theory (TDDFT at the same levels of theory. The frequencies and cation species of AF1-AF4 were also computed at all the above mentioned levels of theory. We shed light on the electro-optical and molecular properties, e.g. energy gaps, highest occupied molecular orbitals, lowest unoccupied molecular orbitals, absorption wavelengths, electronegativity (χ, hardness (η, electrophilicity (ω, softness (S, electrophilicity index (ωi and the radical scavenging activity (RSA. Hydrogen atom transfer (HAT and one-electron transfer mechanisms have been discussed to shed light on the RSA. The smallest ionization potential and bond dissociation energy of AF4 are revealing that this compound would have more RSA than those of other counterparts.

  13. Potential Superoxide Anion Radical Scavenging Activity of Doum Palm ( Hyphaene thebaica L. Leaves Extract

    Directory of Open Access Journals (Sweden)

    Mohamed M. Al-Azizi

    2008-08-01

    Full Text Available The antioxidant activity of the aqueous ethanolic extract of Doum leaves, Hyphaene thebaica L. (Palmae, was studied. Data obtained showed that the extract scavenged superoxide anion radicals ( IC 50=1602 µg/ml in a dose dependant manner using xanthine/hypoxanthine oxidase assay. Four major flvonoidal compounds were identified by LC/SEI as; Quercetin glucoside , Kaempferol rhamnoglucoside, Dimethyoxyquercetin rhamnoglucoside . While , further in-depth phytochemical investigation of this extract lead to the isolation and identification of fourteen compounds ;their structures were elucidated based upon the interpretation of their spectral data(UV, 1H, 13C NMR and ESI/MS as; 8-C-β-D-glucopyranosyl-5, 7, 4`-trihydroxyflavone (vitexin 1, 6-C-β-D-glucopyranosyl-5, 7, 4`-trihydroxyflavone (iso-vitexin 2, quercetin 3-O-β- 4C 1-D-glucopyranoside 3, gallic acid 4, quercetin 7-O-β- 4C 1-D-glucoside 5, luteolin 7-O-β- 4C 1-D-glucoside 6, tricin 5 O-β- 4C 1-D-glucoside 7, 7, 3` dimethoxy quercetin 3-O-[6''-O-α-L-rhamnopyranosyl]-β-D-gluco-pyranoside (Rhamnazin 3-O-rutinoside 8, kaempferol-3-O-[6''-O-α- L-rhamnopyranosyl]-β- D-glucopyranoside (nicotiflorin 9, apigenin 10, luteolin 11, tricin 12, quercetin 13 and kaempferol 14

  14. Formation of hydroxyl radicals contributes to the bactericidal activity of ciprofloxacin against Pseudomonas aeruginosa biofilms.

    Science.gov (United States)

    Jensen, Peter Ø; Briales, Alejandra; Brochmann, Rikke P; Wang, Hengzhuang; Kragh, Kasper N; Kolpen, Mette; Hempel, Casper; Bjarnsholt, Thomas; Høiby, Niels; Ciofu, Oana

    2014-04-01

    Antibiotic-tolerant, biofilm-forming Pseudomonas aeruginosa has long been recognized as a major cause of chronic lung infections of cystic fibrosis patients. The mechanisms involved in the activity of antibiotics on biofilm are not completely clear. We have investigated whether the proposed induction of cytotoxic hydroxyl radicals (OH˙) during antibiotic treatment of planktonically grown cells may contribute to action of the commonly used antibiotic ciprofloxacin on P. aeruginosa biofilms. For this purpose, WT PAO1, a catalase deficient ΔkatA and a ciprofloxacin resistant mutant of PAO1 (gyrA), were grown as biofilms in microtiter plates and treated with ciprofloxacin. Formation of OH˙ and total amount of reactive oxygen species (ROS) was measured and viability was estimated. Formation of OH˙ and total ROS in PAO1 biofilms treated with ciprofloxacin was shown but higher levels were measured in ΔkatA biofilms, and no ROS production was seen in the gyrA biofilms. Treatment with ciprofloxacin decreased the viability of PAO1 and ΔkatA biofilms but not of gyrA biofilms. Addition of thiourea, a OH˙ scavenger, decreased the OH˙ levels and killing of PAO1 biofilm. Our study shows that OH˙ is produced by P. aeruginosa biofilms treated with ciprofloxacin, which may contribute to the killing of biofilm subpopulations. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  15. Long-lived radicals produced by γ-irradiation or vital activity in plants, animals, cells, and protein solution: their observation and inhomogeneous decay dynamics

    International Nuclear Information System (INIS)

    Miyazaki, Tetsuo; Morikawa, Akiyuki; Kumagai, Jun; Ikehata, Masateru; Koana, Takao; Kikuchi, Shoshi

    2002-01-01

    Long-lived radicals produced by γ-irradiation or vital activity in plants, animals, cells, and protein (albumin) solution were studied by electron spin resonance spectroscopy. Long-lived radicals produced by vital activity exist in biological systems, such as plants, animals, and cells, in the range of 0.1-20 nmol g -1 . Since vital organs keep the radicals at a constant concentration, the radicals are probably related to life conservation. Long-lived radicals are also produced by γ-irradiation of cells or protein solution. The radicals decay after death of living things or after γ-irradiation. We found that the decay dynamics in all biological systems can be expressed by the same kinetic equation of an inhomogeneous reaction

  16. Changes in the amino acid profiles and free radical scavenging activities of Tenebrio molitor larvae following enzymatic hydrolysis.

    Science.gov (United States)

    Tang, Yujiao; Debnath, Trishna; Choi, Eun-Ju; Kim, Young Wook; Ryu, Jung Pyo; Jang, Sejin; Chung, Sang Uk; Choi, Young-Jin; Kim, Eun-Kyung

    2018-01-01

    Tenebrio molitor (T. molitor) larvae provide food at low environmental cost and contribute positively to livelihoods. In this research, we compared the amino acids compositions and antioxidant activities of various extracts of T. molitor to enhance their quality as food. For the comparison, distilled water extracts, enzymatic hydrolysates, and condensed enzymatic hydrolysates of T. molitor larvae were prepared. Their amino acids (AAs) profiles and antioxidant activities, including ferric-reducing antioxidant power, oxygen radical absorption capacity, and DPPH, hydroxyl radical, and hydrogen peroxide radical scavenging properties assay were analyzed. DW extracts had the lowest AAs contents and antioxidant activity compared with enzymatic extracts. Condensed hydrolysates with a combination of alcalase and flavourzyme (C-A+F) exhibited the highest levels of total free AAs (11.1759 g/100 g). C-A+F produced higher total hydrolyzed AAs (32.5292 g/100 g) compared with the other groups. The C-A+F possessed the strongest antioxidant activity. Notably, the antioxidant activities of the hydrolysates and the total hydrolyzed AAs amount were correlated. Taken together, our findings showed that C-A+F was a promising technique for obtaining extracts of T. molitor larvae with antioxidant activity as potential nutritious functional food.

  17. The oxygen-centered radicals scavenging activity of sulfasalazine and its metabolites. A direct protection of the bowel.

    Science.gov (United States)

    Prónai, L; Yukinobu, I; Láng, I; Fehér, J

    1992-01-01

    Oxygen-centered radicals, such as superoxide (O2-) and hydroxyl radicals (.OH) generated by phagocytes have been suggested to be involved in the pathogenesis of chronic inflammations of the bowel, such as Crohn's disease and colitis ulcerosa. Recently, sulfasalazine (SASP) and its metabolites have been reported to exert their effects as a direct scavenger of oxygen-centered radicals in the bowel. To scavenge oxygen-centered radicals in vivo, however, SASP and its metabolites have to react with O2- and/or .OH in vitro very rapidly, furthermore they have to reach an appropriate (possible millimolar) concentration range at the site of inflammation. To test this possibility, we investigated the direct O2- and .OH scavenging activity of SASP and its metabolites using the specific electron paramagnetic resonance/spin trapping method, and we compared the 50% inhibition rates of SASP and its metabolites with their known concentrations in the bowel and in the human plasma. It was found that SASP and its metabolites, such as 5-amino-salicylic acid (5-ASA), and acetyl-5-amino-salicylic acid (AC-5-ASA), but not sulfapyridine (SP) and acetyl-sulfapyridine (Ac-SP) have a direct O2- and .OH scavenging activity in vitro systems. Among the compounds, SASP and 5-ASA can reach a concentration which is appropriate to scavenge oxygen-centered radicals in the bowel but not in the human plasma. It was concluded that the in vivo antiinflammatory effects of SASP and its metabolites are, at least partly, due to the direct oxygen-centered scavenging activity of these drugs.

  18. Surface–active bismuth ferrite as superior peroxymonosulfate activator for aqueous sulfamethoxazole removal: Performance, mechanism and quantification of sulfate radical

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Wen-Da, E-mail: wdoh@ntu.edu.sg [Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141 (Singapore); Division of Environmental and Water Resources Engineering, School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Dong, Zhili [Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141 (Singapore); School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Ronn, Goei [Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141 (Singapore); Lim, Teik-Thye, E-mail: cttlim@ntu.edu.sg [Nanyang Environment and Water Research Institute (NEWRI), Nanyang Technological University, 1 Cleantech Loop, CleanTech One, Singapore 637141 (Singapore); Division of Environmental and Water Resources Engineering, School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2017-03-05

    Highlights: • Bi{sub 2}Fe{sub 4}O{sub 9} nanoplates (BF-nP) was synthesized via a hydrothermal method. • BF-nP was used as peroxymonosulfate (PMS) activator for sulfamethoxazole (SMX) removal. • The Fe{sup 3+}/Fe{sup 2+} and Bi{sup 3+}/Bi{sup 5+} couples are responsible for PMS activation. • The sulfate radical concentration was quantified through benzoquinone detection. - Abstract: A surface–active Bi{sub 2}Fe{sub 4}O{sub 9} nanoplates (BF–nP) was prepared using a facile hydrothermal protocol for sulfamethoxazole (SMX) removal via peroxymonosulfate (PMS). The catalytic activity of BF–nP was superior to other catalysts with the following order of performance: BF–nP > Bi{sub 2}Fe{sub 4}O{sub 9} (nanocubes) >> Co{sub 3}O{sub 4} > Fe{sub 2}O{sub 3} (low temperature co–precipitation method) > Fe{sub 2}O{sub 3} (hydrothermal method) ∼ Bi{sub 2}O{sub 3} ∼ Bi{sup 3+} ∼ Fe{sup 3+}. The empirical relationship of the apparent rate constant (k{sub app}), BF–nP loading and PMS dosage can be described as follows: k{sub app} = 0.69[BF–nP]{sup 0.6}[PMS]{sup 0.4} (R{sup 2} = 0.98). The GC–MS study suggests that the SMX degradation proceed mainly through electron transfer reaction. The XPS study reveals that the interconversion of Fe{sup 3+}/Fe{sup 2+} and Bi{sup 3+}/Bi{sup 5+} couples are responsible for the enhanced PMS activation. The radical scavenging study indicates that SO{sub 4}·{sup −} is the dominant reactive radical (>92% of the total SMX degradation). A method to quantify SO{sub 4}·{sup −} in the heterogeneous Bi{sub 2}Fe{sub 4}O{sub 9}/PMS systems based on the quantitation of benzoquinone, which is the degradation byproduct of p–hydroxybenzoic acid and SO{sub 4}·{sup −}, is proposed. It was found that at least 7.8 ± 0.1 μM of SO{sub 4}·{sup −} was generated from PMS during the BF–nP/PMS process (0.1 g L{sup −1}, 0.40 mM PMS, natural pH). The Bi{sub 2}Fe{sub 4}O{sub 9} nanoplates has a remarkable potential for use as a

  19. Radical scavenging activities of Rio Red grapefruits and Sour orange fruit extracts in different in vitro model systems.

    Science.gov (United States)

    Jayaprakasha, G K; Girennavar, Basavaraj; Patil, Bhimanagouda S

    2008-07-01

    Antioxidant fractions from two different citrus species such as Rio Red (Citrus paradise Macf.) and Sour orange (Citrus aurantium L.) were extracted with five different polar solvents using Soxhlet type extractor. The total phenolic content of the extracts was determined by Folin-Ciocalteu method. Ethyl acetate extract of Rio Red and Sour orange was found to contain maximum phenolics. The dried fractions were screened for their antioxidant activity potential using in vitro model systems such as 1,1-diphenyl-2-picryl hydrazyl (DPPH), phosphomolybdenum method and nitroblue tetrazolium (NBT) reduction at different concentrations. The methanol:water (80:20) fraction of Rio Red showed the highest radical scavenging activity 42.5%, 77.8% and 92.1% at 250, 500 and 1000 ppm, respectively, while methanol:water (80:20) fraction of Sour orange showed the lowest radical scavenging activity at all the tested concentrations. All citrus fractions showed good antioxidant capacity by the formation of phosphomolybdenum complex at 200 ppm. In addition, superoxide radical scavenging activity was assayed using non-enzymatic (NADH/phenaxine methosulfate) superoxide generating system. All the extracts showed variable superoxide radical scavenging activity. Moreover, methanol:water (80:20) extract of Rio Red and methanol extract of Sour orange exhibited marked reducing power in potassium ferricyanide reduction method. The data obtained using above in vitro models clearly establish the antioxidant potential of citrus fruit extracts. However, comprehensive studies need to be conducted to ascertain the in vivo bioavailability, safety and efficacy of such extracts in experimental animals. To the best of our knowledge, this is the first report on antioxidant activity of different polar extracts from Rio Red and Sour oranges.

  20. Improved Mechanical Performance Fracture Properties and Reliability of Radical-Cured Thermosets

    Energy Technology Data Exchange (ETDEWEB)

    Redline, Erica Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bolintineanu, Dan S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lane, J. Matthew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stevens, Mark J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Alam, Todd M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Celina, Mathias C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-10-01

    The aim of this study was to alter polymerization chemistry to improve network homogeneity in free-radical crosslinked systems. It was hypothesized that a reduction in heterogeneity of the network would lead to improved mechanical performance. Experiments and simulations were carried out to investigate the connection between polymerization chemistry, network structure and mechanical properties. Experiments were conducted on two different monomer systems - the first is a single monomer system, urethane dimethacrylate (UDMA), and the second is a two-monomer system consisting of bisphenol A glycidyl dimethacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) in a ratio of 70/30 BisGMA/TEGDMA by weight. The methacrylate systems were crosslinked using traditional radical polymeriza- tion (TRP) with azobisisobutyronitrile (AIBN) or benzoyl peroxide (BPO) as an initiator; TRP systems were used as the control. The monomers were also cross-linked using activator regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) as a type of controlled radical polymerization (CRP). FTIR and DSC were used to monitor reac- tion kinetics of the systems. The networks were analyzed using NMR, DSC, X-ray diffraction (XRD), atomic force microscopy (AFM), and small angle X-ray scattering (SAXS). These techniques were employed in an attempt to quantify differences between the traditional and controlled radical polymerizations. While a quantitative methodology for characterizing net- work morphology was not established, SAXS and AFM have shown some promising initial results. Additionally, differences in mechanical behavior were observed between traditional and controlled radical polymerized thermosets in the BisGMA/TEGDMA system but not in the UDMA materials; this finding may be the result of network ductility variations between the two materials. Coarse-grained molecular dynamics simulations employing a novel model of the CRP reaction were carried out for

  1. Radical-Scavenging Activity of Dietary Phytophenols in Combination with co-Antioxidants Using the Induction Period Method

    Directory of Open Access Journals (Sweden)

    Seiichiro Fujisawa

    2011-12-01

    Full Text Available The radical-scavenging activity of dietary phytophenols has been investigated by many researches due to their antioxidant, anti-inflammatory and anticancer property but the radical-scavenging effect of 2-phytophenol and the phytophenol:co-antioxidants, vitamin C and thiol combination under nearly anaerobic conditions still remains unknown. The radical-scavenging activity for seventeen phytophenols and for six synthetic phenols (positive controls was investigated using the induction period method in the polymerization of methyl methacrylates (MMA initiated by thermal decomposition of benzoyl peroxide (BPO by monitoring differential scanning calorimetery (DSC. The kinh for the phytophenols was likely with the range 0.5 × 103 M−1s−1−2.2 × 103 M−1s−1, whereas that for synthetic phenols, hydroquinone and galvinoxyl, was with the range 7 × 103 M−1s−1−8 × 103 M−1s−1. Also, the additive scavenging effect of the (−-epigallocatechin (EGC:(−-epicatechin (EC and the (+-catechin:epicatechin (EC combination was observed at 1:1 molar ratio, whereas that of the EC:quercetin combination showed the cancel (prooxidative effect. Furthermore, the EGC:ASDB (L-ascorbyl 2,6-dibutylate or 2-ME (2-mercaptoethanol combination showed the prooxidative effect. Such enhancement of prooxidation in the combination may increase their toxic effects due to their cooxidation. Also, the synergic, additive or cancel effects of the flavonoid:vitamins E combination on the induction period in the BPO (a PhCOO* radical and 2,2′-azobisisobutyronitrile (AIBN, an R* radical systems are discussed.

  2. Oxygen activation at the plasma membrane: relation between superoxide and hydroxyl radical production by isolated membranes.

    Science.gov (United States)

    Heyno, Eiri; Mary, Véronique; Schopfer, Peter; Krieger-Liszkay, Anja

    2011-07-01

    Production of reactive oxygen species (hydroxyl radicals, superoxide radicals and hydrogen peroxide) was studied using EPR spin-trapping techniques and specific dyes in isolated plasma membranes from the growing and the non-growing zones of hypocotyls and roots of etiolated soybean seedlings as well as coleoptiles and roots of etiolated maize seedlings. NAD(P)H mediated the production of superoxide in all plasma membrane samples. Hydroxyl radicals were only produced by the membranes of the hypocotyl growing zone when a Fenton catalyst (FeEDTA) was present. By contrast, in membranes from other parts of the seedlings a low rate of spontaneous hydroxyl radical formation was observed due to the presence of small amounts of tightly bound peroxidase. It is concluded that apoplastic hydroxyl radical generation depends fully, or for the most part, on peroxidase localized in the cell wall. In soybean plasma membranes from the growing zone of the hypocotyl pharmacological tests showed that the superoxide production could potentially be attributed to the action of at least two enzymes, an NADPH oxidase and, in the presence of menadione, a quinone reductase.

  3. FREE RADICAL SCAVENGING CAPACITY OF PAPAVER SOMNIFERUM L. AND DETERMINATION OF PHARMACOLOGICALLY ACTIVE ALKALOIDS USING CAPILLARY ELECTROPHORESIS

    Directory of Open Access Journals (Sweden)

    Marián Valko

    2012-02-01

    Full Text Available The free radical generation is related to the oxidation process in biological systems as well as in foods. It was found that oxidation is affected by antioxidants that can act as radical scavengers. Objective of the present work was to study the free radical scavenging capacity of opium poppy (Papaver somniferum L. extract by using the DPPH test and to verify the suitability of the micellar electrokinetic capillary chromatography (MEKC technique for analytical assessment and determination of three major poppy alkaloids (thebaine, morphine and papaverine. Because of its generally high separation efficiency, the MEKC is successfully used for analytical evaluation of biologically active substances usually without special claims for sample preparation. The results of DPPH test have shown that poppy contains components capable of terminating free radicals. We have confirmed that nature of the solvent used for the electrophoretic medium in MEKC has a strong influence on the separation efficiency. In our experiments, the most effective solvent was mixture of water to acetonitrile (ratio 4:6.

  4. Radical-Scavenging Activity of a Sunscreen Enriched by Antioxidants Providing Protection in the Whole Solar Spectral Range.

    Science.gov (United States)

    Souza, Carla; Maia Campos, Patrícia; Schanzer, Sabine; Albrecht, Stephanie; Lohan, Silke B; Lademann, Jürgen; Darvin, Maxim E; Meinke, Martina C

    2017-01-01

    The main reason for extrinsic skin aging is the negative action of free radicals. The formation of free radicals in the skin has been associated with ultraviolet (UV) exposure and also to visible (VIS) and near-infrared (NIR) irradiations. The aim of the present study was to evaluate the efficacy of a sunscreen in the whole solar range. The radical-scavenging activity of a sunscreen in the UV, VIS, and NIR ranges was evaluated using electron paramagnetic resonance spectroscopy. Ex vivo penetration profiles were determined using confocal Raman microscopy on porcine ear skin at different time points after application. Compared to the untreated skin, the sunscreen decreased the skin radical formation in the UV and VIS regions. Additional protection in the VIS and NIR ranges was observed for the sunscreen containing antioxidants (AO). The penetration depth of the cream was less than 11.2 ± 3.0 µm for all time points. A sunscreen containing AO improved the photoprotection in the VIS and NIR ranges. The sunscreen was retained in the stratum corneum. Therefore, these results show the possibility of the development of effective and safer sunscreen products. © 2017 S. Karger AG, Basel.

  5. Radiolabelled neurotensin analogues. I. Solid phase synthesis and biological characterization of [Trp11]-neurotensin precursor of an ionidated ligand

    International Nuclear Information System (INIS)

    Labbe-Jullie, C.; Granier, C.; Van Rietschoten, J.; Kitabgi, P.; Vincent, J.P.

    1983-01-01

    In order to generate highly labelled neurotensin analogues, synthesis has been performed of two types of precursors, one for iodination and one for tritiation. Iodination of native neurotensin occurs on both tyrosines in position 3 and 11 and thus affects greatly its binding capacities. Synthesis and chemical characterization of [Trp 11 ]-neurotensin are described which can be iodinated without loss of activity. Synthesis was by solid phase procedure on an experimental support, Pab-resin, α-(4-chloromethylphenylacetamido)-benzyl copoly (styrene 1 per cent divinylbenzene). The homogeneity of [Trp 11 ]-neurotensin was assessed by amino acid analysis, high voltage paper electrophoresis and high pressure liquid chromatography. Iodination by the lactoperoxydase method gave iodo-[Trp 11 ]-neurotensin iodinated on the Tyr 3 . Compared to neurotensin, potency of [Trp 11 ]-neurotensin and of iodo-[Trp 11 ]-neurotensin in competitive inhibition of tritiated neurotensin binding to rat brain synaptic membranes was respectively 93 per cent and 80 per cent, but in the biological test on the contractility of isolated longitudinal smooth muscle strips of guinea pig the relative activity for the two analogues was of 10 per cent [fr

  6. Prediction of radical scavenging activities of anthocyanins applying adaptive neuro-fuzzy inference system (ANFIS) with quantum chemical descriptors.

    Science.gov (United States)

    Jhin, Changho; Hwang, Keum Taek

    2014-08-22

    Radical scavenging activity of anthocyanins is well known, but only a few studies have been conducted by quantum chemical approach. The adaptive neuro-fuzzy inference system (ANFIS) is an effective technique for solving problems with uncertainty. The purpose of this study was to construct and evaluate quantitative structure-activity relationship (QSAR) models for predicting radical scavenging activities of anthocyanins with good prediction efficiency. ANFIS-applied QSAR models were developed by using quantum chemical descriptors of anthocyanins calculated by semi-empirical PM6 and PM7 methods. Electron affinity (A) and electronegativity (χ) of flavylium cation, and ionization potential (I) of quinoidal base were significantly correlated with radical scavenging activities of anthocyanins. These descriptors were used as independent variables for QSAR models. ANFIS models with two triangular-shaped input fuzzy functions for each independent variable were constructed and optimized by 100 learning epochs. The constructed models using descriptors calculated by both PM6 and PM7 had good prediction efficiency with Q-square of 0.82 and 0.86, respectively.

  7. Prediction of Radical Scavenging Activities of Anthocyanins Applying Adaptive Neuro-Fuzzy Inference System (ANFIS with Quantum Chemical Descriptors

    Directory of Open Access Journals (Sweden)

    Changho Jhin

    2014-08-01

    Full Text Available Radical scavenging activity of anthocyanins is well known, but only a few studies have been conducted by quantum chemical approach. The adaptive neuro-fuzzy inference system (ANFIS is an effective technique for solving problems with uncertainty. The purpose of this study was to construct and evaluate quantitative structure-activity relationship (QSAR models for predicting radical scavenging activities of anthocyanins with good prediction efficiency. ANFIS-applied QSAR models were developed by using quantum chemical descriptors of anthocyanins calculated by semi-empirical PM6 and PM7 methods. Electron affinity (A and electronegativity (χ of flavylium cation, and ionization potential (I of quinoidal base were significantly correlated with radical scavenging activities of anthocyanins. These descriptors were used as independent variables for QSAR models. ANFIS models with two triangular-shaped input fuzzy functions for each independent variable were constructed and optimized by 100 learning epochs. The constructed models using descriptors calculated by both PM6 and PM7 had good prediction efficiency with Q-square of 0.82 and 0.86, respectively.

  8. 1,1-Diphenyl-2-picrylhydrazyl radical-scavenging compounds from soybean miso and antiproliferative activity of isoflavones from soybean miso toward the cancer cell lines.

    Science.gov (United States)

    Hirota, A; Taki, S; Kawaii, S; Yano, M; Abe, N

    2000-05-01

    Guided by their DPPH radical-scavenging activity, nine compounds were isolated from soybean miso. Of these, 8-hydroxydaidzein, 8-hydroxygenistein and syringic acid had as high DPPH radical-scavenging activity as that of alpha-tocopherol. The antiproliferative activity of four of the isolated isoflavones toward three cancer cell lines was examined. 8-Hydroxygenistein showed the highest activity (IC50=5.2 microM) toward human promyelocytic leukemia cells (HL-60).

  9. Evaluation of antimalarial, free-radical-scavenging and insecticidal activities of Artemisia scoparia and A. Spicigera, Asteraceae

    Directory of Open Access Journals (Sweden)

    Fariba H. Afshar

    2011-12-01

    Full Text Available Artemisia species (Asteraceae, widespread throughout the world, are a group of important medicinal plants. The extracts of two medicinal plants of this genus, Artemisia scoparia Waldst. & Kit. and A. spicigera C. Koch, were evaluated for potential antimalarial, free-radical-scavenging and insecticidal properties, using the heme biocrystallisation and inhibition assay, the DPPH assay and the contact toxicity bioassay using the pest Tribolium castaneum, respectively. The methanol extracts of both species showed strong free-radical-scavenging activity and the RC50 values were 0.0317 and 0.0458 mg/mL, respectively, for A. scoparia and A. spicigera. The dichloromethane extracts of both species displayed a moderate level of potential antimalarial activity providing IC50 at 0.778 and 0.999 mg/mL for A. scoparia and A. spicigera, respectively. Both species of Artemisia showed insecticidal properties. However, A. spicigera was more effective than A. scoparia.

  10. Antioxidant and Free Radical Scavenging Activity of Trigonella foenum-graecum L, Murraya koenigii , Coriandrum sativum and Centella asiatica

    Directory of Open Access Journals (Sweden)

    Sanghamitra Dutta

    2016-04-01

    Full Text Available Antioxidants are naturally occurring substances that combat oxidative damage in biological entities. An antioxidant achieves this by slowing or preventing the oxidation process that can damage cells in the body. It does this by getting oxidized itself in place of the cells. The aim of the present study was to evaluate the in vitro antioxidant and free radical scavenging activities of aqueous and 95% methanol leaf extracts of four herbs viz. Trigonella foenum-graecum L, Murraya koenigii, Coriandrum sativum and Centella asiatica which have frequent use in Indian cuisine. Both aqueous and 95% methanol leaf extracts have shown significant amount reducing power. Both aqueous and 95% methanol leaf extracts of Coriandrum sativum had significant DPPH radical scavenging activity with IC50 value of 0.21± 0.3 mg/L and 0.176 ± 0.008 mg/L respectively. The aqueous leaf extract of Trigonella foenum-graecum L showed low scavenging activity. Among all the leaf extracts, the aqueous leaf extract of Centella asiatica has exhibited significantly high NO radical scavenging activity (80% with IC50 value of 0.11 ± 0.17 mg/L. The aqueous leaf extracts of the samples have showed significantly high superoxide radical scavenging activity. The activity was maximum for the aqueous leaf extract of Centella asiatica, IC50 value is 4.36 ± 0.41 mg/L. anti lipid peroxide activities were very high ( 90 % for aqueous leaf extracts of Coriandrum sativum (IC50 = 0.064 ± 0.85 mg/L and Centella asiatica (IC50 = 0.066 ± 0.9mg/L at a concentration of 0.16 mg/L. The aqueous leaf extracts of the samples were found to contain large amounts of flavonoids and phenolic compounds and exhibited high antioxidant and free radical scavenging activities. These in vitro assays indicate that these plant extracts are significant source of natural antioxidants which might be helpful in preventing the progress of various oxidative stresses.

  11. Are Trp53 rescue of Brca1 embryonic lethality and Trp53/Brca1 breast cancer association related?

    International Nuclear Information System (INIS)

    McAllister, Kimberly A; Wiseman, Roger W

    2002-01-01

    Brca1 is involved in multiple biological pathways including DNA damage repair, transcriptional regulation, and cell-cycle progression. A complex pattern of interactions of Brca1 with Trp53 has also emerged. Xu and coworkers found that haploid loss of Trp53 significantly reduces the embryonic lethality observed in mice with a homozygous in-frame deletion of Brca1 exon 11. They report that widespread apoptosis correlates with the embryonic lethality resulting from this homozygous Δ11 Brca1 mutation. A mechanism responsible for Brca1-associated carcinogenesis is proposed. These experiments extend our knowledge of a complex Brca1/Trp53 relationship. However, the precise mechanisms through which Brca1 interacts with Trp53 to suppress mammary tumor formation have yet to be elucidated

  12. Free radical scavenging activity and lipid peroxidation inhibition of Hypericum helianthemoides (spach Boiss

    Directory of Open Access Journals (Sweden)

    Soheila Moein

    2015-06-01

    Full Text Available Antioxidants are compounds that obstruct the oxidation of macromolecules in the body. In general, there are two categories of antioxidants, natural and synthetic. Recently, interest has been increased considerably for obtaining new natural antioxidants. In this study, the scavenging of free radicals such as DPPH, NO and OH by Hypericum helianthemoides extract was evaluated. Also, the antioxidant properties of this extract were evaluated by FRAP, FTC methods and determination phenolic compounds. The plant was collected from north of Fars Province and plant extraction was obtained using ethanol. In DPPH radical scavenging, different concentrations of the Hypericum extract were added to DPPH radical. In hydroxyl radical scavenging, Fenton reaction mixture, TCA and TBA were mixed with Hypericum extract. In nitric radical scavenging, nitropruside was mixed with Hypericum extract and then sulphanilic acid, naphthylene diamine were added. In determination of phenolic compounds, Folin-ciocalteu and sodium carbonate were added to Hypericum extract. In DPPH radical scavenging, the IC50 of Hypericum extract (309.35±6.5μg/ml was higher than the antioxidant standards, BHT (IC50=81.9±2.6 μg/ml and quercetin (IC50=60.04±6.48 μg/ml. The highest scavenging of hydroxyl radicals was observed in Hypericum extract (70.3±0.8%, 125 μg/ml. In gallic acid it was (73.8±3.3%. In 200 μg/ml of Hypericum extract scavenged NO radical (85.2±2.7%. In FRAP method, the IC50 of this extract was 109.7±10.5 μg/ml. In FTC method, the inhibition of lipid peroxidation by Hypericum extract, BHT and ascorbic acid were 59.2±2.2, 66.9±0.15, 64.06±0.02 respectively. Total phenol of the plant extract was 3±0.4 mg/g.

  13. Radical-Scavenging Activity of Thiols, Thiobarbituric Acid Derivatives and Phenolic Antioxidants Determined Using the Induction Period Method for Radical Polymerization of Methyl Methacrylate

    Directory of Open Access Journals (Sweden)

    Seiichiro Fujisawa

    2012-04-01

    Full Text Available The radical-scavenging activities of two thiols, eight (thiobarbituric acid derivatives and six chain-breaking phenolic antioxidants were investigated using the induction period method for polymerization of methyl methacrylate (MMA initiated by thermal decomposition of 2,2’-azobisisobutyronitrile (AIBN and monitored by differential scanning calorimetry (DSC. The induction period (IP for the thiols 2-mercaptoethanol (ME and 2-mercapto-1-methylimidazole (MMI was about half that for phenolic antioxidants. Except for the potent inhibitor 5,5-dimethyl-2-thiobarbituric acid (3, the IP for thiobarbituric acid derivatives was about one tenth of that for phenolic antioxidants. The IP for 1,3,5-trimethyl-2-thiobarbituric acid (1 and 5-allyl-1, 3-dimethyl-2-thiobarbituric acid (7 was less than that of the control, possibly due to inhibition by a small amount of atmospheric oxygen in the DSC container. The ratio of the chain inhibition to that of chain propagation (CI/CP for the thiols and thiobarbituric acid compounds except for 1, 3 and 7 was about 10 times greater or greater than that for phenolic compounds. A kinetic chain length (KCL about 10% greater than that of the control was observed for 1, suggesting that 1 had chain transfer reactivity in the polymerization of MMA. The average molecular weight of polymers formed from thiobarbituric acid derivatives is discussed.

  14. Depression of membrane-bound Na+-K+-ATPase activity induced by free radicals and by ischemia of kidney

    International Nuclear Information System (INIS)

    Kako, K.; Kato, M.; Matsuoka, T.; Mustapha, A.

    1988-01-01

    A partially purified, membrane-bound Na + -K + -ATPase fraction, prepared from the outer medulla of porcine kidney, was incubated in the presence of 0.1-100 mM H 2 O 2 for either 15 or 30 min at 37 degree C. The activity of ouabain-sensitive Na + -K + -ATPase was reduced proportionally to the concentration of H 2 O 2 and the duration of incubation. There were decreases in SH contents and turnover rates of the Na + -K + -ATPase preparation, while malondialdehyde (MDA) and conjugated dienes were generated from the membrane lipids in the course of the incubation. The concentrations of ethanolamine (E) plasmalogen and of arachidonic acid in the E glycerophospholipid molecules were reduced by the free radical reaction. Similarly, a reduction in Na + K + -ATPase activity and the formation of MDA and conjugated dienes, together with a decrease in E glycerophospholipids, were observed when the membrane fraction was exposed to ultraviolet irradiation (254 nm) for 30 min at 4 degree C. Microsomal fractions, prepared from the outer medulla of canine kidney after 1 h of unilateral ischemia and 1 h of reperfusion, showed a decreased Na + -K + -ATPase activity, a reduced amount of SH groups, and an increased MDA. These changes were normalized by the infusion of N-mercaptopropionylglycine. These results support the view (1) that free radical generation affects the enzyme protein as well as membrane lipids, and (2) that free radicals may be formed in the ischemic reperfused kidney

  15. New insights into the aquatic photochemistry of fluoroquinolone antibiotics: Direct photodegradation, hydroxyl-radical oxidation, and antibacterial activity changes.

    Science.gov (United States)

    Ge, Linke; Na, Guangshui; Zhang, Siyu; Li, Kai; Zhang, Peng; Ren, Honglei; Yao, Ziwei

    2015-09-15

    The ubiquity and photoreactivity of fluoroquinolone antibiotics (FQs) in surface waters urge new insights into their aqueous photochemical behavior. This study concerns the photochemistry of 6 FQs: ciprofloxacin, danofloxacin, levofloxacin, sarafloxacin, difloxacin and enrofloxacin. Methods were developed to calculate their solar direct photodegradation half-lives (td,E) and hydroxyl-radical oxidation half-lives (tOH,E) in sunlit surface waters. The td,E values range from 0.56 min to 28.8 min at 45° N latitude, whereas tOH,E ranges from 3.24h to 33.6h, suggesting that most FQs tend to undergo fast direct photolysis rather than hydroxyl-radical oxidation in surface waters. However, a case study for levofloxacin and sarafloxacin indicated that the hydroxyl-radical oxidation induced risky photochlorination and resulted in multi-degradation pathways, such as piperazinyl hydroxylation and clearage. Changes in the antibacterial activity of FQs caused by photodegradation in various waters were further examined using Escherichia coli, and it was found that the activity evolution depended on primary photodegradation pathways and products. Primary intermediates with intact FQ nuclei retained significant antibacterial activity. These results are important for assessing the fate and risk of FQs in surface waters. Copyright © 2015. Published by Elsevier B.V.

  16. Extracts and Constituents of Rubus chingii with 1,1-Diphenyl-2-picrylhydrazyl (DPPH Free Radical Scavenging Activity

    Directory of Open Access Journals (Sweden)

    Hsiou-Yu Ding

    2011-06-01

    Full Text Available The 1,1-diphenyl-2-picrylhydrazyl (DPPH free radical scavenging activity of the fruits of Rubus chingii was studied in vitro. Ethanolic extract, ethyl acetate and n-butanol fractions from dried R. chingii fruits revealed strong DPPH free radical scavenging activity with IC50 values of 17.9, 3.4 and 4.0 µg/mL, respectively. The ethyl acetate and n-butanol fractions were further purified by a combination of silica gel chromatography, Lobar RP-8 chromatography, and high-pressure liquid chromatography (HPLC. Nine compounds were isolated, where methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl-acetate (2, vanillic acid (5, kaempferol (7, and tiliroside (9 showed stronger DPPH free radical scavenging activity than that of ascorbic acid (131.8 µM with IC50 values of 45.2, 34.9, 78.5, and 13.7 µM, respectively. In addition, rubusine (1 is a new compound discovered in the present study and methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl-acetate (2, methyl dioxindole-3-acetate (3, and 2-oxo-1,2-dihydroquinoline-4-carboxylic acid (4 were isolated from the fruits for the first time.

  17. HPLC-Analysis of Polyphenolic Compounds in Gardenia jasminoides and Determination of Antioxidant Activity by Using Free Radical Scavenging Assays

    Directory of Open Access Journals (Sweden)

    Riaz Uddin

    2014-05-01

    Full Text Available Purpose: Gardenia jasminoides is a traditional medicinal plant rich in anti-inflammatory flavonoids and phenolic compounds and used for the treatment of inflammatory diseases and pain. In this present study, antioxidant potential of Gardenia jasminoides leaves extract was evaluated by using various antioxidant assays. Methods: Various antioxidant assays such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH radical scavenging assay, reducing power and total antioxidant capacity expressed as equivalent to ascorbic acid were employed. Moreover, phenolic compounds were detected by high-performance liquid chromatography (HPLC coupled with diode-array detection. Results: The methanol extract showed significant free radical scavenging activities in DPPH radical scavenging antioxidant assays compared to the reference antioxidant ascorbic acid. Total antioxidant activity was increased in a dose dependent manner. The extract also showed strong reducing power. The total phenolic content was determined as 190.97 mg/g of gallic acid equivalent. HPLC coupled with diode-array detection was used to identify and quantify the phenolic compounds in the extracts. Gallic acid, (+-catechin, rutin hydrate and quercetin have been identified in the plant extracts. Among the phenolic compounds, catechin and rutin hydrate are present predominantly in the extract. The accuracy and precision of the presented method were corroborated by low intra- and inter-day variations in quantitative results in leaves extract. Conclusion: These results suggest that phenolic compounds and flavonoids might contribute to high antioxidant activities of Gardenia jasminoides leaves.

  18. Effects of hydroxyl radical scavengers KCN and CO on ultraviolet light-induced activation of crude soluble guanylate cyclase

    International Nuclear Information System (INIS)

    Karlsson, J.O.; Axelsson, K.L.; Andersson, R.G.

    1985-01-01

    The crude soluble guanylate cyclase (GC) from bovine mesenteric artery was stimulated by ultraviolet (UV) light (366 nm). Addition of free radical scavengers, dimethylsulfoxide or superoxide dismutase and/or catalase to the GC assay did not abolish the stimulatory effect of UV light. On the contrary, the UV light-induced activation was enhanced in the presence of these scavengers. KCN (1 mM) did not affect the UV light-induced activation, while 0.1 mM of CO potentiated the activation. These results may indicate that UV light is operating through a direct interaction with the ferrous form of the GC-heme

  19. Changes of Major Antioxidant Compounds and Radical Scavenging Activity of Palm Oil and Rice Bran Oil during Deep-Frying

    Science.gov (United States)

    Abdul Hamid, Azizah; Pak Dek, Mohd Sabri; Tan, Chin Ping; Mohd Zainudin, Mohd Asraf; Wee Fang, Evelyn Koh

    2014-01-01

    Changes in antioxidant properties and degradation of bioactives in palm oil (PO) and rice bran oil (RBO) during deep-frying were investigated. The alpha (α)-tocopherol, gamma (γ)-tocotrienol and γ-oryzanol contents of the deep-fried oils were monitored using high performance liquid chromatography, and antioxidant activity was determined using 2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity. Results revealed that the antioxidant activity of PO decreased significantly (p -oryzanol and γ-tocotrienol in RBO may have a protective effect on α-tocopherol during deep-frying. PMID:26785067

  20. [The significance of free radicals and antioxidants due to the load induced by sport activity].

    Science.gov (United States)

    Holecek, V; Liska, J; Racek, J; Rokyta, R

    2004-01-01

    Sport performance is followed by a high production of free radicals. The main reasons are reperfusion after the previous imbalance between the increased need of the organism and the ability of blood supply by oxygen, increased production of ATP, decomposition of the cells particularly white blood cells, oxidation of the purin basis from DNA, stress, output of epinephrine release of free iron, increased temperature in the muscle and its inflammation, and the reception of free radicals from external environment. Peroxidation of lipids, proteins, DNA and other compounds follows the previous biochemical steps. Antioxidants are consumed by free radicals, antioxidative enzymes are released into blood plasma, intracellular calcium is increased, the production of nitric oxide rises, the levels of hydrogen peroxide and hypochlorous acid increase. These penetrate through the membranes and oxidatively damage the tissues. Training improves the ability of the organism to balance the increased load of free radicals. The damage can be lowered by the application of a mixture of antioxidants, the most important are vitamin C, A, E, glutathione, selenium, carnosine, eventually bioflavonoids and ginkgo biloba. The lack of antioxidants can significantly diminish the sport performance and therefore the supplementation with antioxidants is for top sportsmen but also for aged people advisable.

  1. Inhibition of Procarcinogen Activating Enzyme CYP1A2 Activity and Free Radical Formation by Caffeic Acid and its Amide Analogues.

    Science.gov (United States)

    Narongchai, Paitoon; Niwatananun, Kanokporn; Narongchai, Siripun; Kusirisin, Winthana; Jaikang, Churdsak

    2016-01-01

    Caffeic acid (CAF) and its amide analogues, ethyl 1-(3',4'-dihydroxyphenyl) propen amide (EDPA), phenethyl 1-(3',4'-dihydroxyphenyl) propen amide (PEDPA), phenmethyl 1- (3',4'-dihydroxyphenyl) propen amide (PMDPA) and octyl 1-(3',4'-dihydroxyphenyl) propen amide (ODPA) were investigated for the inhibition of procarcinogen activating enzyme. CYP1A2 and scavenging activity on formation of nitric oxide, superoxide anion, DPPH radical and hydroxyl radical. It was found that they inhibited CYP1A2 enzyme by uncompetitive inhibition. Apparent Ki values of CAF, EDPA, PEDPA, PMDPA and ODPA were 0.59, 0.39, 0.45, 0.75 and 0.80 µM, respectively suggesting potent inhibitors of CYP1A2. Moreover, they potentially scavenged nitric oxide radical with IC 50 values of 0.12, 0.22, 0.28, 0.22 and 0.51 mM, respectively. The IC50 values of superoxide anion scavenging were 0.20, 0.22, 0.44, 2.18 and 2.50 mM, respectively. 1, 1- diphenyl-2- picrylhydrazyl (DPPH) radical-scavenging ability, shown as IC50 values, were 0.41, 0.29, 0.30, 0.89 and 0.84 mM, respectively. Moreover, the hydroxyl radical scavenging in vitro model was shown as IC50 values of 23.22, 21.06, 17.10, 17.21 and 15.81 µM, respectively. From our results, caffeic acid and its amide analogues are in vitro inhibitors of human CYP1A2 catalytic activity and free radical formation. They may be useful to be developed as potential chemopreventive agents that block CYP1A2-mediated chemical carcinogenesis.

  2. In vitro alpha glucosidase inhibition and free-radical scavenging activity of propolis from Thai stingless bees in mangosteen orchard

    Directory of Open Access Journals (Sweden)

    Boonyadist Vongsak

    Full Text Available ABSTRACTThe chemical component and biological activity of propolis depend on flora area of bee collection and bee species. In the study, the propolis from three stingless bee species, Lepidotrigona ventralis Smith, Lepidotrigona terminata Smith, and Tetragonula pagdeni Schwarz, was collected in the same region of mangosteen garden from Thailand. Total phenolic content, alpha glucosidase inhibitory effect, and free-radical scavenging activity using FRAP, ABTS, DPPH assays were determined. The most potent activity of propolis extract was investigated for bioactive compounds and their quantity. The ethanol extract of T. pagdeni propolis had the highest total phenolic content 12.83 ± 0.72 g of gallic acid equivalents in 100 g of the extract, and the strongest alpha glucosidase inhibitory effect with the IC50 of 70.79 ± 6.44 µg/ml. The free-radical scavenging activity evaluated by FRAP, ABTS, DPPH assays showed the FRAP value of 279.70 ± 20.55 µmol FeSO4 equivalent/g extract and the IC50 of 59.52 ± 10.76 and 122.71 ± 11.76 µg/ml, respectively. Gamma- and alpha-mangostin from T. pagdeni propolis extract were isolated and determined for the biological activity. Gamma-mangostin exhibited the strongest activity for both alpha glucosidase inhibitory effect and free-radical scavenging activity. Using HPLC quantitative analysis method, the content of gamma- and alpha-mangostin in the extract was found to be 0.94 ± 0.01 and 2.77 ± 0.08% (w/w, respectively. These findings suggested that T. pagdeni propolis may be used as a more suitable raw material for nutraceutical and pharmaceutical products and these mangostin derivatives as markers.

  3. Synthesis of Amino Acid Analogues of 5H-Dibenz[b,f]azepine and Evaluation of their Radical Scavenging Activity

    Directory of Open Access Journals (Sweden)

    H. Vijay Kumar

    2009-01-01

    Full Text Available A method for the synthesis of tyrosine, phenyl alanine, hydroxy proline and threonine free amino acid analogues of 5H-dibenz[b,f]azepine is proposed. 5H-dibenz[b,f]azepine was prepared by known method. The key intermediate 3-chloro-1-(5H-dibenz[b,f]azepine-5-ylpropan-1-one was obtained by N-acylation of 5H-dibenz[b,f]azepine with 3-chloro propionyl chloride. Further coupling of respective free amino acid to produce 2-(3-(5H-dibenz[b,f]azepine-5-yl-3-oxopropylamino3-(4 hydroxyphenyl propanoic acid, 2-(3-(5H-dibenz[b,f]azepine-5-yl-3-oxopropylamino-3-phenyl propanoicacid,1-(3-(5H-dibenz[b,f]azepine-5-yl-3-oxopropyl-3-hydroxypyrolidine-2-carboxylic acid and 2-(3-(5H-dibenz[b,f] azepine-yl-3-oxopropyl amino-3-hydroxy butanoic acid. The synthesized compounds were evaluated for their potential over 1,1-diphenyl-2-picryl hydrazyl (DPPH free radical scavenging activity. Butylated hydroxy anisole (BHA and ascorbic acid (AA were used as the reference antioxidant compounds and also the comparative study with synthesized compounds was done. Under our experimental conditions tyrosine, hydroxy proline and threonine analogues possess a direct scavenging effect on trapping the stable free radical DPPH. Hydroxy proline analogues showed a significant radical scavenging activity among the synthesized analogues

  4. Definitive pathology at radical prostatectomy is commonly favorable in men following initial active surveillance.

    Science.gov (United States)

    Hong, Sung Kyu; Sternberg, Itay A; Keren Paz, Gal E; Kim, Philip H; Touijer, Karim A; Scardino, Peter T; Eastham, James A

    2014-08-01

    Limited data are currently available regarding the outcomes of radical prostatectomy (RP) in men with low-risk prostate cancer who were initially managed by active surveillance (AS). To evaluate the pathologic outcomes of patients who underwent RP following initial AS. We analyzed the records of 67 patients who underwent RP following initial AS begun between 1993 and 2011. All patients underwent confirmatory biopsy to reassess eligibility for AS. RP was recommended for disease progression suggested by follow-up biopsies or imaging. Unfavorable disease was defined as having at least one of the following pathologic findings: Gleason score (GS) ≥4+3, extracapsular extension of tumor, seminal vesicle invasion, or lymph node involvement. A descriptive analysis was performed to assess pathologic features. Median time from confirmatory biopsy to RP was 1.7 yr (range: 0.3-7.8). Reasons for discontinuing AS to undergo RP included evidence of increased tumor volume or grade on follow-up biopsy, patient preference/anxiety, and findings on follow-up imaging in 46 patients (68.7%), 17 patients (25.3%), and 4 patients (6.0%), respectively. Pathologic analyses revealed organ-confined disease in 55 patients (82.1%), and GS was ≥4+3 in 9 (13.4%). Positive nodes were observed in three patients (4.4%) and positive surgical margin in two (3.0%). Overall, 19 patients (28.4%) had unfavorable disease. Of the biopsy criteria for triggering RP, Gleason patterns >3 were the most frequently associated with unfavorable disease (43.3%). One patient (1.5%) experienced biochemical recurrence during postoperative follow-up (median: 3.2 yr). Our study may be limited by its retrospective and single-institution nature. Most patients who started initially on AS after undergoing confirmatory biopsy showed pathologically organ-confined disease with a low GS at RP. Such findings provide further evidence that, overall, AS is a safe treatment approach. Copyright © 2013. Published by Elsevier B.V.

  5. Can primary reducing radicals be recruited for prodrug activation in tissue?

    International Nuclear Information System (INIS)

    Kriste, A.G.; Ferry, D.M.; Anderson, R.F.; Wilson, W.R.

    2003-01-01

    We have previously demonstrated that the nitroarylmethyl quaternary ammonium (NMQ) prodrugs of mechlorethamine (HN2) can be activated under anoxia by ionizing radiation (Kriste et al. Radiation Research, 158, 753 - 762, 2002). The HN2 released by these model compounds, however, is insufficiently potent for the prodrugs to be therapeutically useful. To address this concern, NMQ trigger units (4-nitroimidazole, 2-nitropyrrole and 3-nitrothiophene; all demonstrate one-electron release of HN2) were tethered to the DNA intercalator, AMAC (IC 50 values of 1.3 to 66 nM against human and rodent tumour cells). We now report whether AMAC can be radiolytically released from NMQ-AMAC prodrugs in a hypoxic tissue-like environment. Initially radiolysis was investigated in anoxic 0.1 M Formate buffer. Here, the G value for AMAC release was 0.33 ± 0.02μmol/J. In anoxic human plasma, radiolytic release was half as efficient (G(AMAC)= 0.18 ± 0.03μmol/J). To investigate AMAC release in tissue, V79-171b rodent tumour cells were seeded onto Millicell-CM cell culture inserts and grown to 10 - 20 cell diameters. These multicellular layers (MCLs) were equilibrated with prodrug (1μM, 4 hours), and transferred to a gassing chamber (95% nitrogen or oxygen, 2 minutes). MCLs were irradiated (high dose linear accelerator, 0 - 800 Gy, 35 Gy/pulse) and lysed. HPLC analysis indicated that each prodrug was taken up intracellularly to ca. 50 μM. Furthermore, AMAC release was linear with radiation dose and was inhibited under oxia. In this tissue, G values spanned a range from 9.0 to 15 nmol/J. These low values, ca. 5 % of the plasma value, are interpreted as reflecting unfavourable prodrug localization into acidic intracellular endosomes, with no clear E(1) dependance. Whether radiolytic reduction occurs via e aq - or H . abstraction to generate carbon-centred radicals is unknown. MCL studies with NMQ prodrugs that release alternate amine containing cytotoxins are currently in progress

  6. Antinociceptive and free radical scavenging activities of Cocos nucifera L. (Palmae) husk fiber aqueous extract.

    Science.gov (United States)

    Alviano, Daniela S; Rodrigues, Karen F; Leitão, Suzana G; Rodrigues, Marcio L; Matheus, Maria Eline; Fernandes, Patrícia D; Antoniolli, Angelo R; Alviano, Celuta S

    2004-06-01

    In the current study, the analgesic and free radical scavenging properties of an aqueous extract from the husk fiber of Cocos nucifera L. (Palmae) were demonstrated by the use of in vivo and in vitro models. The orally administered Cocos nucifera aqueous extract (200 or 400 mg/kg) inhibited the acetic acid-induced writhing response in mice. Tail flick and hot plate assays demonstrated that treatment of animals with this plant extract at 200 mg/kg induced attenuation in the response to a heat stimulus. A LD(50) of 2.30 g/kg was obtained in acute toxicity tests. Topic treatment of rabbits with the Cocos nucifera extract indicated that it does not induce any significant dermic or ocular irritation. In vitro experiments using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) photometric assay demonstrated that this plant extract also possesses free radical scavenging properties.

  7. Enhancement of carboxylic acid degradation with sulfate radical generated by persulfate activation.

    Science.gov (United States)

    Criquet, J; Nebout, P; Karpel Vel Leitner, N

    2010-01-01

    The aim of this work was to investigate the generation of sulfate radical for the removal of two carboxylic acids in aqueous solution: acetic and citric acids. From photochemical and radiolytic processes, kinetics of the degradation of these two carboxylic acids was studied as a function of the pH of the solution. It was shown that the maximum of acetic acid degradation occurred at pH 5. Above this pH, competitive reactions with the carbon mineralized inhibit the reaction of with the solute. In the case of citric acid, pH has only a little effect on the kinetic of citric acid degradation. The determination of mineralization yields shows several differences depending on carboxylic acids and pH. The degradation of both carboxylic acids was also studied in the radiolysis process whether with or without persulfate addition. A comparison of the processes of sulfate radical production is presented.

  8. Quantum chemical modeling of antioxidant activity of glutathione interacting with hydroxyl- and superoxide anion radicals

    Directory of Open Access Journals (Sweden)

    N. V. Solovyova

    2015-04-01

    Full Text Available Following the analysis of the results of quantum chemical simulation of interaction between a GSH molecule and oxygen radicals •ОН and •ООˉ, it was found that it takes place through the acid-base mechanism, where GSH acts as a base towards •ОН, and as an acid towards •ООˉ. The results of quantum chemical calculations (electron density redistribution, energy characteristics were correlated at the time of interaction of a GSH molecule with •ОН and •ООˉ with a change of macroscopic parameters of the process of free oxygen radical electroreduction in the presence of GSH (potential and maximum current of reduction waves, which is a direct experimental macroscale evidence of results of the conducted nanoscale theoretical simulation.

  9. Radical scavenging potential, antiinflammatory and antiarthritic activity of isolated isomer Methyl-γ-Orsellinate and roccellatol from Roccella montagnei Bel

    Directory of Open Access Journals (Sweden)

    Syed Zameer Ahmed Khader

    2018-06-01

    Full Text Available The burden of multiple drug resistance towards chronic diseases is rapidly increasing globally at an alarm rate. The present study aims to isolate active principles via bioassay guided fractionation of traditionally used lichen Roccella montagnei for in vitro radical scavenging activity with potential to combat arthritis and inflammation. The results of proximate composition and mineral analysis revealed the presence of essential amount of micro and macro nutrients which are required for secondary metabolite production. Fractions of Roccella montagnei and pure compounds were assessed for its in vitro antioxidant (DPPH, FRAP, OH radical, SOD, CAT, GPX, antiarthritic and antiinflammatory activity. The results indicates that lichen sample and fractions exhibited potent radical scavenger demonstrated in vitro antiarthritic and antiinflammatory activity in dose dependent manner. Bioassay fractionation lead to isolation of two pure compounds ie., Compound I and Compound II which were characterized using spectral data such as FT-IR, 1H NMR, 13C NMR, DEPT NMR spectroscopy, COSY & HMQC NMR spectroscopy and LC-MS analysis and was identified as Methyl-γ-Orsellinate (C9H10O4 a novel isomer from fractions E2d5a with a molecular weight of 182.2 and Roccellatol (C12H16O7 from fractions D3d4c with a molecular weight of 272.3. The present findings suggest that the secondary metabolites present in the lichens have direct relation, with biological activities revealing different properties and can be a future novel antioxidant and a potent anti-arthritic agent.

  10. Functional Teas from the Leaves of Arbutus unedo: Phenolic Content, Antioxidant Activity, and Detection of Efficient Radical Scavengers.

    Science.gov (United States)

    Erkekoglou, Ioannis; Nenadis, Nikolaos; Samara, Efrosini; Mantzouridou, Fani Th

    2017-06-01

    The phenolic content/composition and antioxidant activity of hot/cold infusion and decoction from the leaves of Arbutus unedo were studied for the first time. 1,1-diphenyl-2-picrylhydrazyl (DPPH ● ), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS ●+ ), crocin-bleaching, copper-reducing, and liposome accelerated oxidation assays were used for the evaluation of the activity in vitro. In vivo, the extracts were examined for their ability to protect S. cerevisiae cells from H 2 O 2 induced oxidative stress. An on-line high-performance liquid chromatography-DPPH ● assay was applied to identify potent radical scavengers and comment on their contribution to the total activity. The addition of leaves to boiling water (decoction) was the most appropriate practice to apply since the highest phenol intake (220.2 mg gallic acid/cup served) was obtained. Additionally, its antioxidant activity was equal or superior to that of the other extracts. Flavonols (~51-61 mg/g dry extract) were the main phenols in all the extracts, with quercitrin accounting for ~20% of the total phenol amount. The on-line DPPH ● method verified the high potency of the decoction and indicated as the most active radical scavengers, two galloylquinic acid derivatives and myricitrin, accounting for ~28-45% and ~11-13% of the total scavenging, respectively. Present data may contribute to the future exploitation of A. unedo leaves by the food industry for health-promoting herbal tea preparations and dietary supplements.

  11. Free radical scavenging activity and secondary metabolites from in vitro cultures of Sanicula graveolens.

    Science.gov (United States)

    Cheel, José; Schmeda-Hirschmann, Guillermo; Jordan, Miguel; Theoduloz, Cristina; Rodríguez, Jaime A; Gerth, André; Wilken, Dirk

    2007-01-01

    An in vitro propagation system was developed to obtain shoot and root cultures from the Andean spice Sanicula graveolens (Apiaceae). Propagation of shoots, roots and plantlets was achieved by the temporary immersion system. The free radical scavenging effect of the methanol/water (7:3 v/v) extracts was determined by the discoloration of the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH). Total phenolic, flavonoid, chlorogenic acid (CA) and quercetin 3-O-glucoside content in the samples was assessed by spectrophotometry and DAD-HPLC analysis, respectively. On a dry weight basis, the crude extracts showed total phenolic values ranging from 3.57 to 6.93%, with highest content for the root culture sample. Total flavonoid content ranged from 1.23 to 2.23% and was lower for the root culture. Chlorogenic acid and neochlorogenic acid were identified by TLC in all samples. Highest free radical scavenging effect was observed for the root culture which also presented the highest CA content. Two of the shoot culture samples, with similar IC50 values in the DPPH discoloration assay, also presented close quercetin-3-O-glucoside content.

  12. Evidence of free radical and antioxidant activity in Spirodela exposed to metallic and metal oxide nanoparticles: potential for protein and lipid damage

    CSIR Research Space (South Africa)

    Thwala, Melusi

    2012-04-01

    Full Text Available the quantities of free radicals (H202, total ROS/RNS), antioxidant activity (catalase, superoxide disrnutasc, and total antioxidam capacity) were analyzed. Oxidative stress has been suggested as a significant route of toxicity induction by engineered...

  13. The scavenging of free radical and oxygen species activities and hydration capacity of collagen hydrolysates from walleye pollock ( Theragra chalcogramma) skin

    Science.gov (United States)

    Zhuang, Yongliang; Li, Bafang; Zhao, Xue

    2009-06-01

    Fish skin collagen hydrolysates (FSCH) were prepared from walleye pollock ( Theragra chalcogramma) using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of <1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical (DPPH), superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione (GSH). FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore, FSCH may have potential applications in the medicine and food industries.

  14. Chemical Composition, In Vitro Antimicrobial, Free-Radical-Scavenging and Antioxidant Activities of the Essential Oil of Leucas inflata Benth

    Directory of Open Access Journals (Sweden)

    Ramzi A. Mothana

    2017-02-01

    Full Text Available The essential oil of Leucas inflata Balf.f. (Lamiaceae, collected in Yemen, was analyzed using gas chromatography (GC and gas chromatography-mass spectrometry (GC-MS techniques. Forty-three components were recognized, representing 89.2% of the total oil. The L. inflata volatile oil was found to contain a high percentage of aliphatic acids (51.1%. Hexadecanoic acid (32.8% and n-dodecanoic acid (7.8% were identified as the major compounds. Oxygenated monoterpenes were distinguished as the second significant group of constituents (16.0%. Camphor (6.1% and linalool (3.2% were found to be the main components among the oxygenated monoterpenes. In addition, the volatile oil was assessed for its antimicrobial activity against four bacterial strains and one yeast species using broth micro-dilution assay for minimum inhibitory concentrations (MIC. In addition, antioxidant activity was measured utilizing the anti-radical activity of the sable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH and β-Carotene-linoleic acid assays. The oil of L. inflata showed an excellent antibacterial activity against only the tested Gram-positive bacteria with a MIC-value of 0.81 mg/mL. Furthermore, the oil demonstrated, at a concentration of 1 mg/mL, a weak to moderate antiradical and antioxidant activity of 38% and 32%, respectively.

  15. Development of Chemically Defined Media to Express Trp-Analog-Labeled Proteins in a Lactococcus lactis Trp Auxotroph.

    Science.gov (United States)

    Shao, Jinfeng; Marcondes, Marcelo F M; Oliveira, Vitor; Broos, Jaap

    2016-01-01

    Chemically defined media for growth of Lactococcus lactis strains contain about 50 components, making them laborious and expensive growth media. However, they are crucial for metabolism studies as well as for expression of heterologous proteins labeled with unnatural amino acids. In particular, the L. lactis Trp auxotroph PA1002, overexpressing the tryptophanyl tRNA synthetase enzyme of L. lactis, is very suitable for the biosynthetic incorporation of Trp analogs in proteins because of its most relaxed substrate specificity reported towards Trp analogs. Here we present two much simpler defined media for L. lactis, which consist of only 24 or 31 components, respectively, and with which the L. lactis Trp auxotroph shows similar growth characteristics as with a 50-component chemically defined medium. Importantly, the expression levels of two recombinant proteins used for evaluation were up to 2-3 times higher in these new media than in the 50-component medium, without affecting the Trp analog incorporation efficiency. Taken together, the simplest chemically defined media reported so far for L. lactis are presented. Since L. lactis also shows auxotrophy for Arg, His, Ile, Leu Val, and Met, our simplified media may also be useful for the biosynthetic incorporation of analogs of these five amino acids. © 2016 The Author(s) Published by S. Karger AG, Basel.

  16. Physiology of free radicals

    Directory of Open Access Journals (Sweden)

    Stevanović Jelka

    2011-01-01

    Full Text Available Free radicals imply that every atom, molecule, ion, group of atoms, or molecules with one or several non-paired electrons in outer orbital. Among these are: nitrogenoxide (NO•, superoxide-anion-radical (O2•-, hydroxyl radical (OH•, peroxyl radical (ROO•, alcoxyl radical (RO• and hydroperoxyl radical (HO2•. However, reactive oxygen species also include components without non-paired electrons in outer orbital (so-called reactive non-radical agents, such as: singlet oxygen (1O2, peroxynitrite (ONOO-, hydrogen-peroxide (H2O2, hypochloric acid (eg. HOCl and ozone (O3. High concentrations of free radicals lead to the development of oxidative stress which is a precondition for numerous pathological effects. However, low and moderate concentrations of these matter, which occur quite normally during cell metabolic activity, play multiple significant roles in many reactions. Some of these are: regulation of signal pathways within the cell and between cells, the role of chemoattractors and leukocyte activators, the role in phagocytosis, participation in maintaining, changes in the position and shape of the cell, assisting the cell during adaption and recovery from damage (e.g.caused by physical effort, the role in normal cell growth, programmed cell death (apoptosis and cell ageing, in the synthesis of essential biological compounds and energy production, as well as the contribution to the regulation of the vascular tone, actually, tissue vascularization.

  17. TrpC5 Mediates Acute Leptin and Serotonin Effects via Pomc Neurons

    Directory of Open Access Journals (Sweden)

    Yong Gao

    2017-01-01

    Full Text Available The molecular mechanisms underlying acute leptin and serotonin 2C receptor-induced hypophagia remain unclear. Here, we show that neuronal and pro-opiomelanocortin (Pomc-specific loss of transient receptor potential cation 5 (TrpC5 subunits is sufficient to decrease energy expenditure and increase food intake resulting in elevated body weight. Deficiency of Trpc5 subunits in Pomc neurons is also sufficient to block the anorexigenic effects of leptin and serotonin 2C receptor (Ht2Cr agonists. The loss of acute anorexigenic effects of these receptors is concomitant with a blunted electrophysiological response to both leptin and Ht2Cr agonists in arcuate Pomc neurons. We also demonstrate that the Ht2Cr agonist lorcaserin-induced improvements in glucose and insulin tolerance are blocked by TrpC5 deficiency in Pomc neurons. Together, our results link TrpC5 subunits in the brain with leptin- and serotonin 2C receptor-dependent changes in neuronal activity, as well as energy balance, feeding behavior, and glucose metabolism.

  18. Microbial inhibitory and radical scavenging activities of cold-pressed terpeneless Valencia orange (Citrus sinensis) oil in different dispersing agents.

    Science.gov (United States)

    Chalova, Vesela I; Crandall, Philip G; Ricke, Steven C

    2010-04-15

    Due to their low solubility in water, oil-based bioactive compounds require dispersion in a surface-active agent or appropriate solvents to ensure maximum contact with microorganisms. These combinations, however, may change their physical and/or chemical characteristics and consequently alter the desired functionality. The objective of this study was to determine the impact of selected dispersing agents, ethanol, dimethyl sulfoxide (DMSO), and Tween-80, on cold-pressed terpeneless (CPT) Valencia orange oil to function as a free radical scavenger and an antimicrobial food additive. When dissolved in ethanol or DMSO, the orange oil fraction had similar minimum inhibitory concentrations (MIC) for Listeria monocytogenes ATCC 19 115 (0.3% and 0.25% v/v respectively), which were significantly lower (P orange oil (up to 3%) in an aqueous solution of 0.1% Tween-80 yielded no inhibitory activities against any of the test bacteria. However, the 1% natural orange oil dispersed in Tween-80 exhibited 56.86% 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical inhibition versus 18.37% and 16.60% when the same level of orange oil was dissolved in DMSO or ethanol, respectively. At the same orange oil concentration, the oil/Tween-80 suspension yielded 57.92% neutralization of hydroxyl radicals. This represents 71.37% of the mannitol antioxidant activity, which was used as a positive control. These findings suggest that Tween-80 is an appropriate dispersing agent only if the antioxidant functionality is desired. If both antimicrobial and antioxidant properties are needed, the CPT Valencia orange oil should be dispersed in either DMSO or ethanol. (c) 2010 Society of Chemical Industry.

  19. Depression of membrane-bound Na sup + -K sup + -ATPase activity induced by free radicals and by ischemia of kidney

    Energy Technology Data Exchange (ETDEWEB)

    Kako, K.; Kato, M.; Matsuoka, T.; Mustapha, A. (Univ. of Ottawa, Ontario (Canada))

    1988-02-01

    A partially purified, membrane-bound Na{sup +}-K{sup +}-ATPase fraction, prepared from the outer medulla of porcine kidney, was incubated in the presence of 0.1-100 mM H{sub 2}O{sub 2} for either 15 or 30 min at 37{degree}C. The activity of ouabain-sensitive Na{sup +}-K{sup +}-ATPase was reduced proportionally to the concentration of H{sub 2}O{sub 2} and the duration of incubation. There were decreases in SH contents and turnover rates of the Na{sup +}-K{sup +}-ATPase preparation, while malondialdehyde (MDA) and conjugated dienes were generated from the membrane lipids in the course of the incubation. The concentrations of ethanolamine (E) plasmalogen and of arachidonic acid in the E glycerophospholipid molecules were reduced by the free radical reaction. Similarly, a reduction in Na{sup +}K{sup +}-ATPase activity and the formation of MDA and conjugated dienes, together with a decrease in E glycerophospholipids, were observed when the membrane fraction was exposed to ultraviolet irradiation (254 nm) for 30 min at 4{degree}C. Microsomal fractions, prepared from the outer medulla of canine kidney after 1 h of unilateral ischemia and 1 h of reperfusion, showed a decreased Na{sup +}-K{sup +}-ATPase activity, a reduced amount of SH groups, and an increased MDA. These changes were normalized by the infusion of N-mercaptopropionylglycine. These results support the view (1) that free radical generation affects the enzyme protein as well as membrane lipids, and (2) that free radicals may be formed in the ischemic reperfused kidney.

  20. The elevation effect on water-soluble polysaccharides and DPPH free radical scavenging activity of Ganoderma lucidum K

    Science.gov (United States)

    Darsih, C.; Apriyana, W.; Nur Hayati, S.; Taufika Rosyida, V.; Hernawan; Dewi Poeloengasih, C.

    2017-02-01

    Water soluble polysaccharide is one of the important phytochemical in Ganoderma lucidum K. Phytochemicals in the plants, microorganisms, and plants were affected by internal and external factors. The objective of the research was to evaluate the effect of elevation on the water-soluble polysaccharides and its DPPH radical scavenging activity. We found that the water-polysaccharides in mushroom from Godean (elevation Ganoderma lucidum K from Godean (IC50 11.5 ± 0.29 mg/mL) higher than Kaliurang (IC50 14.4 ± 0.27%).

  1. The Cytotoxic, Antibacterial and Free Radical Scavenging Activities of Crude Extracts of Matricaria chamomilla, Salvadora persica and Artemisia annua

    KAUST Repository

    Seddek, Ahmed

    2011-12-01

    The discovery of drugs from natural sources has been a rapidly growing science in this era. Plants used for medicinal purposes have been usually studied as rich sources of bioactive chemical compounds that can be used as medications. Several plant-derived drugs have been approved so far. Cancer and infectious diseases have been common targets for the science of drug discovery, due to the high mortality rates caused by these diseases all over the world. Several plant-derived compounds are being marketed now as anti-cancer agents. However, finding novel antimicrobial and anti-cancer compounds has become an important goal to overcome the problems of existing anti-cancer and antimicrobial agents, such as resistance and non-selectivity. In this thesis project, an attempt to find out useful biological activities of the crude extracts of some plants used traditionally for medicinal purposes in Saudi Arabia has been made. Matricaria chamomilla, Salvadora persica and Artemisia annua have been selected for study, based on the literature review performed. These plants were screened for three biological activities; anti-cancer, anti-bacterial and free radical scavenging activities. The experimental part of the study consisted of some common in-vitro techniques, such as cytotoxicity and cell viability assays, disk diffusion assay and 1,1-diphenyl-2-picryl-hydrazyl assay. In addition, the crude extract of Matricaria chamomilla has undergone chemical fractionation and four solvent fractions were obtained using column chromatography. The crude extract of Matricaria chamomilla showed a promising anti-bacterial activity against Escherichia coli and a very promising free radical scavenging activity that was comparable to ascorbic acid, an important anti-oxidant. The four solvent fractions obtained from that extract showed that these activities were produced by more than one compound belonging to different solvent fractions. In addition, the crude extract of Artemisia annua showed

  2. A study on the comparison of antioxidant effects among cultivated ginseng, and cultivated wild ginseng extracts -Using the measurement of superoxide and hydroxy radical scavenging activities-

    Directory of Open Access Journals (Sweden)

    Tae Jin, Rhim

    2009-06-01

    Full Text Available Objectives : The objective of this study was to compare the antioxidant effects among cultivated wild ginseng and ginseng extracts. Methods : In vitro antioxidant activities were examined by superoxide and hydroxyl radical scavenging activities of ginseng and cultivated wild ginseng extracts. Results : 1. In the superoxide radical scavenging activities of ginseng and cultivated wild ginseng extracts, antioxidant activities of cultivated wild ginseng extracts was showed higher than cultivated ginseng in the concentration of 0.25 and 0.50㎎/㎖. 2. In the hydroxyl radical scavenging activities of ginseng and cultivated wild ginseng extracts, antioxidant activities of cultivated wild ginseng extracts was showed higher than cultivated ginseng in the concentration of 1.0, 2.5, and 5.0㎎/㎖. Conclusions : In summary, the results of this study demonstrate that cultivated wild ginseng extracts had higher antioxidant activities to cultivated ginseng.

  3. Loss of Cdh1 and Trp53 in the uterus induces chronic inflammation with modification of tumor microenvironment.

    Science.gov (United States)

    Stodden, G R; Lindberg, M E; King, M L; Paquet, M; MacLean, J A; Mann, J L; DeMayo, F J; Lydon, J P; Hayashi, K

    2015-05-07

    Type II endometrial carcinomas (ECs) are estrogen independent, poorly differentiated tumors that behave in an aggressive manner. As TP53 mutation and CDH1 inactivation occur in 80% of human endometrial type II carcinomas, we hypothesized that mouse uteri lacking both Trp53 and Cdh1 would exhibit a phenotype indicative of neoplastic transformation. Mice with conditional ablation of Cdh1 and Trp53 (Cdh1(d/d)Trp53(d/d)) clearly demonstrate architectural features characteristic of type II ECs, including focal areas of papillary differentiation, protruding cytoplasm into the lumen (hobnailing) and severe nuclear atypia at 6 months of age. Further, Cdh1(d/d)Trp53(d/d) tumors in 12-month-old mice were highly aggressive, and metastasized to nearby and distant organs within the peritoneal cavity, such as abdominal lymph nodes, mesentery and peri-intestinal adipose tissues, demonstrating that tumorigenesis in this model proceeds through the universally recognized morphological intermediates associated with type II endometrial neoplasia. We also observed abundant cell proliferation and complex angiogenesis in the uteri of Cdh1(d/d)Trp53(d/d) mice. Our microarray analysis found that most of the genes differentially regulated in the uteri of Cdh1(d/d)Trp53(d/d) mice were involved in inflammatory responses. CD163 and Arg1, markers for tumor-associated macrophages, were also detected and increased in the uteri of Cdh1(d/d)Trp53(d/d) mice, suggesting that an inflammatory tumor microenvironment with immune cell recruitment is augmenting tumor development in Cdh1(d/d)Trp53(d/d) uteri. Further, inflammatory mediators secreted from CDH1-negative, TP53 mutant endometrial cancer cells induced normal macrophages to express inflammatory-related genes through activation of nuclear factor-κB signaling. These results indicate that absence of CDH1 and TP53 in endometrial cells initiates chronic inflammation, promotes tumor microenvironment development following the recruitment of macrophages

  4. Phenolic profile and free radical-scavenging activity of Cabernet Sauvignon wines of different geographical origins from the Balkan region.

    Science.gov (United States)

    Radovanović, Blaga C; Radovanović, Aleksandra N; Souquet, Jean-Marc

    2010-11-01

    The phenolic profile, determined by the relative proportions of different phenolic compounds, is characteristic for each grape variety and its corresponding wine. The aim of this study was to determine the phenolic and hydroxycinnamate acid, flavan-3-ol and flavonol contents and free radical-scavenging activity of single-cultivar (Cabernet Sauvignon) wines from selected Balkan vineyard regions by spectrophotometric methods and high-performance liquid chromatography with photodiode array and fluorescence detection. The contents of phenolic compounds varied depending on the agroclimatic factors and oenological practices of the vineyard region. The antioxidant activity of wine samples was estimated by their ability to scavenge the stable 2,2'-diphenyl-1-picrylhydrazyl free radical (DPPH). All wines showed high DPPH-scavenging activity (70.03-83.53%, mean 73.76%). Significant correlations between catechin (R(2) = 0.8504) and quercetin (R(2) = 0.8488) concentrations and DPPH-scavenging ability of the wines were found. The concentrations of the main components catechin and quercetin can be used as biochemical markers for the authentication of red grape cultivars and their corresponding single-cultivar wines. 2010 Society of Chemical Industry

  5. Isolation, chemical characterization, and free radical scavenging activity of phenolics from Triticum aestivum L. aerial parts.

    Science.gov (United States)

    Kowalska, Iwona; Pecio, Lukasz; Ciesla, Lukasz; Oleszek, Wieslaw; Stochmal, Anna

    2014-11-19

    Fourteen phenolic compounds (flavonoids and phenolic acids) were isolated and 19 were identified in the aerial parts of Triticum aestivum L. The structures of these compounds were established on the basis of the data obtained by electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) techniques. T. aestivum L. was found to be rich in flavones, especially in luteolin derivatives. Three of the isolated compounds, including luteolin 6-C-[6Glc″-O-E-caffeoyl-β-D-glucopyranosyl(1″→2)-β-glucopyranoside], luteolin 6-C-[5Rib″-O-E-feruoyl-β-D-ribofuranosyl(1″→2)-β-glucopyranoside], and 3',4',5'-O-trimethyltricetin 7-O-[β-D-glucuropyranosyl(1″→2)-β-D-glucopyranoside], have been reported for the first time in the plant kingdom. The amount of individual phenolics, in winter wheat, was also determined. Additionally, the free radical scavenging potential of the isolated compounds was tested in a simple and rapid thin-layer chromatography-2,2-diphenyl-1-picrylhydrazyl radical test (TLC-DPPH•) with image processing.

  6. Inhibitory effect on nitric oxide production and free radical scavenging activity of Thai medicinal plants in osteoarthritic knee treatment.

    Science.gov (United States)

    Anuthakoengkun, Areeya; Itharat, Arunporn

    2014-08-01

    Thai medicine plants used for Osteoarthritis of knee (OA) treatment consist of twelve plants such as Crinumn asiaticum, Cleome viscosa, Drypetes roxburghii, Piper longum, Piper nigrum, Plumbago indica, Alpinia galanga, Curcuma aromatica, Globba malaccensis, Zingiber montanum, Zingiber officinale andZingiberzerumbet. They showedhighfrequency in OA formula. To investigate inhibitory effect on LPS-induced nitric oxide (NO) release from RAW264. 7 cell and free radical scavenging activity usingDPPH assay of these ethanolic plant extracts. Plant materials were extracted by maceration in 95% ethanol. Anti-inflammatory activity were tested on LPS-induced NO production. Free radical scavenging activity was performed by DPPH assay. All of ethanolic extracts exhibited potent inhibitory effect on NO release. The ethanolic extract of Z. zerumbet exhibited the highest inhibitory effect followed by Z. montanum and G. malaccensis, respectively. Except A. galanga and C. viscosa, all extracts possessed more influential than indomethacin (IC50 = 20.32±3.23 μLg/ml), a positive control. The investigation on antioxidant activity suggested that the ethanolic extracts of D. roxburghii, Z. officinale, Z. montanum, C. aromatic, A. galanga, P indica, G malaccensis, P nigrum exhibited antioxidant activity. By means ofD. roxburghii had the highest electron donating activity,followed by Z. officinale. Moreover both extracts were more effective than BHT apositive control (EC50 = 14.04±1.95 μg/ml). Thai medicinal plants had anti-inflammatory activity and could inhibit destruction of articular cartilage that corresponded to the traditional medicine and supported using these medicinal plants for OA treatment.

  7. Correlation among Singlet-Oxygen Quenching, Free-Radical Scavenging, and Excited-State Intramolecular-Proton-Transfer Activities in Hydroxyflavones, Anthocyanidins, and 1-Hydroxyanthraquinones.

    Science.gov (United States)

    Nagaoka, Shin-Ichi; Bandoh, Yuki; Nagashima, Umpei; Ohara, Keishi

    2017-10-26

    Singlet-oxygen ( 1 O 2 ) quenching, free-radical scavenging, and excited-state intramolecular proton-transfer (ESIPT) activities of hydroxyflavones, anthocyanidins, and 1-hydroxyanthraquinones were studied by means of laser, stopped-flow, and steady-state spectroscopies. In hydroxyflavones and anthocyanidins, the 1 O 2 quenching activity positively correlates to the free-radical scavenging activity. The reason for this correlation can be understood by considering that an early step of each reaction involves electron transfer from the unfused phenyl ring (B-ring), which is singly bonded to the bicyclic chromen or chromenylium moiety (A- and C-rings). Substitution of an electron-donating OH group at B-ring enhances the electron transfer leading to activation of the 1 O 2 quenching and free-radical scavenging. In 3-hydroxyflavones, the OH substitution at B-ring reduces the activity of ESIPT within C-ring, which can be explained in terms of the nodal-plane model. As a result, the 1 O 2 quenching and free-radical scavenging activities negatively correlate to the ESIPT activity. A catechol structure at B-ring is another factor that enhances the free-radical scavenging in hydroxyflavones. In contrast to these hydroxyflavones, 1-hydroxyanthraquinones having an electron-donating OH substituent adjacent to the O-H---O═C moiety susceptible to ESIPT do not show a simple correlation between their 1 O 2 quenching and ESIPT activities, because the OH substitution modulates these reactions.

  8. The tumor suppressor gene Trp53 protects the mouse lens against posterior subcapsular cataracts and the BMP receptor Acvr1 acts as a tumor suppressor in the lens

    Directory of Open Access Journals (Sweden)

    Luke A. Wiley

    2011-07-01

    We previously found that lenses lacking the Acvr1 gene, which encodes a bone morphogenetic protein (BMP receptor, had abnormal proliferation and cell death in epithelial and cortical fiber cells. We tested whether the tumor suppressor protein p53 (encoded by Trp53 affected this phenotype. Acvr1 conditional knockout (Acvr1CKO mouse fiber cells had increased numbers of nuclei that stained for p53 phosphorylated on serine 15, an indicator of p53 stabilization and activation. Deletion of Trp53 rescued the Acvr1CKO cell death phenotype in embryos and reduced Acvr1-dependent apoptosis in postnatal lenses. However, deletion of Trp53 alone increased the number of fiber cells that failed to withdraw from the cell cycle. Trp53CKO and Acvr1;Trp53DCKO (double conditional knockout, but not Acvr1CKO, lenses developed abnormal collections of cells at the posterior of the lens that resembled posterior subcapsular cataracts. Cells from human posterior subcapsular cataracts had morphological and molecular characteristics similar to the cells at the posterior of mouse lenses lacking Trp53. In Trp53CKO lenses, cells in the posterior plaques did not proliferate but, in Acvr1;Trp53DCKO lenses, many cells in the posterior plaques continued to proliferate, eventually forming vascularized tumor-like masses at the posterior of the lens. We conclude that p53 protects the lens against posterior subcapsular cataract formation by suppressing the proliferation of fiber cells and promoting the death of any fiber cells that enter the cell cycle. Acvr1 acts as a tumor suppressor in the lens. Enhancing p53 function in the lens could contribute to the prevention of steroid- and radiation-induced posterior subcapsular cataracts.

  9. TRP Channels as Therapeutic Targets in Diabetes and Obesity

    Directory of Open Access Journals (Sweden)

    Andrea Zsombok

    2016-08-01

    Full Text Available During the last three to four decades the prevalence of obesity and diabetes mellitus has greatly increased worldwide, including in the United States. Both the short- and long-term forecasts predict serious consequences for the near future, and encourage the development of solutions for the prevention and management of obesity and diabetes mellitus. Transient receptor potential (TRP channels were identified in tissues and organs important for the control of whole body metabolism. A variety of TRP channels has been shown to play a role in the regulation of hormone release, energy expenditure, pancreatic function, and neurotransmitter release in control, obese and/or diabetic conditions. Moreover, dietary supplementation of natural ligands of TRP channels has been shown to have potential beneficial effects in obese and diabetic conditions. These findings raised the interest and likelihood for potential drug development. In this mini-review, we discuss possibilities for better management of obesity and diabetes mellitus based on TRP-dependent mechanisms.

  10. Linear free energy relationships between aqueous phase hydroxyl radical reaction rate constants and free energy of activation.

    Science.gov (United States)

    Minakata, Daisuke; Crittenden, John

    2011-04-15

    The hydroxyl radical (HO(•)) is a strong oxidant that reacts with electron-rich sites on organic compounds and initiates complex radical chain reactions in aqueous phase advanced oxidation processes (AOPs). Computer based kinetic modeling requires a reaction pathway generator and predictions of associated reaction rate constants. Previously, we reported a reaction pathway generator that can enumerate the most important elementary reactions for aliphatic compounds. For the reaction rate constant predictor, we develop linear free energy relationships (LFERs) between aqueous phase literature-reported HO(•) reaction rate constants and theoretically calculated free energies of activation for H-atom abstraction from a C-H bond and HO(•) addition to alkenes. The theoretical method uses ab initio quantum mechanical calculations, Gaussian 1-3, for gas phase reactions and a solvation method, COSMO-RS theory, to estimate the impact of water. Theoretically calculated free energies of activation are found to be within approximately ±3 kcal/mol of experimental values. Considering errors that arise from quantum mechanical calculations and experiments, this should be within the acceptable errors. The established LFERs are used to predict the HO(•) reaction rate constants within a factor of 5 from the experimental values. This approach may be applied to other reaction mechanisms to establish a library of rate constant predictions for kinetic modeling of AOPs.

  11. Thermal Behavior and Free-Radical-Scavenging Activity of Phytic Acid Alone and Incorporated in Cosmetic Emulsions

    Directory of Open Access Journals (Sweden)

    André Luis Máximo Daneluti

    2015-07-01

    Full Text Available Phytic acid is a natural compound widely used as depigmenting agent in cosmetic emulsions. Few studies are available in the literature covering the stability and the antioxidating property of this substance, used alone or into emulsions. Therefore, the purpose of this work was to investigate the thermal behavior and antioxidant properties of phytic acid alone and into cosmetic emulsions. The thermal behavior of this substance was evaluated by thermogravimetry (TG/derivative thermogravimetry (DTG and differential scanning calorimetry (DSC and the free-radical-scavenging activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH. TG/DTG and DSC curves allowed evaluation of the thermal behavior of phytic acid. These results showed that the substance presented four stages of mass loss. Thermal decomposition of the material initiated at 150 °C. Thermal behavior of the cosmetic emulsions detected that the addition of phytic acid decreased the thermal stability of the system. DPPH free-radical-scavenging activity showed that phytic acid incorporated into emulsion had no antioxidant capacity compared to BHT. In summary, we concluded that the thermoanalytical techniques (TG and DSC were efficient and reliable in the characterization of phytic acid alone and incorporated into cosmetic emulsions.

  12. Kinetics and structure-activity relationship of dendritic bridged hindered phenol antioxidants to protect styrene against free radical induced peroxidation

    Science.gov (United States)

    Li, Cui-Qin; Guo, Su-Yue; Wang, Jun; Shi, Wei-Guang; Zhang, Zhi-Qiu; Wang, Peng-Xiang

    2017-12-01

    A series of dendritic poly(amido-amine) (PAMAM) bridged hindered phenols antioxidants were synthesized. The active antioxidant group (3-(3,5-di- tert-butyl-4-hydroxyphenyl)propionic acid) was attached to two generations of PAMAM dendrimers, and their structure was verified by nuclear magnetic resonance (NMR) and fourier transform infrared spectra (FT-IR). The antioxidant abilities of the dendritic phenols to inhibit the oxidation of styrene were evaluated and the relationships between the length of core, the generation of dendrimers and the antioxidant activities were established. The reaction kinetics of scavenging peroxyl radicals was followed by oxygen consumption. The inhibition time ( t inh) values showed the dendritic phenols had the ability of scavenging peroxyl radicals, and that the antioxidant ability increased with the increasing length of the core and the generation. The kinetic analysis demonstrated that dendritic phenols could slow the rate of styrene peroxidation induced by AIBN, as shown by the number of trapping ROO· ( n), and this role was in accordance with that of the t inh values.

  13. In vitro antioxidant capacity and free radical scavenging evaluation of active metabolite constituents of Newbouldia laevis ethanolic leaf extract.

    Science.gov (United States)

    Habu, Josiah Bitrus; Ibeh, Bartholomew Okechukwu

    2015-03-14

    The aim of the present study was to evaluate the in vitro antioxidant and free radical scavenging capacity of bioactive metabolites present in Newbouldia laevis leaf extract. Chromatographic and spectrophotometric methods were used in the study and modified where necessary in the study. Bioactivity of the extract was determined at 10 μg/ml, 50 μg/ml, 100 μg/ml, 200 μg/ml and 400 μg/ml concentrations expressed in % inhibition. The yield of the ethanolic leaf extract of N.laevis was 30.3 g (9.93%). Evaluation of bioactive metabolic constituents gave high levels of ascorbic acid (515.53 ± 12 IU/100 g [25.7 mg/100 g]), vitamin E (26.46 ± 1.08 IU/100 g), saponins (6.2 ± 0.10), alkaloids (2.20 ± 0.03), cardiac glycosides(1.48 ± 0.22), amino acids and steroids (8.01 ± 0.04) measured in mg/100 g dry weight; moderate levels of vitamin A (188.28 ± 6.19 IU/100 g), tannins (0.09 ± 0.30), terpenoids (3.42 ± 0.67); low level of flavonoids (1.01 ± 0.34 mg/100 g) and absence of cyanogenic glycosides, carboxylic acids and aldehydes/ketones. The extracts percentage inhibition of DPPH, hydroxyl radical (OH.), superoxide anion (O2 .-), iron chelating, nitric oxide radical (NO), peroxynitrite (ONOO-), singlet oxygen (1O2), hypochlorous acid (HOCl), lipid peroxidation (LPO) and FRAP showed a concentration-dependent antioxidant activity with no significant difference with the controls. Though, IC50 of the extract showed significant difference only in singlet oxygen (1O2) and iron chelating activity when compared with the controls. The extract is a potential source of antioxidants/free radical scavengers having important metabolites which maybe linked to its ethno-medicinal use.

  14. Functional TRP and ASIC-like channels in cultured urothelial cells from the rat.

    Science.gov (United States)

    Kullmann, F Aura; Shah, M A; Birder, L A; de Groat, W C

    2009-04-01

    Transient receptor potential (TRP) and acid-sensing ion channels (ASIC) are molecular detectors of chemical, mechanical, thermal, and nociceptive stimuli in sensory neurons. They have been identified in the urothelium, a tissue considered part of bladder sensory pathways, where they might play a role in bladder function. This study investigated functional properties of TRP and ASIC channels in cultured urothelial cells from the rat using patch-clamp and fura 2 Ca(2+) imaging techniques. The TRPV4 agonist 4alpha-phorbol-12,13 didecanoate (4alpha-PDD; 1-5 microM) and the TRPA1/TRPM8 agonist icilin (50-100 microM) elicited transient currents in a high percentage of cells (>70%). 4alpha-PDD responses were suppressed by the TRPV4 antagonist HC-010961 (10 microM). The TRPV1 agonist capsaicin (1-100 microM) and the TRPA1/TRPM8 agonist menthol (5-200 microM) elicited transient currents in a moderate percentage of cells ( approximately 25%). All of these agonists increased intracellular calcium concentration ([Ca(2+)](i)). Most cells responded to more than one TRP agonist (e.g., capsaicin and 4alpha-PDD), indicating coexpression of different TRP channels. In the presence of the TRPV1 antagonist capsazepine (10 microM), changes in pH induced by HCl elicited ionic currents (pH 5.5) and increased [Ca(2+)](i) (pH 6.5) in approximately 50% of cells. Changes in pH using acetic acid (pH 5.5) elicited biphasic-like currents. Responses induced by acid were sensitive to amiloride (10 microM). In summary, urothelial cells express multiple TRP and ASIC channels, whose activation elicits ionic currents and Ca(2+) influx. These "neuron-like" properties might be involved in transmitter release, such as ATP, that can act on afferent nerves or smooth muscle to modulate their responses to different stimuli.

  15. Effects of ionic radius of redox-inactive bio-related metal ions on the radical-scavenging activity of flavonoids evaluated using photometric titration.

    Science.gov (United States)

    Waki, Tsukasa; Kobayashi, Shigeki; Matsumoto, Ken-ichiro; Ozawa, Toshihiko; Kamada, Tadashi; Nakanishi, Ikuo

    2013-10-28

    Mg(2+) enhanced the scavenging activity of (+)-catechin and quercetin against the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙), while Al(3+) decreased their activity. Such effects of Mg(2+) and Al(3+) were not observed for kaempferol. Na(+) and Ca(2+) with large ionic radii showed little effect on the DPPH˙-scavenging activity of these three flavonoids.

  16. Radical chemistry of artemisinin

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, Evgenii T; Solodova, S L; Denisova, Taisa G [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

    2011-12-29

    The review summarizes physicochemical characteristics of the natural sesquiterpene peroxide artemisinin. The kinetic schemes of transformations of artemisinin radicals under anaerobic conditions are presented and analyzed. The sequence of radical reactions of artemisinin in the presence of oxygen is considered in detail. Special emphasis is given to the intramolecular chain oxidation resulting in the transformation of artemisinin into polyatomic hydroperoxide. The kinetic characteristics of elementary reaction steps involving alkyl, alkoxyl, and peroxyl radicals generated from artemisinin are discussed. The results of testing of artemisinin and its derivatives for the antimalarial activity and the scheme of the biochemical synthesis of artemisinin in nature are considered.

  17. Radical chemistry of artemisinin

    Science.gov (United States)

    Denisov, Evgenii T.; Solodova, S. L.; Denisova, Taisa G.

    2010-12-01

    The review summarizes physicochemical characteristics of the natural sesquiterpene peroxide artemisinin. The kinetic schemes of transformations of artemisinin radicals under anaerobic conditions are presented and analyzed. The sequence of radical reactions of artemisinin in the presence of oxygen is considered in detail. Special emphasis is given to the intramolecular chain oxidation resulting in the transformation of artemisinin into polyatomic hydroperoxide. The kinetic characteristics of elementary reaction steps involving alkyl, alkoxyl, and peroxyl radicals generated from artemisinin are discussed. The results of testing of artemisinin and its derivatives for the antimalarial activity and the scheme of the biochemical synthesis of artemisinin in nature are considered.

  18. Radical chemistry of artemisinin

    International Nuclear Information System (INIS)

    Denisov, Evgenii T; Solodova, S L; Denisova, Taisa G

    2010-01-01

    The review summarizes physicochemical characteristics of the natural sesquiterpene peroxide artemisinin. The kinetic schemes of transformations of artemisinin radicals under anaerobic conditions are presented and analyzed. The sequence of radical reactions of artemisinin in the presence of oxygen is considered in detail. Special emphasis is given to the intramolecular chain oxidation resulting in the transformation of artemisinin into polyatomic hydroperoxide. The kinetic characteristics of elementary reaction steps involving alkyl, alkoxyl, and peroxyl radicals generated from artemisinin are discussed. The results of testing of artemisinin and its derivatives for the antimalarial activity and the scheme of the biochemical synthesis of artemisinin in nature are considered.

  19. Radical chemistry of artemisinin

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, Evgenii T; Solodova, S L; Denisova, Taisa G [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

    2010-12-29

    The review summarizes physicochemical characteristics of the natural sesquiterpene peroxide artemisinin. The kinetic schemes of transformations of artemisinin radicals under anaerobic conditions are presented and analyzed. The sequence of radical reactions of artemisinin in the presence of oxygen is considered in detail. Special emphasis is given to the intramolecular chain oxidation resulting in the transformation of artemisinin into polyatomic hydroperoxide. The kinetic characteristics of elementary reaction steps involving alkyl, alkoxyl, and peroxyl radicals generated from artemisinin are discussed. The results of testing of artemisinin and its derivatives for the antimalarial activity and the scheme of the biochemical synthesis of artemisinin in nature are considered.

  20. Active vs. spectator modes in nonadiabatic photodissociation dynamics of the hydroxymethyl radical via the 22A(3s) Rydberg state

    Science.gov (United States)

    Xie, Changjian; Guo, Hua

    2018-01-01

    The choice of the active degrees of freedom (DOFs) is a pivotal issue in a reduced-dimensional model of quantum dynamics when a full-dimensional one is not feasible. Here, several five-dimensional (5D) models are used to investigate the nonadiabatic photodissociation dynamics of the hydroxymethyl (CH2OH) radical, which possesses nine internal DOFs, in its lowest absorption band. A normal-mode based scheme is used to identify the active and spectator modes, and its predictions are confirmed by 5D quantum dynamical calculations. Our results underscore the important role of the CO stretching mode in the photodissociation dynamics of CH2OH, originating from the photo-induced promotion of an electron from the half-occupied π*CO antibonding orbital to a carbon Rydberg orbital.

  1. Radical Scavenging and Anti-Inflammatory Activities of Representative Anthocyanin Groupings from Pigment-Rich Fruits and Vegetables

    Directory of Open Access Journals (Sweden)

    Federica Blando

    2018-01-01

    Full Text Available Anthocyanins, the naturally occurring pigments responsible for most red to blue colours of flowers, fruits and vegetables, have also attracted interest because of their potential health effects. With the aim of contributing to major insights into their structure–activity relationship (SAR, we have evaluated the radical scavenging and biological activities of selected purified anthocyanin samples (PASs from various anthocyanin-rich plant materials: two fruits (mahaleb cherry and blackcurrant and two vegetables (black carrot and “Sun Black” tomato, differing in anthocyanin content (ranging from 4.9 to 38.5 mg/g DW and molecular structure of the predominant anthocyanins. PASs from the abovementioned plant materials have been evaluated for their antioxidant capacity using Trolox Equivalent Antioxidant Capacity (TEAC and Oxygen Radical Absorbance Capacity (ORAC assays. In human endothelial cells, we analysed the anti-inflammatory activity of different PASs by measuring their effects on the expression of endothelial adhesion molecules VCAM-1 and ICAM-1. We demonstrated that all the different PASs showed biological activity. They exhibited antioxidant capacity of different magnitude, higher for samples containing non-acylated anthocyanins (typical for fruits compared to samples containing more complex anthocyanins acylated with cinnamic acid derivatives (typical for vegetables, even though this order was slightly reversed when ORAC assay values were expressed on a molar basis. Concordantly, PASs containing non-acylated anthocyanins reduced the expression of endothelial inflammatory antigens more than samples with aromatic acylated anthocyanins, suggesting the potential beneficial effect of structurally diverse anthocyanins in cardiovascular protection.

  2. In-vitro free radical scavenging activity of biosynthesized gold and silver nanoparticles using Prunus armeniaca (apricot) fruit extract

    Energy Technology Data Exchange (ETDEWEB)

    Dauthal, Preeti; Mukhopadhyay, Mausumi, E-mail: mausumi_mukhopadhyay@yahoo.com [S.V. National Institute of Technology, Department of Chemical Engineering (India)

    2013-01-15

    In-vitro free radical scavenging activity of biosynthesized gold (Au-NPs) and silver (Ag-NPs) nanoparticles was investigated in the present study. Natural precursor Prunus armeniaca (apricot) fruit extract was used as a reducing agent for the nanoparticle synthesis. The free radical scavenging activity of the nanoparticles were observed by modified 1,1 Prime -diphynyl-2-picrylhydrazyl, DPPH and 2,2 Prime -azinobis (3-ethylbenzothiazoline-6-sulfonic acid), ABTS assay. The synthesized nanoparticles were characterized by UV-Visible spectroscopy, dynamic light scattering, transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive spectroscopy, and fourier transform infrared spectroscopy (FTIR). Appearance of optical absorption peak at 537 nm (2.20 keV) and 435 nm (3 keV) within 0.08 and 0.5 h of reaction time was confirmed the presence of metallic Au and Ag nanoclusters, respectively. Nearly spherical nanoparticles with majority of particle below 20 nm (TEM) for both Au-NPs and Ag-NPs were synthesized. XRD pattern confirmed the existence of pure nanocrystalline Au-NPs while few additional peaks in the vicinity of fcc silver-speculated crystallization of metalloproteins of fruit extract on the surface of the Ag-NPs and vice versa. FTIR spectra was supported the role of amino acids of protein/enzymes of fruit extract for synthesis and stabilization of nanoparticles. Dose-dependent scavenging activity was observed for Au-NPs and Ag-NPs in both DPPH and ABTS in-vitro assay. 50 % scavenging activity for DPPH were 11.27 and 16.18 mg and for ABTS 3.40 and 7.12 mg with Au-NPs and Ag-NPs, respectively.

  3. Development of an in Silico Model of DPPH• Free Radical Scavenging Capacity: Prediction of Antioxidant Activity of Coumarin Type Compounds

    Directory of Open Access Journals (Sweden)

    Elizabeth Goya Jorge

    2016-06-01

    Full Text Available A quantitative structure-activity relationship (QSAR study of the 2,2-diphenyl-l-picrylhydrazyl (DPPH• radical scavenging ability of 1373 chemical compounds, using DRAGON molecular descriptors (MD and the neural network technique, a technique based on the multilayer multilayer perceptron (MLP, was developed. The built model demonstrated a satisfactory performance for the training ( R 2 = 0.713 and test set ( Q ext 2 = 0.654 , respectively. To gain greater insight on the relevance of the MD contained in the MLP model, sensitivity and principal component analyses were performed. Moreover, structural and mechanistic interpretation was carried out to comprehend the relationship of the variables in the model with the modeled property. The constructed MLP model was employed to predict the radical scavenging ability for a group of coumarin-type compounds. Finally, in order to validate the model’s predictions, an in vitro assay for one of the compounds (4-hydroxycoumarin was performed, showing a satisfactory proximity between the experimental and predicted pIC50 values.

  4. TrpA1 Regulates Defecation of Food-Borne Pathogens under the Control of the Duox Pathway.

    Directory of Open Access Journals (Sweden)

    Eun Jo Du

    2016-01-01

    Full Text Available Pathogen expulsion from the gut is an important defense strategy against infection, but little is known about how interaction between the intestinal microbiome and host immunity modulates defecation. In Drosophila melanogaster, dual oxidase (Duox kills pathogenic microbes by generating the microbicidal reactive oxygen species (ROS, hypochlorous acid (HOCl in response to bacterially excreted uracil. The physiological function of enzymatically generated HOCl in the gut is, however, unknown aside from its anti-microbial activity. Drosophila TRPA1 is an evolutionarily conserved receptor for reactive chemicals like HOCl, but a role for this molecule in mediating responses to gut microbial content has not been described. Here we identify a molecular mechanism through which bacteria-produced uracil facilitates pathogen-clearing defecation. Ingestion of uracil increases defecation frequency, requiring the Duox pathway and TrpA1. The TrpA1(A transcript spliced with exon10b (TrpA1(A10b that is present in a subset of midgut enteroendocrine cells (EECs is critical for uracil-dependent defecation. TRPA1(A10b heterologously expressed in Xenopus oocytes is an excellent HOCl receptor characterized with elevated sensitivity and fast activation kinetics of macroscopic HOCl-evoked currents compared to those of the alternative TRPA1(A10a isoform. Consistent with TrpA1's role in defecation, uracil-excreting Erwinia carotovora showed higher persistence in TrpA1-deficient guts. Taken together, our results propose that the uracil/Duox pathway promotes bacteria expulsion from the gut through the HOCl-sensitive receptor, TRPA1(A10b, thereby minimizing the chances that bacteria adapt to survive host defense systems.

  5. Biomineralization-Inspired Synthesis of Cerium-Doped Carbonaceous Nanoparticles for Highly Hydroxyl Radical Scavenging Activity

    Science.gov (United States)

    Zou, Shenqiang; Zhu, Xiaofang; Zhang, Lirong; Guo, Fan; Zhang, Miaomiao; Tan, Youwen; Gong, Aihua; Fang, Zhengzou; Ju, Huixiang; Wu, Chaoyang; Du, Fengyi

    2018-03-01

    Cerium oxide nanoparticles recently have received extensive attention in biomedical applications due to their excellent anti-oxidation performance. In this study, a simple, mild, and green approach was developed to synthesize cerium-doped carbonaceous nanoparticles (Ce-doped CNPs) using bio-mineralization of bull serum albumin (BSA) as precursor. The resultant Ce-doped CNPs exhibited uniform and ultrasmall morphology with an average size of 14.7 nm. XPS and FTIR results revealed the presence of hydrophilic group on the surface of Ce-doped CNPs, which resulted in excellent dispersity in water. The CCK-8 assay demonstrated that Ce-doped CNPs possessed favorable biocompatibility and negligible cytotoxicity. Using H2O2-induced reactive oxygen species (ROS) as model, Ce-doped CNPs showed highly hydroxyl radical scavenging capability. Furthermore, flow cytometry and live-dead staining results indicated that Ce-doped CNPs protected cells from H2O2-induced damage in a dose-dependent effect, which provided a direct evidence for anti-oxidative performance. These findings suggest that Ce-doped CNPs as novel ROS scavengers may provide a potential therapeutic prospect in treating diseases associated with oxidative stress.

  6. Antimicrobial activity of hydroxyl radicals generated by hydrogen peroxide photolysis against Streptococcus mutans biofilm.

    Science.gov (United States)

    Nakamura, Keisuke; Shirato, Midori; Kanno, Taro; Örtengren, Ulf; Lingström, Peter; Niwano, Yoshimi

    2016-10-01

    Prevention of dental caries with maximum conservation of intact tooth substance remains a challenge in dentistry. The present study aimed to evaluate the antimicrobial effect of H2O2 photolysis on Streptococcus mutans biofilm, which may be a novel antimicrobial chemotherapy for treating caries. S. mutans biofilm was grown on disk-shaped hydroxyapatite specimens. After 1-24 h of incubation, growth was assessed by confocal laser scanning microscopy and viable bacterial counting. Resistance to antibiotics (amoxicillin and erythromycin) was evaluated by comparing bactericidal effects on the biofilm with those on planktonic bacteria. To evaluate the effect of the antimicrobial technique, the biofilm was immersed in 3% H2O2 and was irradiated with an LED at 365 nm for 1 min. Viable bacterial counts in the biofilm were determined by colony counting. The thickness and surface coverage of S. mutans biofilm increased with time, whereas viable bacterial counts plateaued after 6 h. When 12- and 24-h-old biofilms were treated with the minimum concentration of antibiotics that killed viable planktonic bacteria with 3 log reduction, their viable counts were not significantly decreased, suggesting the biofilm acquired antibiotic resistance by increasing its thickness. By contrast, hydroxyl radicals generated by photolysis of 3% H2O2 effectively killed S. mutans in 24-h-old biofilm, with greater than 5 log reduction. The technique based on H2O2 photolysis is a potentially powerful adjunctive antimicrobial chemotherapy for caries treatment. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  7. Free Radical Scavenging Activity of Crude Extracts and 4´-O ...

    African Journals Online (AJOL)

    Olaleye

    this plant to promote good health. (Afr. J. Biomed. ... (Tagliaferro et al, 2002); myricetin, from red wine .... Key: (+++) denotes strong antioxidant activity; (++) denotes moderate antioxidant activity; (+) denotes ..... consumed in the Netherlands.

  8. Activators generated by electron transfer for atom transfer radical polymerization of styrene in the presence of mesoporous silica nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Khezri, Khezrollah, E-mail: kh.khezri@ut.ac.ir [School of Chemistry, University College of Science, University of Tehran, PO Box 14155-6455, Tehran (Iran, Islamic Republic of); Roghani-Mamaqani, Hossein [Department of Polymer Engineering, Sahand University of Technology, PO Box 51335-1996, Tabriz (Iran, Islamic Republic of)

    2014-11-15

    Graphical abstract: Effect of mesoporous silica nanoparticles (MCM-41) on the activator generated by electron transfer for atom transfer radical polymerization (AGET ATRP) is investigated. Decrement of conversion and number average molecular weight and also increment of polydispersity index (PDI) values are three main results of addition of MCM-41 nanoparticles. Incorporation of MCM-41 nanoparticles in the polystyrene matrix can clearly increase thermal stability and decrease glass transition temperature of the nanocomposites. - Highlights: • Spherical morphology, hexagonal structure, and high surface area with regular pore diameters of the synthesized MCM-41 nanoparticles are examined. • AGET ATRP of styrene in the presence of MCM-41 nanoparticles is performed. • Effect of MCM-41 nanoparticles addition on the polymerization rate, conversion and molecular weights of the products are discussed. • Improvement in thermal stability of the nanocomposites and decreasing T{sub g} values was also observed by incorporation of MCM-41 nanoparticles. - Abstract: Activator generated by electron transfer for atom transfer radical polymerization was employed to synthesize well-defined mesoporous silica nanoparticles/polystyrene composites. Inherent features of spherical mesoporous silica nanoparticles were evaluated by nitrogen adsorption/desorption isotherm, X-ray diffraction and scanning electron microscopy analysis techniques. Conversion and molecular weight evaluations were carried out using gas and size exclusion chromatography respectively. By the addition of only 3 wt% mesoporous silica nanoparticles, conversion decreases from 81 to 58%. Similarly, number average molecular weight decreases from 17,116 to 12,798 g mol{sup −1}. However, polydispersity index (PDI) values increases from 1.24 to 1.58. A peak around 4.1–4.2 ppm at proton nuclear magnetic resonance spectroscopy results clearly confirms the living nature of the polymerization. Thermogravimetric

  9. [Effect of melaxen on free radical processes intensity and some antioxidant enzymes activity in rats liver and blood serum under type 2 diabetes mellitus].

    Science.gov (United States)

    Verevkin, A N; Popova, T N; Agarkov, A A; Semenikhina, A V

    2015-01-01

    The effect of melaxen on free radical processes and activity of superoxide dismutase and catalase in rats with type 2 diabetes mellitus (T2DM) has been investigated. It was established that melaxen administration to diabetic rats caused a decrease of the intensity of free radical processes as evidenced a decrease of the lipid peroxidation primary products content and biochemiluminescence parameters. The activity of the antioxidant enzymes changed towards normal values. These effects were probably induced by the correction of the melatonin level at the result of the melaxen action.

  10. Reactions of inorganic free radicals with liver protecting drugs

    International Nuclear Information System (INIS)

    Gyoergy, I.; Foeldiak, G.; Blazovics, A.; Feher, J.

    1990-01-01

    Liver protecting drugs, silibinin, a flavonolignane, and the dihydroquinoline derivatives, CH 402 and MTDQ-DA, were shown to inhibit processes in which enzymatically or non-enzymatically generated free radicals were involved. Inorganic free radicals (N 3 , (SCN) 2 - , OH, Trp, CO 2 - , O 2 - ) produced by pulse radiolysis readily react with the compounds, which transform into exceptionally long-lived, unreactive transients. Time evolution of the UV and visible spectra indicate that oxidising radicals form a phenoxyl type radical from silibinin, while OH forms an adduct by attacking, simultaneously, at various sites of the molecule. Superoxide radicals reduce silibinin and oxidise CH 402 and MTDQ-DA. It is concluded that the drugs might exhibit antioxidant behavior in living systems. (author)

  11. Radical Evil

    Directory of Open Access Journals (Sweden)

    Carlos Manrique

    2007-12-01

    Full Text Available There is an aporia in Kant’s analysis of evil: he defines radical evilas an invisible disposition of the will, but he also demands an inferential connection between visible evil actions and this invisible disposition. This inference,however, undermines the radical invisibility of radical evil according to Kant’s own definition of the latter. Noting how this invisibility of moral worth is a distinctive feature of Kant’s approach to the moral problem, the paper then asks why, in the Groundwork, he nonetheless forecloses a question about evil that seems to be consistent with this approach. It is argued that to account for this aporia and this foreclosure, one has to interrogate the way in which the category of religion orients Kant’s incipient philosophy of history in Die Religion.

  12. A Quantum Chemical and Statistical Study of Phenolic Schiff Bases with Antioxidant Activity against DPPH Free Radical

    Directory of Open Access Journals (Sweden)

    El Hassane Anouar

    2014-04-01

    Full Text Available Phenolic Schiff bases are known as powerful antioxidants. To select the electronic, 2D and 3D descriptors responsible for the free radical scavenging ability of a series of 30 phenolic Schiff bases, a set of molecular descriptors were calculated by using B3P86 (Becke’s three parameter hybrid functional with Perdew 86 correlation functional combined with 6-31 + G(d,p basis set (i.e., at the B3P86/6-31 + G(d,p level of theory. The chemometric methods, simple and multiple linear regressions (SLR and MLR, principal component analysis (PCA and hierarchical cluster analysis (HCA were employed to reduce the dimensionality and to investigate the relationship between the calculated descriptors and the antioxidant activity. The results showed that the antioxidant activity mainly depends on the first and second bond dissociation enthalpies of phenolic hydroxyl groups, the dipole moment and the hydrophobicity descriptors. The antioxidant activity is inversely proportional to the main descriptors. The selected descriptors discriminate the Schiff bases into active and inactive antioxidants.

  13. Is TrpM5 a reliable marker for chemosensory cells? Multiple types of microvillous cells in the main olfactory epithelium of mice

    Directory of Open Access Journals (Sweden)

    Finger Thomas E

    2008-12-01

    Full Text Available Abstract Background In the past, ciliated receptor neurons, basal cells, and supporting cells were considered the principal components of the main olfactory epithelium. Several studies reported the presence of microvillous cells but their function is unknown. A recent report showed cells in the main olfactory epithelium that express the transient receptor potential channel TrpM5 claiming that these cells are chemosensory and that TrpM5 is an intrinsic signaling component of mammalian chemosensory organs. We asked whether the TrpM5-positive cells in the olfactory epithelium are microvillous and whether they belong to a chemosensory system, i.e. are olfactory neurons or trigeminally-innervated solitary chemosensory cells. Results We investigated the main olfactory epithelium of mice at the light and electron microscopic level and describe several subpopulations of microvillous cells. The ultrastructure of the microvillous cells reveals at least three morphologically different types two of which express the TrpM5 channel. None of these cells have an axon that projects to the olfactory bulb. Tests with a large panel of cell markers indicate that the TrpM5-positive cells are not sensory since they express neither neuronal markers nor are contacted by trigeminal nerve fibers. Conclusion We conclude that TrpM5 is not a reliable marker for chemosensory cells. The TrpM5-positive cells of the olfactory epithelium are microvillous and may be chemoresponsive albeit not part of the sensory apparatus. Activity of these microvillous cells may however influence functionality of local elements of the olfactory system.

  14. In vitro Antimicrobial, Cytotoxic and Radical Scavenging Activities and Chemical Constituents of the Endemic Thymus laevigatus (Vahl

    Directory of Open Access Journals (Sweden)

    Mohamed Al-Fatimi

    2010-01-01

    Full Text Available The leaves of Thymus laevigatus (Vahl, Lamiaceae (Labiatae, an endemic species of Yemen, are traditionally used in the treatment of various disorders including stomach and respiratory system. In a first biological and chemical study of this endemic species we investigated antimicrobial, cytotoxic and antioxidant activities of different extracts of the leaves of this plant. The preliminary phytochemical screening of extracts composition was performed by TLC while the composition of the essential oil was determined by GC-MS. Twelve constituents were detected from the essential oil, which constituted 99.6 % of the total amount. The major constituents of the oil were: carvacrol (84.3 %, p-cymene (4.1 % p-mentha-1, 4-diene (4.0 % and trans-anethole (3.6%. The main active components were identified by TLC as carvacrol and anethole for dichloromethane extract and as non-volatile phenols and flavonoids for the methanol extract. The methanol, dichloromethane and aqueous extracts were tested for their antimicrobial activities against five bacteria strains and six human pathogenic fungi. Both methanol and dichloromethane showed strong activities against most human pathogenic strains. In the contrast, methanol extract showed broader and stronger antibacterial activities than the dichloromethane extract, especially against the Gram-negative bacterium Pseudomonas aeruginosa. The methanol extract showed the same strong radical scavenging activity in the DPPH assay (14.9mg/ml, when compared to the standard antioxidant, ascorbic acid. In contrast, the cytotoxic activity of the methanol against FL cells, a human amniotic epithelial cell line, was only moderate (IC50 298, 8 mg/ml. On the contrary, the water extract did not show any biological activity. Results presented here suggest that the essential oil and extracts of Thymus laevigatus possess strong antimicrobial and antioxidant properties, and therefore, they can be used as a natural preservative ingredient

  15. DPPH RADICAL SCAVENGING ACTIVITY OF AQUEOUS FRACTION FROM ETHANOLIC EXTRACT OF TALOK FRUIT (Muntingia calabura L.

    Directory of Open Access Journals (Sweden)

    Tatang Irianti

    2016-04-01

    Full Text Available The investigation of talok fruits (Muntingia calabura L. was shown the antioxidant activity of aqueous fraction of the ethanolic extract is relatively low. Hydrolysis treatment has increased the antioxidant activity by releasing the flavonoid aglycone from glycoside form. This study aims to determine the effect of acid and alkaline hydrolysis, and hydrolysis time on the antioxidant activity of aqueous fraction of calabura fruits ethanolic extract. The antioxidant activity of acid hydrolyzed aqueous fractions in 1 and 3h hydrolysis, respectively 9.5 and 1.5 times more potent than the aqueous fraction, while the alkaline in 1 and 3h hydro-lysis were 2.5 and 6.5 times. Flavonoid aglycone liberated on acid hydrolysis and alkaline had different anti-oxidant activity. The value of IC50 by acid hydrolyzed aqueous fraction in 1h and 3h hydrolysis of 20.55 and 97.88μg/mL, while the alkaline in 1h and 3h hydrolysis of 66.64 and 25.53μg/mL. One hour acid hydrolysis had antioxidant activity greater than 3h whereas in alkaline the greatest antioxidant activity is shown in 3h.

  16. Rate Constants and Activation Energies for Gas-Phase Reactions of Three Cyclic Volatile Methyl Siloxanes with the Hydroxyl Radical.

    Science.gov (United States)

    Safron, Andreas; Strandell, Michael; Kierkegaard, Amelie; Macleod, Matthew

    2015-07-01

    Reaction with hydroxyl radicals (OH) is the major pathway for removal of cyclic volatile methyl siloxanes (cVMS) from air. We present new measurements of second-order rate constants for reactions of the cVMS octamethylcyclotetrasiloxane (D 4 ), decamethylcyclopentasiloxane (D 5 ), and dodecamethylcyclohexasiloxane (D 6 ) with OH determined at temperatures between 313 and 353 K. Our measurements were made using the method of relative rates with cyclohexane as a reference substance and were conducted in a 140-mL gas-phase reaction chamber with online mass spectrometry analysis. When extrapolated to 298 K, our measured reaction rate constants of D 4 and D 5 with the OH radical are 1.9 × 10 -12 (95% confidence interval (CI): (1.7-2.2) × 10 -12 ) and 2.6 × 10 -12 (CI: (2.3-2.9) × 10 -12 ) cm 3 molecule -1 s -1 , respectively, which are 1.9× and 1.7× faster than previous measurements. Our measured rate constant for D 6 is 2.8 × 10 -12 (CI: (2.5-3.2) × 10 -12 ) cm 3 molecule -1 s -1 and to our knowledge there are no comparable laboratory measurements in the literature. Reaction rates for D 5 were 33% higher than for D 4 (CI: 30-37%), whereas the rates for D 6 were only 8% higher than for D 5 (CI: 5-10%). The activation energies of the reactions of D 4 , D 5 , and D 6 with OH were not statistically different and had a value of 4300 ± 2800 J/mol.

  17. Rate Constants and Activation Energies for Gas‐Phase Reactions of Three Cyclic Volatile Methyl Siloxanes with the Hydroxyl Radical

    Science.gov (United States)

    Safron, Andreas; Strandell, Michael; Kierkegaard, Amelie

    2015-01-01

    ABSTRACT Reaction with hydroxyl radicals (OH) is the major pathway for removal of cyclic volatile methyl siloxanes (cVMS) from air. We present new measurements of second‐order rate constants for reactions of the cVMS octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) with OH determined at temperatures between 313 and 353 K. Our measurements were made using the method of relative rates with cyclohexane as a reference substance and were conducted in a 140‐mL gas‐phase reaction chamber with online mass spectrometry analysis. When extrapolated to 298 K, our measured reaction rate constants of D4 and D5 with the OH radical are 1.9 × 10−12 (95% confidence interval (CI): (1.7–2.2) × 10−12) and 2.6 × 10−12 (CI: (2.3–2.9) × 10−12) cm3 molecule−1 s−1, respectively, which are 1.9× and 1.7× faster than previous measurements. Our measured rate constant for D6 is 2.8 × 10−12 (CI: (2.5–3.2) × 10−12) cm3 molecule−1 s−1 and to our knowledge there are no comparable laboratory measurements in the literature. Reaction rates for D5 were 33% higher than for D4 (CI: 30–37%), whereas the rates for D6 were only 8% higher than for D5 (CI: 5–10%). The activation energies of the reactions of D4, D5, and D6 with OH were not statistically different and had a value of 4300 ± 2800 J/mol. PMID:27708500

  18. Chemical characterization and radical scavenging activity of leaves of Juniperus foetidisima, J. excelsa and J. communis from Macedonian flora

    Directory of Open Access Journals (Sweden)

    Marija Karapandzova

    2014-12-01

    Full Text Available Chemical characterization of three Juniperus species: J. foetidisima (JF, J. excelsa (JE and J. communis (JC from Macedonian flora enclosed determination of yield and essential oil composition of the oils obtained by hydro-distillation of dried leaves and determination of the content of total phenols and total flavonoids in dried plant material. GC/FID/MS analysis showed mainly monoterpene profile of the JC oil and combined monoterpene/sesquiterpene profile of JF and JE oils. Sesquiterpene cedrol was found as an important constituent of the JF and JE, thus the JF oil was characterized by three main components (a-pinene, limonene and cedrol, in amount up to 67.63%, 27.11% and 33.91%, respectively and JE oil by four components (a-pinene, sabinene, cis-thujone and cedrol, in amount up to 33.83%, 29.49%, 26.20% and 24.44%, respectively. The JC oil was free of cedrol, but contained relatively large sesquiterpene fraction (sesquiterpene hydrocarbons and oxygen containing sesquiterpenes in amounts up to 28.64% and 13.57%, respectively. The JC oil was characterized by three monoterpene components (a-pinene, sabinene and terpinen-4-ol, presented up to 28.68%, 16.27% and 12.16%, respectively. The content of total phenols determined by Folin-Ciocalteu method ranged from 96.18-122.91 mg GAE/g dw (water extraction while the content of total flavonoids ranged from 2.05-11.91 mg CE/g dw (ethanol extraction. Both water and ethanol extracts possessed radical scavenging activity against DPPH radical. Water extracts were more powerful with % of inhibition of DPPH ranging up to 64.52%, 67.40% and 78.23% for water extract (10 mg/ml of JF, JE and JC, respectively. Obtained results showed correlation with the content of total phenols.

  19. The flavonoid content and antiproliferative, hypoglycaemic, anti-inflammatory and free radical scavenging activities of Annona dioica St. Hill

    Directory of Open Access Journals (Sweden)

    Formagio Anelise S N

    2013-01-01

    Full Text Available Abstract Background Annona dioica St. Hill (Annonacaeae is a Brazilian plant used in folk medicine for the treatment of several types of rheumatisms and diarrhoea. The focus of this work was to evaluate the in vitro antiproliferative and antioxidant activity and the in vivo hypoglycaemic and anti-inflammatory activity of A. dioica and identify the principal constituents of this plant. Methods The crude methanol extract (EAD and hexane (HF, chloroform (CF, ethyl acetate (EAF and hydromethanol fractions (HMF were evaluated for free radical scavenging activity using the DPPH assay. The EAD and EAF were assayed for hypoglycaemic activity in rats. The EAD was tested in an antiproliferation assay and for anti-inflammatory effects in paw oedema, in addition to myeloperoxidase activity induced by carrageenan (Cg in mice. The EAF was assayed using chromatographic methods. Results The fractionation of the EAF through chromatographic methods identified derivatives of the flavonoids quercetin and kaempferol. Among all the tested fractions, the ethyl acetate and hydromethanol fractions were the most potent, exhibiting an IC50 of 8.53 and 10.57 μg/mL, respectively, which is comparable to that of the commercial antioxidant butylated hydroxytoluene (BHT. The oral administration of the EAD (100 mg/kg and EAF (15 mg/kg inhibited the increase of glucose levels, resulting in a hypoglycaemic effect. The EAD (30 to 300 mg/kg exhibited an anti-oedematogenic effect in Cg-induced paw oedema in a time- and dose-dependent manner. The results showed a reduction of MPO activity by A. dioica 6 h after the induction of paw oedema at all doses tested with maximal inhibition at 300 mg/kg. Conclusions Our results reveal for the first time that compounds contained in the A. dioica leaves exert anti-inflammatory, hypoglycaemic, antiproliferative, and antioxidant effects. The antioxidant activity may be associated with the presence of flavonoids.

  20. Changes of hydrogen peroxide and radical-scavenging activity of raspberry during osmotic, convective, and freeze-drying.

    Science.gov (United States)

    Novaković, Miroslav M; Stevanović, Snežana M; Gorjanović, Stanislava Ž; Jovanovic, Predrag M; Tešević, Vele V; Janković, Miodrag A; Sužnjević, Desanka Ž

    2011-05-01

    This study was conducted to investigate the influence of different drying treatments on antioxidant (AO) activity and phenolic content of raspberry (Rubus idaeus), cultivar Willamette. Whole raspberry fruits were dried convectively (air-drying), osmotically, and freeze-dried. Acetone-water extracts of fresh and dried raspberries were assessed for total phenolic content by standard Folin-Ciocalteau method. Two AO assays were applied, a recently developed direct current (DC) polarographic assay based on decrease of anodic oxidation current of hydrogen peroxide and widely used radical scavenge against the 1,1-diphenyl-2-picrylhydrazyl (DPPH). Strong correlation has been obtained between both AO assays and total phenolic content. In addition, some individual phenolic compounds present in raspberry have been assessed using DPPH and DC polarographic assay. Comparison and evaluation of drying methods has been based on preservation of AO activity and total phenolic content. Obtained results confirmed superiority of freeze-drying; convective drying caused slight changes while osmotic dehydration showed a significant decrease of phenolic compounds and AO activity. © 2011 Institute of Food Technologists®

  1. Changes of Major Antioxidant Compounds and Radical Scavenging Activity of Palm Oil and Rice Bran Oil during Deep-Frying

    Directory of Open Access Journals (Sweden)

    Azizah Abdul Hamid

    2014-07-01

    Full Text Available Changes in antioxidant properties and degradation of bioactives in palm oil (PO and rice bran oil (RBO during deep-frying were investigated. The alpha (α-tocopherol, gamma (γ-tocotrienol and γ-oryzanol contents of the deep-fried oils were monitored using high performance liquid chromatography, and antioxidant activity was determined using 2-diphenyl-1-picryl hydrazyl (DPPH radical scavenging activity. Results revealed that the antioxidant activity of PO decreased significantly (p < 0.05, while that of RBO was preserved after deep-frying of fries. As expected, the concentration of α-tocopherol in PO and γ-tocotrienol in both PO and RBO decreased significantly (p < 0.05 with increased frying. Results also showed that γ-tocotrienol was found to be more susceptible to degradation compared to that of α-tocopherol in both PO and RBO. Interestingly, no significant degradation of α-tocopherol was observed in RBO. It is suggested that the presence of γ-oryzanol and γ-tocotrienol in RBO may have a protective effect on α-tocopherol during deep-frying.

  2. Assessing the fatty acid, essential oil composition, their radical scavenging and antibacterial activities of Schinus terebinthifolius Raddi leaves and twigs.

    Science.gov (United States)

    Ennigrou, Asma; Casabianca, Hervé; Vulliet, Emmanuelle; Hanchi, Belgacem; Hosni, Karim

    2018-04-01

    The fatty acid, essential oil compositions and their respective antioxidant and antibacterial activities was determined in Schinus terebinthifolius Raddi leaves and twigs. The lipid content ranged from 1.75 to 4.65% in twigs and leaves, respectively. Thirteen fatty acids were identified with α-linolenic (C18:3), palmitic (C16:0) and linoleic (C18:2) acids being the main components. The essential oils of both organs were characterized by a high amount of monoterpene hydrocarbons (68.91-74.88%) with α-phellandrene (33.06-36.18%), α-pinene (14.85-15.18%) and limonene (6.62-8.79%) being the chief components. The DPPH˙ radical scavenging assay revealed that both oils have a very weak antiradical activity. In contrast, they showed an appreciable antibacterial activity against the gram-positive Enterococcus feacium (ATCC 19434) and Streptococcus agalactiae (ATCC 13813) bacteria. These results suggest that leaves and twigs of S. terebinthifolius could be considered as an important dietary source of health promoting phytochemicals and has a good potential for use in food industry and pharmacy.

  3. Active peptides from skate (Okamejei kenojei) skin gelatin diminish angiotensin-I converting enzyme activity and intracellular free radical-mediated oxidation.

    Science.gov (United States)

    Ngo, Dai-Hung; Ryu, BoMi; Kim, Se-Kwon

    2014-01-15

    Skin gelatin of skate (Okamejei kenojei) was hydrolyzed using Alcalase, flavourzyme, Neutrase and protamex. It was found that the Alcalase hydrolysate exhibited the highest angiotensin-I converting enzyme (ACE) inhibitory activity. Then, Alcalase hydrolysate was further hydrolyzed with protease and separated by an ultrafiltration membrane system. Finally, two peptides responsible for ACE inhibitory activity were identified to be MVGSAPGVL (829Da) and LGPLGHQ (720Da), with IC50 values of 3.09 and 4.22μM, respectively. Moreover, the free radical-scavenging activity of the purified peptides was determined in human endothelial cells. In addition, the antioxidative mechanism of the purified peptides was evaluated by protein and gene expression levels of antioxidant enzymes. The current study demonstrated that the peptides derived from skate skin gelatin could be used in the food industry as functional ingredients with potent antihypertensive and antioxidant benefits. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Reactive oxygen radicals and gaseous transmitters in carotid body activation by intermittent hypoxia.

    Science.gov (United States)

    Prabhakar, Nanduri R; Peng, Ying-Jie; Yuan, Guoxiang; Nanduri, Jayasri

    2018-05-01

    Sleep apnea is a prevalent respiratory disease characterized by periodic cessation of breathing during sleep causing intermittent hypoxia (IH). Sleep apnea patients and rodents exposed to IH exhibit elevated sympathetic nerve activity and hypertension. A heightened carotid body (CB) chemoreflex has been implicated in causing autonomic abnormalities in IH-treated rodents and in sleep apnea patients. The purpose of this article is to review the emerging evidence showing that interactions between reactive oxygen species (ROS) and gaseous transmitters as a mechanism cause hyperactive CB by IH. Rodents treated with IH exhibit markedly elevated ROS in the CB, which is due to transcriptional upregulation of pro-oxidant enzymes by hypoxia-inducible factor (HIF)-1 and insufficient transcriptional regulation of anti-oxidant enzymes by HIF-2. ROS, in turn, increases cystathionine γ-lyase (CSE)-dependent H 2 S production in the CB. Blockade of H 2 S synthesis prevents IH-evoked CB activation. However, the effects of ROS on H 2 S production are not due to direct effects on CSE enzyme activity but rather due to inactivation of heme oxygenase-2 (HO-2), a carbon monoxide (CO) producing enzyme. CO inhibits H 2 S production through inactivation of CSE by PKG-dependent phosphorylation. During IH, reduced CO production resulting from inactivation of HO-2 by ROS releases the inhibition of CO on CSE thereby increasing H 2 S. Inhibiting H 2 S synthesis prevented IH-evoked sympathetic activation and hypertension.

  5. Remote C−H Activation of Quinolines through Copper-Catalyzed Radical Cross-Coupling

    KAUST Repository

    Xu, Jun; Shen, Chao; Zhu, Xiaolei; Zhang, Pengfei; Ajitha, Manjaly John; Huang, Kuo-Wei; An, Zhongfu; Liu, Xiaogang

    2016-01-01

    Achieving site selectivity in carbon-hydrogen (C-H) functionalization reactions is a formidable challenge in organic chemistry. Herein, we report a novel approach to activating remote C-H bonds at the C5 position of 8-aminoquinoline through copper

  6. Quantum Chemical Investigation on the Antioxidant Activity of Neutral and Anionic Forms of Juglone: Metal Chelation and Its Effect on Radical Scavenging Activity

    Directory of Open Access Journals (Sweden)

    Aymard Didier Fouegue Tamafo

    2017-01-01

    Full Text Available The chelation ability of divalent Mg, Ca, Fe, Co, Ni, Cu, Zn, and monovalent Cu ions by neutral and anionic forms of juglone has been investigated at DFT/B3LYP/6-31+G(d,p level of theory in gas and aqueous phases. It is noteworthy that only the 1 : 1 stoichiometry was considered herein. The effects of these metals on the radical scavenging activity of neutral juglone were evaluated via the usual descriptors of hydrogen atom transfer. According to our results, metal chelation by the two forms of juglone was spontaneous and exothermic in both media. Based on the binding energies, Cu(II ion showed the highest affinity for the ligands. QTAIM analyses identified the metal-ligand bonds as intermediate type interactions in all the chelates, except those of Ca and Mg. It was also found that the chelates were better radical scavengers than the ligands. In the gas phase, the scavenging activity of the compounds was found to be governed by direct hydrogen atom transfer, the Co(II chelate being the most reactive. In the aqueous phase also, the sequential proton loss electron transfer was preferred by all the molecules, while the Cu(II chelates were the most reactive.

  7. Chemical repair activity of free radical scavenger edaravone. Reduction reactions with dGMP hydroxyl radical adducts and suppression of base lesions and AP sites on irradiated plasmid DNA

    International Nuclear Information System (INIS)

    Hata, Kuniki; Katsumura, Yosuke; Urushibara, Ayumi; Yamashita, Shinichi; Lin Mingzhang; Muroya, Yusa; Shikazono, Naoya; Yokoya, Akinari; Fu Haiying

    2015-01-01

    Reactions of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) with deoxyguanosine monophosphate (dGMP) hydroxyl radical adducts were investigated by pulse radiolysis technique. Edaravone was found to reduce the dGMP hydroxyl radical adducts through electron transfer reactions. The rate constants of the reactions were greater than 4 × 10 8 dm 3 mol -1 s -1 and similar to those of the reactions of ascorbic acid, which is a representative antioxidant. Yields of single-strand breaks, base lesions, and abasic sites produced in pUC18 plasmid DNA by gamma ray irradiation in the presence of low concentrations (10–1000 μmol dm -3 ) of edaravone were also quantified, and the chemical repair activity of edaravone was estimated by a method recently developed by the authors. By comparing suppression efficiencies to the induction of each DNA lesion, it was found that base lesions and abasic sites were suppressed by the chemical repair activity of edaravone, although the suppression of single-strand breaks was not very effective. This phenomenon was attributed to the chemical repair activity of edaravone toward base lesions and abasic sites. However, the chemical repair activity of edaravone for base lesions was lower than that of ascorbic acid. (author)

  8. Chemical repair activity of free radical scavenger edaravone: reduction reactions with dGMP hydroxyl radical adducts and suppression of base lesions and AP sites on irradiated plasmid DNA.

    Science.gov (United States)

    Hata, Kuniki; Urushibara, Ayumi; Yamashita, Shinichi; Lin, Mingzhang; Muroya, Yusa; Shikazono, Naoya; Yokoya, Akinari; Fu, Haiying; Katsumura, Yosuke

    2015-01-01

    Reactions of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) with deoxyguanosine monophosphate (dGMP) hydroxyl radical adducts were investigated by pulse radiolysis technique. Edaravone was found to reduce the dGMP hydroxyl radical adducts through electron transfer reactions. The rate constants of the reactions were greater than 4 × 10(8) dm(3) mol(-1) s(-1) and similar to those of the reactions of ascorbic acid, which is a representative antioxidant. Yields of single-strand breaks, base lesions, and abasic sites produced in pUC18 plasmid DNA by gamma ray irradiation in the presence of low concentrations (10-1000 μmol dm(-3)) of edaravone were also quantified, and the chemical repair activity of edaravone was estimated by a method recently developed by the authors. By comparing suppression efficiencies to the induction of each DNA lesion, it was found that base lesions and abasic sites were suppressed by the chemical repair activity of edaravone, although the suppression of single-strand breaks was not very effective. This phenomenon was attributed to the chemical repair activity of edaravone toward base lesions and abasic sites. However, the chemical repair activity of edaravone for base lesions was lower than that of ascorbic acid. © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  9. Free radical scavenging and anti-oxidative activities of an ethanol-soluble pigment extract prepared from fermented Zijuan Pu-erh tea.

    Science.gov (United States)

    Fan, Jiang Ping; Fan, Chong; Dong, Wen Min; Gao, Bin; Yuan, Wei; Gong, Jia Shun

    2013-09-01

    An ethanol-soluble pigment extract was separated from fermented Zijuan Pu-erh tea. The compositions of the ethanol soluble pigment extract were analyzed by high-performance liquid chromatography-tandem mass spectroscopy (HPLC-MS/MS). The extract was prepared into a series of ethanol solutions and analyzed for free radical-scavenging activities (against two free radicals: 1,1-diphenyl-2-picrylhydrazyl (DPPH) and (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)) and in vitro anti-oxidative properties. Electron spin resonance spectroscopy showed that the peaks of DPPH and TEMPO decreased with increasing extract concentration, suggesting that the extract had excellent free radical-scavenging activities. In vitro cell culture suggested that, at 50-200 mg/L, the extract had no measurable effect on the viability of vascular endothelial cells (ECV340) but produced significant protective effects for cells that underwent oxidative injuries due to hydrogen peroxide (H₂O₂) treatment. Compared with the H₂O₂ treatment alone cells group, 200 mg/L of the extract increased the activity of superoxide dismutase (SOD) in cells by 397.3%, and decreased the concentration of malondialdehyde (MDA) and the activity of lactate acid dehydrogenase (LDH) by 47.8% and 69.6%, respectively. These results suggest that the extract has excellent free radical scavenging and anti-oxidative properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Evaluation of antioxidant activity of Ruta graveolens L. extract on inhibition of lipid peroxidation and DPPH radicals and the effects of some external factors on plant extract's potency.

    Directory of Open Access Journals (Sweden)

    S. Mohammadi- Motamed

    2014-01-01

    Full Text Available The antioxidant properties of Ruta graveolens L. were evaluated by two different methods; free radical scavenging using DPPH and inhibition of lipid peroxidation by the ferric thiocyanate method. The IC50 value of the methanol extract in DPPH inhibition was 200.5 μg/mL which was acceptable in comparison with BHT (41.8 μg/mL. In thiocyanate method, the plant extract demonstrated activity as much as BHT in prevention of lipid peroxidation. Increasing the temperature during extraction, significantly decreased the extract power in inhibition of DPPH radicals. The storage time and temperature had no effect on lipid peroxidation inhibition.

  11. Predicting Pathological Features at Radical Prostatectomy in Patients with Prostate Cancer Eligible for Active Surveillance by Multiparametric Magnetic Resonance Imaging.

    Directory of Open Access Journals (Sweden)

    Ottavio de Cobelli

    Full Text Available The aim of this study was to investigate the prognostic performance of multiparametric magnetic resonance imaging (mpMRI and Prostate Imaging Reporting and Data System (PIRADS score in predicting pathologic features in a cohort of patients eligible for active surveillance who underwent radical prostatectomy.A total of 223 patients who fulfilled the criteria for "Prostate Cancer Research International: Active Surveillance", were included. Mp-1.5 Tesla MRI examination staging with endorectal coil was performed at least 6-8 weeks after TRUS-guided biopsy. In all patients, the likelihood of the presence of cancer was assigned using PIRADS score between 1 and 5. Outcomes of interest were: Gleason score upgrading, extra capsular extension (ECE, unfavorable prognosis (occurrence of both upgrading and ECE, large tumor volume (≥ 0.5 ml, and seminal vesicle invasion (SVI. Receiver Operating Characteristic (ROC curves and Decision Curve Analyses (DCA were performed for models with and without inclusion of PIRADS score.Multivariate analysis demonstrated the association of PIRADS score with upgrading (P < 0.0001, ECE (P < 0.0001, unfavorable prognosis (P < 0.0001, and large tumor volume (P = 0.002. ROC curves and DCA showed that models including PIRADS score resulted in greater net benefit for almost all the outcomes of interest, with the only exception of SVI.mpMRI and PIRADS scoring are feasible tools in clinical setting and could be used as decision-support systems for a more accurate selection of patients eligible for AS.

  12. A peroxidase mimic with atom transfer radical polymerization activity constructed through the grafting of heme onto metal-organic frameworks.

    Science.gov (United States)

    Jiang, Wei; Pan, Yue; Yang, Jiebing; Liu, Yong; Yang, Yan; Tang, Jun; Li, Quanshun

    2018-07-01

    Atom transfer radical polymerization (ATRP) has been considered to be an efficient strategy for constructing functional macromolecules owing to its simple operation and versatile monomers, and thus it is of great significance to develop ideal catalysts with higher activity and perfect reusability. We constructed a peroxidase mimic through the grafting of heme onto metal-organic frameworks UiO-66-NH 2 (ZrMOF), namely Heme-ZrMOF. After the systematic characterization of structure, the composite Heme-ZrMOF was demonstrated to possess high peroxidase activity using 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) and 3,3',5,5'-tetramethylbenzidine as substrates. The enzyme mimic was then used as catalysts in the ATRP reactions of different monomers, in which favorable monomer conversion (44.6-98.0%) and product molecular weight (8600-25,600 g/mol) could be obtained. Compared to free heme, Heme-ZrMOF could efficiently achieve the easy separation of heme from the catalytic system and facilitate the ATRP reaction in an aqueous environment to avoid the utilization of organic solvents. In conclusion, the enzyme mimic Heme-ZrMOF could be potentially used as an effective catalyst for preparing well-defined polymers with biomedical applications. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Phenolic compounds from the flowers of Nepalese medicinal plant Aconogonon molle and their DPPH free radical-scavenging activities.

    Science.gov (United States)

    Joshi, Khem Raj; Devkota, Hari Prasad; Watanabe, Takashi; Yahara, Shoji

    2014-01-01

    Eleven phenolic compounds, quercetin (1), quercetin 3-O-β-d-galactopyranoside (2), quercetin 3-O-(6″-O-galloyl)-β-d-galactopyranoside (3), quercetin 3-O-(6″-O-caffeoyl)-β-d-galactopyranoside (4), quercetin 3-O-β-d-glucopyranoside (5), rutin (6) quercetin 3-O-α-l-arabinopyranoside (7), quercetin 3-O-α-l-arabinofuranoside (8), protocatechulic acid (9), gallic acid (10) and chlorogenic acid (11), were isolated from the flowers of Aconogonon molle, a Nepalese medicinal plant. Structures of these compounds were elucidated on the basis of spectroscopic methods. All these compounds were isolated for the first time from flowers, and five compounds (4, 5, 8, 9 and 11) were isolated for the first time from A. molle. All of these isolated compounds were evaluated for their in vitro antioxidant activity by using the 1,1-diphenyl-2-picrylhydrazyl radical-scavenging method. Quercetin (1), quercetin glycosides (2-8) and gallic acid (10) exhibited potent antioxidant activity.

  14. Evaluation of the radical activity in Schinopsis balansae Engl. using 32P

    International Nuclear Information System (INIS)

    Prause, Juan; Marinich, María J.

    2000-01-01

    The study was conducted on a population of quebracho colorado chaqueño (Schinopsis balansae Engl.), the principal forest species of economic value in Argentina's Chaqueño Húmedo Park. Individuals of this species were selected according to their height and trunk diameter (DAP). A solution of KH2 32 PO 4 was applied at two different depths 0.10 m and 0.20 m. For 70 days, the concentration of radioactivity in whole mature leaves in the one year old branches was determined weekly. The presence of physiologically active roots was detected at both depths, but the highest root activity was registered at 0.10 m coinciding with the A soil horizon. (author) [es

  15. Fractionation, amino acid profiles, antimicrobial and free radical scavenging activities of Citrullus lanatus seed protein.

    Science.gov (United States)

    Dash, Priyanka; Ghosh, Goutam

    2017-12-01

    In the present study, a modified Osborne fractionation method was followed to isolate albumin (C alb ), globulin (C glo ), prolamin (C pro ) and glutelin (C glu ) successively from seeds of Citrullus lanatus (watermelon). This research work was undertaken to investigate the antimicrobial and antioxidant activities of isolated protein fractions of C. lanatus seed. Amino acid composition and molecular weight distribution were determined to establish their relationship with antimicrobial and antioxidant activity. Among all the fractions, C pro was found to be most effective against A. baumannii followed by C alb and C glo . The results showed that growth of inhibition of these protein fractions differ significantly from each other (p ≤ 0.05). In view of antioxidant potential, C glo exhibited strongest antioxidant capacity while C glu showed weakest antioxidant potential.

  16. Hydroxyl radical modify amino acids and prevent E. coli growth

    International Nuclear Information System (INIS)

    Zhang, Y.; Davies, K.J.A.

    1986-01-01

    The authors report that hydroxyl radical (/sup ./OH) damage to amino acids (AA) affects their incorporation into E. coli proteins. Modification of AA (Try, Trp, Met, Cys, His, Lys, Asn, Gln) by /sup ./OH was achieved by exposure to 60 Co radiation (1-100 krads at 600 rads/min) in N 2 O saturated water. Following exposure to /sup ./OH, the modified AA were added to suspensions of 8 AA requiring E. coli mutants in M9 medium + glucose. Mutants incubated with the /sup ./OH modified AA underwent less growth than those incubated with unmodified AA; with a declining exponential relationship between /sup ./OH exposure of AA and cell growth. The sensitivity of each AA to modification by /sup ./OH was as follows: Tyr > Trp > Met > Cys > His > Lys > Asn > Gln. Essentially the same pattern was observed for inhibition of mutant growth, which was proportional to the concentration of remaining unmodified (i.e. native) AA. Furthermore, cell growth was restored to normal levels by replenishment of native AA. When AA were irradiated at 50μM and then diluted to concentrations expected to support exponential growth (different for each AA) the radiation doses at which mutant growth was inhibited by 63% were as follows (in krad): Tyr 41, Trp 48, Met 53, Cys 56, His 57, Lys 68, Asn 80, Gln 116. /sup ./OH-modified 3 H-Trp was not a substrate for protein synthesis in Trp requiring mutants but was taken up by the cells. Modified Trp was also not incorporated in cell-free synthesis experiments. No toxicity was observed when wild type E. coli, in M9 medium + glucose, were supplemented with any of the/sup ./OH-modified AA. Thus /sup ./OH-modified AA do not support E. coli growth

  17. Effect of blanching treatments on antioxidant activity of frozen green capsicum (Capsicum annuum L. var bell pepper) using radical scavenging activity (DPPH) assay

    Science.gov (United States)

    Azizzuddin, Norafida; Abdullah, Aminah

    2016-11-01

    Blanching treatments are needed to deactivate enzymes in frozen vegetables. Antioxidant activity using DPPH radical scavenging activity assay were evaluated in steaming, boiling water, and microwave blanching at different temperature, time and microwave power level on frozen green capsicum. Green capsicum was chosen for frozen treatment compared to other capsicum with different maturity index because of the firm texture. The objective of this study was to compare the antioxidant activity of frozen green capsicum between conventional and Oxi Count Kit® assay for DPPH radical scavenging activity. Results showed frozen green capsicum blanched using microwave at high level/90 seconds (sample J) contained higher level of DPPH in both conventional method and Oxi Count Kit® compared to other treatments. However, there were no significant differences between sample J and fresh sample (sample A). Overall, the sequences from highest to lowest in blanching treatments for both DPPH conventional method, and DPPH Oxi Count Kit® were J (microwave high level/90 seconds) > A (Fresh) > H (Microwave Medium Level/120 seconds) > D (Boiling Water 80°C/150 seconds) > K (Microwave High Level/120 seconds) > I (Microwave Medium Level/150 seconds) > F (Microwave Low Level/150 seconds)> B (Steam 100°C/150 seconds) > E (Boiling Water 100°C /120 seconds) > G (Microwave Low Level /180 seconds)> C (Steam 100°C/180 seconds). Almost all frozen green capsicum samples showed no significant differences for comparison between test using DPPH conventional method and Oxi Count Kit®. Frozen storage for 0, and 3rd months showed no significant differences which indicate no changes on antioxidant activity during frozen storage at -18°C.

  18. Lipid nanocarriers based on natural oils with high activity against oxygen free radicals and tumor cell proliferation

    International Nuclear Information System (INIS)

    Lacatusu, I.; Badea, N.; Badea, G.; Oprea, O.; Mihaila, M.A.; Kaya, D.A.; Stan, R.; Meghea, A.

    2015-01-01

    The development of nano-dosage forms of phytochemicals represents a significant progress of the scientific approach in the biomedical research. The aim of this study was to assess the effectiveness of lipid nanocarriers based on natural oils (grape seed oil, fish oil and laurel leaf oil) in counteracting free radicals and combating certain tumor cells. No drug was encapsulated in the nanocarriers. The cytotoxic effect exerted by bioactive nanocarriers against two tumor cells, MDA-MB 231 and HeLa cell lines, and two normal cells, L929 and B16 cell lines, was measured using the MTT assay, while oxidative damage was assessed by measuring the total antioxidant activity using chemiluminescence analysis. The best performance was obtained for nanocarriers based on an association of grape seed and laurel leaf oils, with a capacity to scavenge about 98% oxygen free radicals. A dose of nanocarriers of 5 mg·mL −1 has led to a drastic decrease in tumor cell proliferation even in the absence of an antitumor drug (e.g. about 50% viability for MDA-MB 231 cell line and 60% viability for HeLa cell line). A comparative survival profile of normal and tumor cells, which were exposed to an effective dose of 2.5 mg·mL −1 lipid nanocarriers, has revealed a death rate of 20% for normal B16 cells and of 40% death rate for MDA-MB 231 and HeLa tumor cells. The results in this study imply that lipid nanocarriers based on grape seed oil in association with laurel leaf oil could be a candidate to reduce the delivery system toxicity and may significantly improve the therapeutic efficacy of antitumor drugs in clinical applications. - Highlights: • Functional lipid nanocarriers with unique features and broad spectrum effectiveness • Lipid nanocarriers based on laureal leaf oil (LLO) and grape seed oil (GSO) • Antioxidant activity has reached 98% for nanocarriers containing 25% GSO and 2% LLO. • LLO exerts a significant cytotoxic effect against HeLa and MDA-MB 231 tumor cells. • 50

  19. Lipid nanocarriers based on natural oils with high activity against oxygen free radicals and tumor cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Lacatusu, I.; Badea, N.; Badea, G.; Oprea, O. [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu Street No 1, 011061 Bucharest (Romania); Mihaila, M.A. [Institute of Virusology “Stefan S. Nicolau”, Center of Immunology, Bravu Road, No. 285, 030304 Bucharest (Romania); Kaya, D.A. [Department of Field Crops, Faculty of Agriculture, Mustafa Kemal University, 31030 Antakya, Hatay (Turkey); Stan, R., E-mail: rl_stan2000@yahoo.com [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu Street No 1, 011061 Bucharest (Romania); Meghea, A. [University Politehnica of Bucharest, Faculty of Applied Chemistry and Materials Science, Polizu Street No 1, 011061 Bucharest (Romania)

    2015-11-01

    The development of nano-dosage forms of phytochemicals represents a significant progress of the scientific approach in the biomedical research. The aim of this study was to assess the effectiveness of lipid nanocarriers based on natural oils (grape seed oil, fish oil and laurel leaf oil) in counteracting free radicals and combating certain tumor cells. No drug was encapsulated in the nanocarriers. The cytotoxic effect exerted by bioactive nanocarriers against two tumor cells, MDA-MB 231 and HeLa cell lines, and two normal cells, L929 and B16 cell lines, was measured using the MTT assay, while oxidative damage was assessed by measuring the total antioxidant activity using chemiluminescence analysis. The best performance was obtained for nanocarriers based on an association of grape seed and laurel leaf oils, with a capacity to scavenge about 98% oxygen free radicals. A dose of nanocarriers of 5 mg·mL{sup −1} has led to a drastic decrease in tumor cell proliferation even in the absence of an antitumor drug (e.g. about 50% viability for MDA-MB 231 cell line and 60% viability for HeLa cell line). A comparative survival profile of normal and tumor cells, which were exposed to an effective dose of 2.5 mg·mL{sup −1} lipid nanocarriers, has revealed a death rate of 20% for normal B16 cells and of 40% death rate for MDA-MB 231 and HeLa tumor cells. The results in this study imply that lipid nanocarriers based on grape seed oil in association with laurel leaf oil could be a candidate to reduce the delivery system toxicity and may significantly improve the therapeutic efficacy of antitumor drugs in clinical applications. - Highlights: • Functional lipid nanocarriers with unique features and broad spectrum effectiveness • Lipid nanocarriers based on laureal leaf oil (LLO) and grape seed oil (GSO) • Antioxidant activity has reached 98% for nanocarriers containing 25% GSO and 2% LLO. • LLO exerts a significant cytotoxic effect against HeLa and MDA-MB 231 tumor

  20. Comparison of Biochemical Recurrence-Free Survival after Radical Prostatectomy Triggered by Grade Reclassification during Active Surveillance and in Men Newly Diagnosed with Similar Grade Disease.

    Science.gov (United States)

    Diniz, Clarissa P; Landis, Patricia; Carter, H Ballentine; Epstein, Jonathan I; Mamawala, Mufaddal

    2017-09-01

    We compared biochemical recurrence between men on active surveillance who underwent radical prostatectomy triggered by grade reclassification and men diagnosed with similar grade disease treated with immediate radical prostatectomy. We retrospectively analyzed the records of men who underwent surgery from 1995 to 2015 at our institution. We identified 4 groups, including 94 and 56 men on active surveillance who underwent radical prostatectomy following reclassification to Gleason 7 (3 + 4) or greater (grade groups 2 or greater) and Gleason 7 (3 + 4) (grade group 2), and 3,504 and 1,979 in the immediate prostatectomy group diagnosed with grade group 2 or greater and 2, respectively. Biochemical recurrence was assessed by Kaplan-Meir analysis and a multivariable Cox model. Men on active surveillance had a lower incidence of biochemical recurrence than men in the immediate radical prostatectomy groups for biopsy grade groups 2 or greater and 2 (each p <0.05). One, 5 and 10-year biochemical recurrence-free survival for men in the active surveillance group vs the immediate radical prostatectomy group was 97.9% vs 85.5%, 76.6% vs 65.1% and 69.0% vs 54.2% in biopsy grade groups 2 or greater (p = 0.009) and 96.4% vs 91.2%, 89.6% vs 74.0% and 89.6% vs 63.9%, respectively, in biopsy grade group 2 (p = 0.071). For biopsy grade groups 2 or greater there was no significant difference in the risk of biochemical recurrence between the groups after adjusting for age, biopsy extent of cancer and prostate specific antigen density. Patients on active surveillance reclassified to grade groups 2 or greater are at no greater risk for treatment failure than men newly diagnosed with similar grades. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  1. Trp-cage: Folding free energy landscape in explicit water

    Science.gov (United States)

    Zhou, Ruhong

    2003-11-01

    Trp-cage is a 20-residue miniprotein, which is believed to be the fastest folder known so far. In this study, the folding free energy landscape of Trp-cage has been explored in explicit solvent by using an OPLSAA force field with periodic boundary condition. A highly parallel replica exchange molecular dynamics method is used for the conformation space sampling, with the help of a recently developed efficient molecular dynamics algorithm P3ME/RESPA (particle-particle particle-mesh Ewald/reference system propagator algorithm). A two-step folding mechanism is proposed that involves an intermediate state where two correctly formed partial hydrophobic cores are separated by an essential salt-bridge between residues Asp-9 and Arg-16 near the center of the peptide. This metastable intermediate state provides an explanation for the superfast folding process. The free energy landscape is found to be rugged at low temperatures, and then becomes smooth and funnel-like above 340 K. The lowest free energy structure at 300 K is only 1.50 Å C-RMSD (C-rms deviation) from the NMR structures. The simulated nuclear Overhauser effect pair distances are in excellent agreement with the raw NMR data. The temperature dependence of the Trp-cage population, however, is found to be significantly different from experiment, with a much higher melting transition temperature above 400 K (experimental 315 K), indicating that the current force fields, parameterized at room temperature, need to be improved to correctly predict the temperature dependence.

  2. Superoxide anion radicals induce IGF-1 resistance through concomitant activation of PTP1B and PTEN

    Science.gov (United States)

    Singh, Karmveer; Maity, Pallab; Krug, Linda; Meyer, Patrick; Treiber, Nicolai; Lucas, Tanja; Basu, Abhijit; Kochanek, Stefan; Wlaschek, Meinhard; Geiger, Hartmut; Scharffetter-Kochanek, Karin

    2015-01-01

    The evolutionarily conserved IGF-1 signalling pathway is associated with longevity, metabolism, tissue homeostasis, and cancer progression. Its regulation relies on the delicate balance between activating kinases and suppressing phosphatases and is still not very well understood. We report here that IGF-1 signalling in vitro and in a murine ageing model in vivo is suppressed in response to accumulation of superoxide anions () in mitochondria, either by chemical inhibition of complex I or by genetic silencing of -dismutating mitochondrial Sod2. The -dependent suppression of IGF-1 signalling resulted in decreased proliferation of murine dermal fibroblasts, affected translation initiation factors and suppressed the expression of α1(I), α1(III), and α2(I) collagen, the hallmarks of skin ageing. Enhanced led to activation of the phosphatases PTP1B and PTEN, which via dephosphorylation of the IGF-1 receptor and phosphatidylinositol 3,4,5-triphosphate dampened IGF-1 signalling. Genetic and pharmacologic inhibition of PTP1B and PTEN abrogated -induced IGF-1 resistance and rescued the ageing skin phenotype. We thus identify previously unreported signature events with , PTP1B, and PTEN as promising targets for drug development to prevent IGF-1 resistance-related pathologies. PMID:25520316

  3. Phytochemical Characteristics, Free Radical Scavenging Activities, and Neuroprotection of Five Medicinal Plant Extracts

    Directory of Open Access Journals (Sweden)

    Chia Lin Chang

    2012-01-01

    Full Text Available The objective of this study was to determine phytochemical characteristics, chemiluminescence antioxidant capacities, and neuroprotective effects on PC12 cells for methanol extracts of Spatholobus suberectus, Uncaria rhynchophylla, Alpinia officinarum, Drynaria fortunei, and Crataegus pinnatifida. The C. pinnatifida extract (CPE afforded the greatest yield and total phenolic content. The S. suberectus extract (SSE yielded the greatest total flavonoid content. The U. rhynchophylla extract (URE produced the greatest total tannin content, and the A. officinarum extract (AOE produced the greatest total triterpenoid content. The D. fortunei extract, assayed using horseradish peroxidase-luminol-hydrogen peroxide (H2O2, and AOE using pyrogallol-luminol assay each exhibited better antioxidant activity than the L-ascorbic acid and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid did. The CPE, SSE, and URE presented neurogrowth effects and neuroprotective activities on H2O2-induced PC12 cell death at 0.5–5.0 μg/mL. The CPE represents a promising medicinal plant source for the treatment of H2O2-induced neurodegenerative disease, because of its useful phytochemical characteristics.

  4. Phytochemical Characteristics, Free Radical Scavenging Activities, and Neuroprotection of Five Medicinal Plant Extracts

    Science.gov (United States)

    Chang, Chia Lin; Lin, Che San; Lai, Guia Hung

    2012-01-01

    The objective of this study was to determine phytochemical characteristics, chemiluminescence antioxidant capacities, and neuroprotective effects on PC12 cells for methanol extracts of Spatholobus suberectus, Uncaria rhynchophylla, Alpinia officinarum, Drynaria fortunei, and Crataegus pinnatifida. The C. pinnatifida extract (CPE) afforded the greatest yield and total phenolic content. The S. suberectus extract (SSE) yielded the greatest total flavonoid content. The U. rhynchophylla extract (URE) produced the greatest total tannin content, and the A. officinarum extract (AOE) produced the greatest total triterpenoid content. The D. fortunei extract, assayed using horseradish peroxidase-luminol-hydrogen peroxide (H2O2), and AOE using pyrogallol-luminol assay each exhibited better antioxidant activity than the L-ascorbic acid and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid did. The CPE, SSE, and URE presented neurogrowth effects and neuroprotective activities on H2O2-induced PC12 cell death at 0.5–5.0 μg/mL. The CPE represents a promising medicinal plant source for the treatment of H2O2-induced neurodegenerative disease, because of its useful phytochemical characteristics. PMID:21845204

  5. Antioxidant and DPPH (1,1-diphenyl-2-picrylhydrazyl Free Radical Scavenging Activities of Boniger Acid and Calix[4]arene Derivative

    Directory of Open Access Journals (Sweden)

    E. ERDEM

    2014-07-01

    Full Text Available Diazonium derivative of calix[4]arene has been synthesized using three different synthetic steps. Initially p-tert-butylcalix[4]arene was synthesized with the condensation reaction of p-tert-butylphenol and formaldehyde in basic conditions. Calix[4]arene was obtained after the debutylation reaction of p-tert-butylcalix[4]arene with AlCl3. Calix[4]arene reacted with diazonium salt of Böniger acid to yield the 5,17-[(Bis(azo-bis(5-hydroxy-2,7-naphthalenedisulfonicacid]-25,26,27,28-tetrahydroxy calix[4]arene which has eight free phenolic hydroxyl group. Reaction steps were shown in Fig.1.2,7-naphthalenedisulfonicacid]-25,26,27,28-tetrahydroxy calix[4]arene The antioxidant activity of the Böniger acid and calix[4]aren derivative were determined using β-karotene-linoleic acid system. Moreover, the free radical scavenging activity values were tested with DPPH free radical. The two compounds showed strong antioxidant activity. Total antioxidant activity of Böniger acid and calix[4]aren derivative was determined using β–carotenelinoleic acid model system and was found the antioxidant activity of 84.00% and 85.60 % respectively. The free radical scavenging activities were determined as 83.05% and 84.69 %. Results show that, two compounds has the antioxidant activity. The calix[4]aren derivaties has more higher activity then Boniger acid because of calix[4]aren derivative has much hydroxl groups.

  6. Free Radicals Scavenging Activity of Essential Oils and Different Fractions of Methanol Extract of Zataria Multiflora, Salvia Officinalis, Rosmarinus Officinalis, Mentha Pulegium and Cinnamomum Zeylanicum

    Directory of Open Access Journals (Sweden)

    S Changizi Ashtiani

    2012-04-01

    Full Text Available Introduction: Essential oils and extracts from medicinal plants are regarded as natural food preservatives and health promoting drugs. Considering their antioxidant activity, most of them can prevent oxidative stress. The present study was aimed to evaluate free radicals scavenging activity of essential oils and different fractions of methanol extracts from cinnamon, pennyroyal, black cumin, sage, rosemary and azkand. Methods: Antioxidant property of essential oils and different fractions of these medicinal plants was studied by determining their DPPH(2,2-diphenyl-1-picrylhydrazyl free radicals scavenging activity. Results: There were significant differences among the free radical scavenging activity of studied essential oils and different fractions. Ethyl acetate fractions were identified as the most active fractions than other ones and even synthetic antioxidant (BHT, IC50 value of 239.5μg/ml with the highest activity in Mentha pulegium (47.2 μg/ml μg/ml. Among others, n-hexane fraction of rosemary (969 μg/ml, dichloromethane fraction of rosemary (205.46 μg/ml and zatar (344 μg/ml and aqueous fractions of cinnamon (117.6 μg/ml and sage (321.3 μg/ml exhibited appreciable antioxidant activity. Conclusion: Regarding considerable activity of studied extracts, they have the potential to be used as natural antioxidants in relevant industries.

  7. FREE-RADICAL OXIDATION ACTIVITY IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION WITHOUT Q WAVE TREATED WITH EPROSARTAN OR ENALAPRIL ADDITIONALLY TO THE BASIC THERAPY

    Directory of Open Access Journals (Sweden)

    O. G. Zaylobidinov

    2009-01-01

    Full Text Available Aim. To compare effects of eprosartan and enalapril on free-radical oxidation in patients with acute myocardial infarction (AMI without Q wave.Material and methods. 50 patients (aged 52,8±3,3 y.o. with AMI without Q were involved into the study. Patients were randomized on 2 groups. The first group consisted of 24 patients (51,1±2,4 y.o. which received basic therapy and enalapril (10 mg daily. The second group consisted of 26 patients (53,1±3,0 y.o. which received basic therapy and eprosartan (600 mg daily. Basic therapy included anticoagulants, antiplatelets, beta-blockers, nitrates and statins. Intensity of free-radical oxidation was evaluated by change of serum malonic dialdehyde (MDD concentration. Functional activity of serum enzymes of antioxidatic system (AOS was evaluated by rate of reaction of superoxide dismutase (SOD and catalase (CT.Results. The intensity of free-radical oxidation increased in patients with AMI without Q: high level of MDD and peroxinitrite (ONOO-. Besides activity of AOS enzymes (SOD and CT decreased. Eprosartan reduced intensity of peroxide oxidation more prominently in comparison with enalapril. Both drugs preserved low activity of SOD and CT.Conclusion. Eprosartan was significantly more effective than enalapril in reduction of serum free-radical oxidation in patients with AMI without Q wave during 10 days after hospital admission.

  8. TRP channels and traffic-related environmental pollution-induced pulmonary disease.

    Science.gov (United States)

    Akopian, Armen N; Fanick, E Robert; Brooks, Edward G

    2016-05-01

    Environmental pollutant exposures are major risk factors for adverse health outcomes, with increased morbidity and mortality in humans. Diesel exhaust (DE) is one of the major harmful components of traffic-related air pollution. Exposure to DE affects several physiological systems, including the airways, and pulmonary diseases are increased in highly populated urban areas. Hence, there are urgent needs to (1) create newer and lesser polluting fuels, (2) improve exhaust aftertreatments and reduce emissions, and (3) understand mechanisms of actions for toxic effects of both conventional and cleaner diesel fuels on the lungs. These steps could aid the development of diagnostics and interventions to prevent the negative impact of traffic-related air pollution on the pulmonary system. Exhaust from conventional, and to a lesser extent, clean fuels, contains particulate matter (PM) and more than 400 additional chemical constituents. The major toxic constituents are nitrogen oxides (NOx) and polycyclic aromatic hydrocarbons (PAHs). PM and PAHs could potentially act via transient receptor potential (TRP) channels. In this review, we will first discuss the associations between DE from conventional as well as clean fuel technologies and acute and chronic airway inflammation. We will then review possible activation and/or potentiation of TRP vanilloid type 1 (TRPV1) and ankyrin 1 (TRPA1) channels by PM and PAHs. Finally, we will discuss and summarize recent findings on the mechanisms whereby TRPs could control the link between DE and airway inflammation, which is a primary determinant leading to pulmonary disease.

  9. Determination of free radical scavenging activity from aqueous extract of Curcuma mangga by DPPH method

    Science.gov (United States)

    Indis, N. A.; Kurniawan, F.

    2016-04-01

    Curcuma mangga (mango ginger) belongs to the family of Zingiberaceae. The rhizome of C. mangga are morphologically similar to ginger (Zingiber officinale) with a little mango flavour. C. mangga can growth in tropical areas and easy found in Indonesia. The rhizomes of C. mangga were washed and cut into the small piece, then drying at room temperature for 6 days, and then grinded until get the powder of C. mangga. The powder of C. mangga was extracted with deminerahzed water by maceration for 6 hours. C. mangga extract was analysed with FTIR spectrophotometer to determine its functional groups. C. mangga extract was diluted at various of concentration (5, 10, 25, 50, 100, 250, 500 mg/L) using deminerahzed water. C. mangga extracts were tested the antioxidant activity using 0.002% DPPH at 517nm with UV-Vis spectrophotometer, and the IC50 value of C. mangga extract is 212.70 mg/L.

  10. Determination of free radical scavenging activity from aqueous extract of Curcuma mangga by DPPH method

    International Nuclear Information System (INIS)

    Indis, N A; Kurniawan, F

    2016-01-01

    Curcuma mangga (mango ginger) belongs to the family of Zingiberaceae. The rhizome of C. mangga are morphologically similar to ginger (Zingiber officinale) with a little mango flavour. C. mangga can growth in tropical areas and easy found in Indonesia. The rhizomes of C. mangga were washed and cut into the small piece, then drying at room temperature for 6 days, and then grinded until get the powder of C. mangga. The powder of C. mangga was extracted with deminerahzed water by maceration for 6 hours. C. mangga extract was analysed with FTIR spectrophotometer to determine its functional groups. C. mangga extract was diluted at various of concentration (5, 10, 25, 50, 100, 250, 500 mg/L) using deminerahzed water. C. mangga extracts were tested the antioxidant activity using 0.002% DPPH at 517nm with UV-Vis spectrophotometer, and the IC 50 value of C. mangga extract is 212.70 mg/L. (paper)

  11. Studies on free-radical scavenging activity and identification of active ingredients of different plant crude extracts of Mentha piperita collected from Sur, Sultanate of Oman

    Institute of Scientific and Technical Information of China (English)

    Mohammad Amzad Hossain; Aqeela Said Hamed AL Orimi; Afaf Mohammed Weli; Qasim Al-Riyami; Jamal Nasser Al-Sabahi

    2014-01-01

    Objective: To determine free radical scavenging activity and active chemical ingredients of different plant crude extracts of Mentha piperita (M. piperita). Methods: The dried powder leaves of M. piperita were extracted with polar organic solvent by Soxhlet extractor. The crude extract and its fractions of hexane, chloroform, ethyl acetate and butanol crude extracts were prepared. The antioxidant activity of different crude extracts from M. piperita was carried out by DPPH method with minor modification, and the active chemical ingredients of different plant crude extracts of M. piperita were analyzed by gas chromatography-mass spectrometry (GC-MS). Results: Qualitative analysis of different polarities crude extracts by GC-MS found different types of active organic compounds. The antioxidant activity of different crude extracts were found to be in the order of chloroform extract> butanol extract> ethyl acetate extract> hexane extract>methanol extract. Majority identified compounds in the plant crude extracts by GC-MS were biologically active. Conclusions: Therefore, the isolation, purification, identification and characterization of bioactive compounds from various crude extracts of M. piperita might have ecological significance.

  12. Influence of environmental factors on the contents of active ingredients and radical scavenging property of potentilla fruticosa in the main production areas of China

    International Nuclear Information System (INIS)

    Liu, W.; Yin, D. X.; Wang, D. M.; Li, D. W.

    2015-01-01

    Extracts from Potentilla fruticosa have been applied in traditional medicine and exhibited antioxidant property, but little has been known about the diversity of phytochemicals and properties on this species from different growing environment. This study investigated the influence of environmental factors on the active ingredient contents and radical scavenging property of P. fruticosa from different production areas of China in order to discover a location could produce high-quality resources for pharmaceutical products. The contents of tannin, total flavonoids, and rutin were determined and varied within the range of 7.64 ± 0.43 ∼ 10.68 ± 0.67 percentage, 2.29 ± 0.34 ∼ 5.37 ± 0.36 percentage, and 0.19 ± 0.053 ∼ 0.79 ± 0.125 percentage, respectively. Radical scavenging property was quantified, with the IC /sub 50/ of 7.24 ± 0.423 to 17.23 ± 0.551 μ g mL-1. Principal component analysis, multiple linear stepwise regression analysis, and path analysis were conducted to further analysis the relationship between the variations of active ingredients and radical scavenging capacity and growth environment. The results showed dominant environmental factors for these variations were rapidly available nitrogen, rapidly available phosphorus, pH, July average temperature, and annual sunshine duration. Furthermore, a significant positive correlation was observed between pH, annual sunshine duration and active ingredients and radical scavenging property (p<0.05). Considering the high active ingredient contents and strong radical scavenging property, leaf extracts from P. fruticosa could become useful supplements for pharmaceutical products as a new antioxidant agent, and Huzhu Northern Mountain in Qinghai Province and E-mei Mountain in Sichuan Province were selected as favorable production locations. (author)

  13. Antioxidant and DPPH (1,1-diphenyl-2-picrylhydrazyl Free Radical Scavenging Activities of New the Calix[4]arene-bodipy Derivative

    Directory of Open Access Journals (Sweden)

    E. ERDEM

    2014-07-01

    Full Text Available p-tert-butylcalix[4]arene was synthesized with the condesation reaction of p-tert-butylphenol and formaldehyde in basic conditions and then has derivatized from the both of two hydroxyl position with chloride which is containing donor oxygen atoms. BODIPY compound (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene was synthesized with appropriate pyrrole and aldehyde compounds and then was bonded p-tert-butylcalix[4]arene derivative via lower rim hydroxyl groups.The antioxidant activity of the calix[4]arene-BODIPY compound were determined using β-karotene-linoleic acid system. Moreover, the free radical scavenging activity values were tested with DPPH free radical. The compound showed strong antioxidant activity.Total antioxidant activity of the compound was determined using β–carotenelinoleic acid model system and was found the antioxidant activity of 72,50%. The free radical scavenging activities were determined as 75.19%. Results show that, calix[4]arene-BODIPY compound has the antioxidant activity

  14. Localization of higher grade tumor foci in potential candidates for active surveillance who opt for radical prostatectomy

    Science.gov (United States)

    Hong, Sung Kyu; Eastham, James A.; Fine, Samson W.

    2013-01-01

    Purpose: To investigate actual intraprostatic location of higher graded tumor foci undetected via standard transrectal ultrasound-guided prostate biopsy amongst patients who would be clinically considered appropriate candidates for active surveillance (AS) but underwent radical prostatectomy (RP). Methods: We reviewed entirely-submitted and whole-mounted RP specimens from 169 men who were deemed appropriate for AS clinically, but opted for RP and were found to have higher grade tumors. For each case, tumor nodules were circled and color-coded in a grade-specific manner and digitally scanned to created tumor maps. The locations of tumor foci with Gleason grade ≥4 were stratified by specific sites: anterior, anterolateral, lateral only (not clearly anterior or posterior), posterior, and posterolateral area. Results: Of 169 patients, 86% had clinical stage T1c and 14% T2a. RP Gleason score 7 in all but two men. Higher-grade tumor foci were localized to: anterior (n=66, 39%), anterolateral (n=4, 2%), lateral only (not clearly anterior or posterior) (n=5, 3%), posterior (n=52, 31%), and posterolateral (n=42, 25%) prostate, respectively. Conclusions: Among patients deemed clinically appropriate for AS, higher-grade tumor foci missed by standard prostate biopsies were localized to both the anterior and posterior prostate, without predominance of a particular area. These findings lend additional support to performing repeat standard prostate biopsy in potential candidates for AS and should be considered in efforts to optimize current biopsy strategies for the selection of AS patients. PMID:24392439

  15. Sexuality Following Radical Prostatectomy

    DEFF Research Database (Denmark)

    Fode, Mikkel; Serefoglu, Ege C; Albersen, Maarten

    2017-01-01

    incontinence in relation to sexual activity after surgery. This can present at the time of orgasm (ie, climacturia) or arise during arousal. In general, the problem subsides with time and pelvic floor training and tension penile loops can be used as treatments. Orgasmic disturbances after radical prostatectomy...

  16. Active patient decision making regarding nerve sparing during radical prostatectomy: a novel approach.

    Science.gov (United States)

    Lavery, Hugh J; Prall, David N; Abaza, Ronney

    2011-08-01

    The motivation to preserve sexual function can vary widely among patients before prostatectomy. Increasing patient involvement may allow a more personalized experience and may improve satisfaction. We assessed a strategy of surgeon deference to patient choice in regard to nerve sparing to determine to what degree patients are rational actors and capable of active decision making. A total of 150 patients treated with prostatectomy participated in a standardized preoperative discussion regarding the concept of nerve sparing, extracapsular extension and the potential need for adjuvant radiation in the event of local recurrence. Each patient was given his nomogram predicted risk of extracapsular extension and then elected nerve sparing or nonnerve sparing. The corresponding procedure was performed unless grossly invasive disease was encountered. Of the 150 patients 109 chose nerve sparing (73%) and 41 chose nonnerve sparing (27%). In patients with a nomogram predicted risk of extracapsular extension less than 20%, 20% to 50% and greater than 50%, nerve sparing was elected by 88%, 41% and 25%, respectively. Patients with lower risks of extracapsular extension electing nonnerve sparing were older and had higher rates of erectile dysfunction. Empowering patients to decide on their nerve sparing status is a reasonable strategy that did not lead to a high rate of patients with a high risk of extracapsular extension electing nerve sparing. With proper counseling informed patients made reasonable decisions, and appeared to be conservative, prioritizing cancer control in the majority of instances where extracapsular extension risk was high. In addition, they may have been overly conservative in electing nonnerve sparing when the risk was low. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  17. Radical fashion and radical fashion innovation

    NARCIS (Netherlands)

    Zhang, D.; Benedetto, Di A.C.

    2010-01-01

    This is a study of the related concepts of radical fashion and radical fashion innovation. Radical fashions are defined here as those that may never enter the market at all, and exist primarily on runway shows, in exhibitions and in publicity; by contrast, radical fashion innovations may be very

  18. Determination of Free Radical Scavenging, Antioxidative DNA Damage Activities and Phytochemical Components of Active Fractions from Lansium domesticum Corr. Fruit

    Science.gov (United States)

    Klungsupya, Prapaipat; Suthepakul, Nava; Muangman, Thanchanok; Rerk-Am, Ubon; Thongdon-A, Jeerayu

    2015-01-01

    Lansium domesticum Corr. or “long-kong” is one of the most popular fruits in Thailand. Its peel (skin, SK) and seeds (SD) become waste unless recycled or applied for use. This study was undertaken to determine the bioactivity and phytochemical components of L. domesticum (LD) skin and seed extracts. Following various extraction and fractionation procedures, 12 fractions were obtained. All fractions were tested for antioxidant capacity against O2−• and OH•. It was found that the peel of L. domesticum fruits exhibited higher O2−• and OH• scavenging activity than seeds. High potential antioxidant activity was found in two fractions of 50% ethanol extract of peel followed by ethyl acetate (EA) fractionation (LDSK50-EA) and its aqueous phase (LDSK50-H2O). Therefore, these two active fractions were selected for further studies on their antioxidative activity against DNA damage by hydrogen peroxide (H2O2) in human TK6 cells using comet assay. The comet results revealed DNA-protective activity of both LDSK50-EA and LDSK50-H2O fractions when TK6 human lymphoblast cells were pre-treated at 25, 50, 100, and 200 μg/mL for 24 h prior to H2O2 exposure. The phytochemical analysis illustrated the presence of phenolic substances, mainly scopoletin, rutin, and chlorogenic acid, in these two active fractions. This study generates new information on the biological activity of L. domesticum. It will promote and strengthen the utilization of L. domesticum by-products. PMID:26287238

  19. Determination of Free Radical Scavenging, Antioxidative DNA Damage Activities and Phytochemical Components of Active Fractions from Lansium domesticum Corr. Fruit

    Directory of Open Access Journals (Sweden)

    Prapaipat Klungsupya

    2015-08-01

    Full Text Available Lansium domesticum Corr. or “long-kong” is one of the most popular fruits in Thailand. Its peel (skin, SK and seeds (SD become waste unless recycled or applied for use. This study was undertaken to determine the bioactivity and phytochemical components of L. domesticum (LD skin and seed extracts. Following various extraction and fractionation procedures, 12 fractions were obtained. All fractions were tested for antioxidant capacity against O2−• and OH•. It was found that the peel of L. domesticum fruits exhibited higher O2−• and OH• scavenging activity than seeds. High potential antioxidant activity was found in two fractions of 50% ethanol extract of peel followed by ethyl acetate (EA fractionation (LDSK50-EA and its aqueous phase (LDSK50-H2O. Therefore, these two active fractions were selected for further studies on their antioxidative activity against DNA damage by hydrogen peroxide (H2O2 in human TK6 cells using comet assay. The comet results revealed DNA-protective activity of both LDSK50-EA and LDSK50-H2O fractions when TK6 human lymphoblast cells were pre-treated at 25, 50, 100, and 200 μg/mL for 24 h prior to H2O2 exposure. The phytochemical analysis illustrated the presence of phenolic substances, mainly scopoletin, rutin, and chlorogenic acid, in these two active fractions. This study generates new information on the biological activity of L. domesticum. It will promote and strengthen the utilization of L. domesticum by-products.

  20. A novel heterogeneous system for sulfate radical generation through sulfite activation on a CoFe{sub 2}O{sub 4} nanocatalyst surface

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zizheng [School of Civil Engineering, Wuhan University, Wuhan, 430072 (China); Yang, Shaojie; Yuan, Yanan; Xu, Jing; Zhu, Yifan [Department of Environmental Science, Hubei Key Lab of Biomass Resource Chemistry and Environmental Biotechnology, School of Resources and Environmental Science, Wuhan University, Wuhan, 430079 (China); Li, Jinjun, E-mail: ljj0410@163.com [Department of Environmental Science, Hubei Key Lab of Biomass Resource Chemistry and Environmental Biotechnology, School of Resources and Environmental Science, Wuhan University, Wuhan, 430079 (China); Wu, Feng, E-mail: fengwu@whu.edu.cn [Department of Environmental Science, Hubei Key Lab of Biomass Resource Chemistry and Environmental Biotechnology, School of Resources and Environmental Science, Wuhan University, Wuhan, 430079 (China)

    2017-02-15

    Highlights: • CoFe{sub 2}O{sub 4}−S(IV)−O{sub 2} system is proposed as a new system of sulfate radical based AOPs. • Alkaline pH favors the activation of sulfite on CoFe{sub 2}O{sub 4} surface to produce oxysulfur radicals. • Generation of Co−OH complexes on the surface of CoFe{sub 2}O{sub 4} is the main factor for sulfite activation. • Degradation of organic contaminants by CoFe{sub 2}O{sub 4}−S(IV)−O{sub 2} system were achieved. • Main intermediates and pathways for the degradation of metoprolol were identified. - Abstract: Heterogeneous catalytic activation is important for potential application of new sulfate-radical-based advanced oxidation process using sulfite as source of sulfate radical. We report herein a heterogeneous system for sulfite activation by CoFe{sub 2}O{sub 4} nanocatalyst for metoprolol removal. Factors that influence metoprolol removal were investigated, including pH and initial concentrations of components. The CoFe{sub 2}O{sub 4} nanocatalyst was characterized by X-ray diffractometry (XRD) and transmission electron microscopy (TEM), and the catalytic stability was tested by consecutive runs. Radicals generated in the CoFe{sub 2}O{sub 4}−S(IV)−O{sub 2} system were identified through radical quenching experiments and by electron spin resonance (ESR). The catalytic mechanism was elucidated further by X-ray photoelectron spectroscopy (XPS). The catalytic process was dependent on initial pH, and more than 80% of the metoprolol can be removed at pH 10.0 following the Langmubir-Hinshelwood equation. The generation of Co-OH complexes on the CoFe{sub 2}O{sub 4} surface was crucial for sulfite activation. SO{sub 4}{sup ·−} was verified to be the main oxidative species responsible for metoprolol degradation. Other organic pollutants, such as sulfanilamide, sulfasalazine, 2-nitroaniline, sulfapyridine, aniline, azo dye X-3B and 4-chloroaniline, could also be removed in this CoFe{sub 2}O{sub 4}−S(IV)−O{sub 2} system. The

  1. In situ generation of a hydroxyl radical by nanoporous activated carbon derived from rice husk for environmental applications: kinetic and thermodynamic constants.

    Science.gov (United States)

    Karthikeyan, S; Sekaran, G

    2014-03-07

    The objective of this investigation is to evaluate the hydroxyl radical (˙OH) generation using nanoporous activated carbon (NPAC), derived from rice husk, and dissolved oxygen in water. The in situ production of the ˙OH radical was confirmed through the DMPO spin trapping method in EPR spectroscopy and quantitative determination by a deoxyribose assay procedure. NPAC served as a heterogeneous catalyst to degrade 2-deoxy-d-ribose (a reference compound) using hydroxyl radical generated from dissolved oxygen in water at temperatures in the range 313-373 K and pH 6, with first order rate constants (k = 9.2 × 10(-2) min(-1), k = 1.2 × 10(-1) min(-1), k = 1.3 × 10(-1) min(-1) and k = 1.68 × 10(-1) min(-1)). The thermodynamic constants for the generation of hydroxyl radicals by NPAC and dissolved oxygen in water were ΔG -1.36 kJ mol(-1) at 313 K, ΔH 17.73 kJ mol(-1) and ΔS 61.01 J mol(-1) K(-1).

  2. Chemical constituents and free radical scavenging activity of corn pollen collected from Apis mellifera hives compared to floral corn pollen at Nan, Thailand

    Directory of Open Access Journals (Sweden)

    Chantarudee Atip

    2012-04-01

    Full Text Available Abstract Background Bee pollen is composed of floral pollen mixed with nectar and bee secretion that is collected by foraging honey (Apis sp. and stingless bees. It is rich in nutrients, such as sugars, proteins, lipids, vitamins and flavonoids, and has been ascribed antiproliferative, anti-allergenic, anti-angiogenic and free radical scavenging activities. This research aimed at a preliminary investigation of the chemical constituents and free radical scavenging activity in A. mellifera bee pollen. Methods Bee pollen was directly collected from A. mellifera colonies in Nan province, Thailand, in June, 2010, whilst floral corn (Zea mays L. pollen was collected from the nearby corn fields. The pollen was then sequentially extracted with methanol, dichloromethane (DCM and hexane, and each crude extract was tested for free radical scavenging activity using the DPPH assay, evaluating the percentage scavenging activity and the effective concentration at 50% (EC50. The most active crude fraction from the bee pollen was then further enriched for bioactive components by silica gel 60 quick and adsorption or Sephadex LH-20 size exclusion chromatography. The purity of all fractions in each step was observed by thin layer chromatography and the bioactivity assessed by the DPPH assay. The chemical structures of the most active fractions were analyzed by nuclear magnetic resonance. Results The crude DCM extract of both the bee corn pollen and floral corn pollen provided the highest active free radical scavenging activity of the three solvent extracts, but it was significantly (over 28-fold higher in the bee corn pollen (EC50 = 7.42 ± 0.12 μg/ml, than the floral corn pollen (EC50 = 212 ± 13.6% μg/ml. After fractionation to homogeneity, the phenolic hydroquinone and the flavone 7-O-R-apigenin were found as the minor and major bioactive compounds, respectively. Bee corn pollen contained a reasonably diverse array of nutritional components, including

  3. Chromatographic analysis, anti-proliferative and radical scavenging activity of Pinus wallichina essential oil growing in high altitude areas of Kashmir, India.

    Science.gov (United States)

    Yousuf Dar, Mohd; Shah, Wajaht A; Mubashir, Sofi; Rather, Manzoor A

    2012-10-15

    To evaluate the in vitro anti-proliferative and radical scavenging properties of the essential oil and its fractions and to determine the chemo-type of P. wallichiana essential oil. Pinus wallichiana oil was extracted by hydro-distillation and fractionated by silica gel column chromatography method. The oil and its fractions were analyzed by Gas chromatography, Gas chromatography-mass spectrometry and (13)C NMR. Different concentrations of oil 12.5, 25, 50 and 100μg/ml and single concentration 50μg/ml of its fractions B(1), B(2), A(2), G(2), Uk(13) and I(2) were evaluated for its anti-proliferative activity by in vitro {3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide} assay against human monocyte, lung carcinoma, liver adenocarcinoma, prostate and ovarian carcinoma, while as the radical scavenging activity was evaluated by different in vitro DPPH assays. The analyses indicated the presence of 17 constituents with β-pinene (46.8%) and α-pinene (25.2%) as major constituents. The oil and its fractions showed significant anti-proliferative activity. The radical scavenging activity also showed good results. The oil could be used as a drug to control the diseases like cancer, cirrhosis and arteriosclerosis, caused by reactive oxygen species. Copyright © 2012 Elsevier GmbH. All rights reserved.

  4. Understanding Free Radicals: Isolating Active Thylakoid Membranes and Purifying the Cytochrome b6f Complex for Superoxide Generation Studies

    Directory of Open Access Journals (Sweden)

    Jason Stofleth

    2012-01-01

    Full Text Available All life persists in an environment that is rich in molecular oxygen. The production of oxygen free radicals, or superoxide, is a necessary consequence of the biogenesis of energy in cells. Both mitochondrial and photosynthetic electron transport chains have been found to produce superoxide associated with cell differentiation, proliferation, and cell death, thereby contributing to the effects of aging. Aerobic respiration in mitochondria consumes oxygen, whereas photosynthesis in chloroplasts or cyanobacteria produces oxygen. The increased concentration of molecular oxygen may serve to allow greater availability for the production of superoxide by cytochrome bc complexes in photosynthetic membranes compared to those of mitochondrial membranes. The isolation of well-coupled chloroplasts, containing the cytochrome b6f complex of oxygenic photosynthesis, is a vital initial step in the process of comparing the rate of production of superoxide to those of the homologous cytochrome bc1 complex of aerobic respiration. It is necessary to determine if the isolated chloroplasts have retained their oxygengenerating capability after isolation by an oxygen evolution assay with a Clark-type electrode. A necessary second step, which is the isolation of cytochrome b6f from spinach, has yet to be successfully performed. Oxygen measurements taken from chloroplasts in the presence of the uncoupler, NH4Cl, exhibited a rate of oxygen evolution over three times greater at 344 +/- 18 μmol O2/mg Chlorophyll a/hr than the rate of oxygen evolution without uncoupler at 109 +/- 29 μmol O2/mg Chlorophyll a/hr. These data demonstrate that the technique used to isolate spinach chloroplasts preserves their light-driven electron-transport activity, making them reliable for future superoxide assays.

  5. DPPH radical scavenging activity of a mixture of fatty acids and peptide-containing compounds in a protein hydrolysate of Jatropha curcas seed cake.

    Science.gov (United States)

    Phengnuam, Thanyarat; Goroncy, Alexander K; Rutherfurd, Shane M; Moughan, Paul J; Suntornsuk, Worapot

    2013-12-04

    Jatropha curcas, a tropical plant, has great potential commercial relevance as its seeds have high oil content. The seeds can be processed into high-quality biofuel producing seed cake as a byproduct. The seed cake, however, has not gotten much attention toward its potential usefulness. This work was aimed to determine the antioxidant activity of different fractions of a protein hydrolysate from J. curcas seed cake and to elucidate the molecular structures of the antioxidants. Seed cake was first processed into crude protein isolate and the protein was hydrolyzed by Neutrase. The hydrolysate obtained from 1 h of Neutrase hydrolysis showed the strongest antioxidant activity against DPPH radical (2,2-diphenyl-1-picrylhydrazyl). After a purification series of protein hydrolysate by liquid chromatography, chemicals acting as DPPH radical inhibitors were found to be a mixture of fatty acids, fatty acid derivatives, and a small amount of peptides characterized by mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy.

  6. Synthesis of Amide and Ester Derivatives of Cinnamic Acid and Its Analogs: Evaluation of Their Free Radical Scavenging and Monoamine Oxidase and Cholinesterase Inhibitory Activities.

    Science.gov (United States)

    Takao, Koichi; Toda, Kazuhiro; Saito, Takayuki; Sugita, Yoshiaki

    2017-01-01

    A series of cinnamic acid derivatives, amides (1-12) and esters (13-22), were synthesized, and structure-activity relationships for antioxidant activity, and monoamine oxidases (MAO) A and B, acetylcholinesterase, and butyrylcholinesterase (BChE) inhibitory activities were analyzed. Among the synthesized compounds, compounds 1-10, 12-18, and rosmarinic acid (23), which contained catechol, o-methoxyphenol or 5-hydroxyindole moieties, showed potent 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Compounds 9-11, 15, 17-22 showed potent and selective MAO-B inhibitory activity. Compound 20 was the most potent inhibitor of MAO-B. Compounds 18 and 21 showed moderate BChE inhibitory activity. In addition, compound 18 showed potent antioxidant activity and MAO-B inhibitory activity. In a comparison of the cinnamic acid amides and esters, the amides exhibited more potent DPPH free radical scavenging activity, while the esters showed stronger inhibitory activities against MAO-B and BChE. These results suggested that cinnamic acid derivatives such as compound 18, p-coumaric acid 3,4-dihydroxyphenethyl ester, and compound 20, p-coumaric acid phenethyl ester, may serve as lead compounds for the development of novel MAO-B inhibitors and candidate lead compounds for the prevention or treatment of Alzheimer's disease.

  7. Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L.), J. oxycedrus (L.), J. phoenicea (L.) and Tetraclinis articulata (L.)

    OpenAIRE

    El Jemli, Meryem; Kamal, Rabie; Marmouzi, Ilias; Zerrouki, Asmae; Cherrah, Yahia; Alaoui, Katim

    2016-01-01

    Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) assays. Also the total phenolic ...

  8. Significance of the Centrally Expressed TRP Channel "Painless" in "Drosophila" Courtship Memory

    Science.gov (United States)

    Sakai, Takaomi; Sato, Shoma; Ishimoto, Hiroshi; Kitamoto, Toshihiro

    2013-01-01

    Considerable evidence has demonstrated that transient receptor potential (TRP) channels play vital roles in sensory neurons, mediating responses to various environmental stimuli. In contrast, relatively little is known about how TRP channels exert their effects in the central nervous system to control complex behaviors. This is also true for the…

  9. Chemical Excitation and Inactivation in Photoreceptors of the Fly Mutants trp and nss

    NARCIS (Netherlands)

    Suss, E.; Barash, S.; Stavenga, D.G.; Stieve, H.; Selinger, Z.; Minke, B.

    1989-01-01

    The Drosophila and Lucilia photoreceptor mutants, trp and nss, respond like wild-type flies to a short pulse of intense light or prolonged dim light; however, upon continuous intense illumination, the trp and nss mutants are unable to maintain persistent excitation. This defect manifests itself by a

  10. Nonlinear vs. linear biasing in Trp-cage folding simulations

    Energy Technology Data Exchange (ETDEWEB)

    Spiwok, Vojtěch, E-mail: spiwokv@vscht.cz; Oborský, Pavel; Králová, Blanka [Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technická 3, Prague 6 166 28 (Czech Republic); Pazúriková, Jana [Institute of Computer Science, Masaryk University, Botanická 554/68a, 602 00 Brno (Czech Republic); Křenek, Aleš [Institute of Computer Science, Masaryk University, Botanická 554/68a, 602 00 Brno (Czech Republic); Center CERIT-SC, Masaryk Univerzity, Šumavská 416/15, 602 00 Brno (Czech Republic)

    2015-03-21

    Biased simulations have great potential for the study of slow processes, including protein folding. Atomic motions in molecules are nonlinear, which suggests that simulations with enhanced sampling of collective motions traced by nonlinear dimensionality reduction methods may perform better than linear ones. In this study, we compare an unbiased folding simulation of the Trp-cage miniprotein with metadynamics simulations using both linear (principle component analysis) and nonlinear (Isomap) low dimensional embeddings as collective variables. Folding of the mini-protein was successfully simulated in 200 ns simulation with linear biasing and non-linear motion biasing. The folded state was correctly predicted as the free energy minimum in both simulations. We found that the advantage of linear motion biasing is that it can sample a larger conformational space, whereas the advantage of nonlinear motion biasing lies in slightly better resolution of the resulting free energy surface. In terms of sampling efficiency, both methods are comparable.

  11. Activation of semantic information at the sublexical level during handwriting production: Evidence from inhibition effects of Chinese semantic radicals in the picture-word interference paradigm.

    Science.gov (United States)

    Chen, Xuqian; Liao, Yuanlan; Chen, Xianzhe

    2017-08-01

    Using a non-alphabetic language (e.g., Chinese), the present study tested a novel view that semantic information at the sublexical level should be activated during handwriting production. Over 80% of Chinese characters are phonograms, in which semantic radicals represent category information (e.g., 'chair,' 'peach,' 'orange' are related to plants) while phonetic radicals represent phonetic information (e.g., 'wolf,' 'brightness,' 'male,' are all pronounced /lang/). Under different semantic category conditions at the lexical level (semantically related in Experiment 1; semantically unrelated in Experiment 2), the orthographic relatedness and semantic relatedness of semantic radicals in the picture name and its distractor were manipulated under different SOAs (i.e., stimulus onset asynchrony, the interval between the onset of the picture and the onset of the interference word). Two questions were addressed: (1) Is it possible that semantic information could be activated in the sublexical level conditions? (2) How are semantic and orthographic information dynamically accessed in word production? Results showed that both orthographic and semantic information were activated under the present picture-word interference paradigm, dynamically under different SOAs, which supported our view that discussions on semantic processes in the writing modality should be extended to the sublexical level. The current findings provide possibility for building new orthography-phonology-semantics models in writing. © 2017 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  12. Assessment of Free Radical Scavenging Activity of Dimethylglycine Sodium Salt and Its Role in Providing Protection against Lipopolysaccharide-Induced Oxidative Stress in Mice.

    Science.gov (United States)

    Bai, Kaiwen; Xu, Wen; Zhang, Jingfei; Kou, Tao; Niu, Yu; Wan, Xiaoli; Zhang, Lili; Wang, Chao; Wang, Tian

    2016-01-01

    In the present study, the free radical scavenging activities (against 1,1-diphenyl-2-pierylhydrazy (DPPH), 2,2'-Azinobis-(3-ethylbenzthiazoline-6- sulphonate) (ABTS+), Hydrogen peroxide (H2O2)) of dimethylglycine sodium salt (DMG-Na) were measured and compared with those of Trolox (6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid), a commonly used antioxidant. The radical scavenging activities of DMG-Na were found to be the highest at 40 mg/ml. In Experiment 2, gastric intubation in mice with 12 mg DMG-Na/0.3 ml sterile saline solution significantly increased (P DMG-Na/0.3 ml sterile saline solution, which showed the highest antioxidant capacity, was further studied using a mice model. In Experiment 3, the mice CL (CON+ lipopolysaccharide (LPS)) group showed a significant decrease (P DMG+LPS) group showed a significant decrease (P DMG-Na could protect against the LPS-induced oxidative stress by enhancing the free radical scavenging capacity, and increasing the activity of antioxidant defense system.

  13. Clinical implications of thymidylate synthetase, dihydropyrimidine dehydrogenase and orotate phosphoribosyl transferase activity levels in colorectal carcinoma following radical resection and administration of adjuvant 5-FU chemotherapy

    International Nuclear Information System (INIS)

    Ishikawa, Masashi; Miyauchi, Takayuki; Kashiwagi, Yutaka

    2008-01-01

    A number of studies have investigated whether the activity levels of enzymes involved in 5-fluorouracil (5-FU) metabolism are prognostic factors for survival in patients with colorectal carcinoma. Most reports have examined thymidylate synthetase (TS) and dihydropyrimidine dehydrogenase (DPD) in unresectable or metastatic cases, therefore it is unclear whether the activity of these enzymes is of prognostic value in colorectal cancer patients treated with radical resection and adjuvant chemotherapy with 5-FU. This study examined fresh frozen specimens of colorectal carcinoma from 40 patients who had undergone curative operation and were orally administered adjuvant tegafur/uracil (UFT) chemotherapy. TS, DPD and orotate phosphoribosyl transferase (OPRT) activities were assayed in cancer tissue and adjacent normal tissue and their association with clinicopathological variables was investigated. In addition, the relationships between TS, DPD and OPRT activities and patient survival were examined to determine whether any of these enzymes could be useful prognostic factors. While there was no clear relationship between pathological findings and TS or DPD activity, OPRT activity was significantly lower in tumors with lymph node metastasis than in tumors lacking lymph node metastasis. Postoperative survival was significantly better in the groups with low TS activity and/or high OPRT activity. TS and OPRT activity levels in tumor tissue may be important prognostic factors for survival in Dukes' B and C colorectal carcinoma with radical resection and adjuvant chemotherapy with UFT

  14. Distribution of stable free radicals among amino acids of isolated soy proteins.

    Science.gov (United States)

    Lei, Qingxin; Liebold, Christopher M; Boatright, William L; Shah Jahan, M

    2010-09-01

    Application of deuterium sulfide to powdered isolated soy proteins (ISP) was used to quench stable free radicals and produce a single deuterium label on amino acids where free radicals reside. The deuterium labels rendered increases of isotope ratio for the specific ions of radical-bearing amino acids. Isotope ratio measurements were achieved by gas chromatography/mass spectrometry (GC/MS) analyses after the amino acids were released by acidic hydrolysis and converted to volatile derivatives with propyl chloroformate. The isotope enrichment data showed the stable free radicals were located on Ala, Gly, Leu, Ile, Asx (Asp+Asn), Glx (Glu+Gln), and Trp but not on Val, Pro, Met, Phe, Lys, and His. Due to the low abundance of Ser, Thr, and Cys derivatives and the impossibility to accurately measure their isotope ratios, the radical bearing status for these amino acids remained undetermined even though their derivatives were positively identified from ISP hydrolysates. The relative isotope enrichment for radical-bearing amino acids Ala, Gly, Leu, Ile, Asx (Asp+Asn), Glx (Glu+Gln), and Trp were 8.67%, 2.96%, 2.90%, 3.94%, 6.03%, 3.91%, and 21.48%, respectively. Isotope ratio increase for Tyr was also observed but further investigation revealed such increase was mainly from nonspecific deuterium-hydrogen exchange not free radical quenching. The results obtained from the present study provide important information for a better understanding of the mechanisms of free radical formation and stabilization in "dry" ISP.

  15. The Transient Receptor Potential (TRP) Channel Family in Colletotrichum graminicola: A Molecular and Physiological Analysis.

    Science.gov (United States)

    Lange, Mario; Weihmann, Fabian; Schliebner, Ivo; Horbach, Ralf; Deising, Holger B; Wirsel, Stefan G R; Peiter, Edgar

    2016-01-01

    Calcium (Ca2+) is a universal second messenger in all higher organisms and centrally involved in the launch of responses to environmental stimuli. Ca2+ signals in the cytosol are initiated by the activation of Ca2+ channels in the plasma membrane and/or in endomembranes. Yeast (Saccharomyces cerevisiae) contains a Ca2+-permeable channel of the TRP family, TRPY1, which is localized in the vacuolar membrane and contributes to cytosolic free Ca2+ ([Ca2+]cyt) elevations, for example in response to osmotic upshock. A TRPY1 homologue in the rice blast fungus is known to be important for growth and pathogenicity. To determine the role of the TRP channel family in the maize pathogen Colletotrichum graminicola, proteins homologous to TRPY1 were searched. This identified not one, but four genes in the C. graminicola genome, which had putative orthologs in other fungi, and which we named CgTRPF1 through 4. The topology of the CgTRPF proteins resembled that of TRPY1, albeit with a variable number of transmembrane (TM) domains additional to the six-TM-domain core and a diverse arrangement of putatively Ca2+-binding acidic motifs. All CgTRPF genes were expressed in axenic culture and throughout the infection of maize. Like TRPY1, all TRPF proteins of C. graminicola were localized intracellularly, albeit three of them were found not in large vacuoles, but co-localized in vesicular structures. Deletion strains for the CgTRPF genes were not altered in processes thought to involve Ca2+ release from internal stores, i.e. spore germination, the utilization of complex carbon sources, and the generation of tip-focussed [Ca2+]cyt spikes. Heterologous expression of CgTRPF1 through 4 in a tryp1Δ yeast mutant revealed that none of the channels mediated the release of Ca2+ in response to osmotic upshock. Accordingly, aequorin-based [Ca2+]cyt measurements of C. graminicola showed that in this fungus, osmotic upshock-triggered [Ca2+]cyt elevations were generated entirely by influx of Ca2

  16. The Transient Receptor Potential (TRP Channel Family in Colletotrichum graminicola: A Molecular and Physiological Analysis.

    Directory of Open Access Journals (Sweden)

    Mario Lange

    Full Text Available Calcium (Ca2+ is a universal second messenger in all higher organisms and centrally involved in the launch of responses to environmental stimuli. Ca2+ signals in the cytosol are initiated by the activation of Ca2+ channels in the plasma membrane and/or in endomembranes. Yeast (Saccharomyces cerevisiae contains a Ca2+-permeable channel of the TRP family, TRPY1, which is localized in the vacuolar membrane and contributes to cytosolic free Ca2+ ([Ca2+]cyt elevations, for example in response to osmotic upshock. A TRPY1 homologue in the rice blast fungus is known to be important for growth and pathogenicity. To determine the role of the TRP channel family in the maize pathogen Colletotrichum graminicola, proteins homologous to TRPY1 were searched. This identified not one, but four genes in the C. graminicola genome, which had putative orthologs in other fungi, and which we named CgTRPF1 through 4. The topology of the CgTRPF proteins resembled that of TRPY1, albeit with a variable number of transmembrane (TM domains additional to the six-TM-domain core and a diverse arrangement of putatively Ca2+-binding acidic motifs. All CgTRPF genes were expressed in axenic culture and throughout the infection of maize. Like TRPY1, all TRPF proteins of C. graminicola were localized intracellularly, albeit three of them were found not in large vacuoles, but co-localized in vesicular structures. Deletion strains for the CgTRPF genes were not altered in processes thought to involve Ca2+ release from internal stores, i.e. spore germination, the utilization of complex carbon sources, and the generation of tip-focussed [Ca2+]cyt spikes. Heterologous expression of CgTRPF1 through 4 in a tryp1Δ yeast mutant revealed that none of the channels mediated the release of Ca2+ in response to osmotic upshock. Accordingly, aequorin-based [Ca2+]cyt measurements of C. graminicola showed that in this fungus, osmotic upshock-triggered [Ca2+]cyt elevations were generated entirely by

  17. Formation of hydroxyl radicals contributes to the bactericidal activity of ciprofloxacin against Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jensen, Peter Østrup; Briales, Alejandra; Brochmann, Rikke Prejh

    2014-01-01

    induction of cytotoxic hydroxyl radicals (OH˙) during antibiotic treatment of planktonically grown cells may contribute to action of the commonly used antibiotic ciprofloxacin on P. aeruginosa biofilms. For this purpose, WT PAO1, a catalase deficient ΔkatA and a ciprofloxacin resistant mutant of PAO1 (gyr...

  18. A novel heterogeneous system for sulfate radical generation through sulfite activation on a CoFe2O4 nanocatalyst surface.

    Science.gov (United States)

    Liu, Zizheng; Yang, Shaojie; Yuan, Yanan; Xu, Jing; Zhu, Yifan; Li, Jinjun; Wu, Feng

    2017-02-15

    Heterogeneous catalytic activation is important for potential application of new sulfate-radical-based advanced oxidation process using sulfite as source of sulfate radical. We report herein a heterogeneous system for sulfite activation by CoFe 2 O 4 nanocatalyst for metoprolol removal. Factors that influence metoprolol removal were investigated, including pH and initial concentrations of components. The CoFe 2 O 4 nanocatalyst was characterized by X-ray diffractometry (XRD) and transmission electron microscopy (TEM), and the catalytic stability was tested by consecutive runs. Radicals generated in the CoFe 2 O 4 S(IV)O 2 system were identified through radical quenching experiments and by electron spin resonance (ESR). The catalytic mechanism was elucidated further by X-ray photoelectron spectroscopy (XPS). The catalytic process was dependent on initial pH, and more than 80% of the metoprolol can be removed at pH 10.0 following the Langmubir-Hinshelwood equation. The generation of Co-OH complexes on the CoFe 2 O 4 surface was crucial for sulfite activation. SO 4 - was verified to be the main oxidative species responsible for metoprolol degradation. Other organic pollutants, such as sulfanilamide, sulfasalazine, 2-nitroaniline, sulfapyridine, aniline, azo dye X-3B and 4-chloroaniline, could also be removed in this CoFe 2 O 4 S(IV)O 2 system. The results suggest that the CoFe 2 O 4 S(IV)O 2 system has good application prospects in alkaline organic wastewater treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Assessment of antioxidant activity of cane brown sugars by ABTS and DPPH radical scavenging assays: determination of their polyphenolic and volatile constituents.

    Science.gov (United States)

    Payet, Bertrand; Shum Cheong Sing, Alain; Smadja, Jacqueline

    2005-12-28

    Seven cane brown sugars (four from La Réunion, two from Mauritius, and one from France) were investigated for their polyphenol content and volatile composition in relation to their free radical scavenging capacity determined by ABTS and DPPH assays. The thin layer coated on the sugar crystal was extracted by Soxhlet extractor with dichloromethane. The volatile compounds of brown sugars were studied by GC-MS, and 43 compounds were identified. The total phenolic content of brown sugars was determined according to the Folin-Ciocalteu method. Phenolic compounds were quantified in the brown sugar extracts by LC-UV-ESI-MS. Brown sugar aqueous solutions exhibited weak free radical scavenging activity in the DPPH assay and higher antioxidant activity in the ABTS assay at relatively high concentration. The brown sugar extracts showed interesting free radical scavenging properties despite the low concentration of phenolic and volatile compounds. Sugar is a common foodstuff traditionally used for its sweetening properties, which might be accompanied by antioxidant properties arising from molecules (polyphenols, Maillard products) other than sucrose of the cane brown sugars.

  20. In vitro antioxidant properties, free radicals scavenging activities of extracts and polyphenol composition of a non-timber forest product used as spice: Monodora myristica

    Directory of Open Access Journals (Sweden)

    Bruno Moukette Moukette

    2015-01-01

    Full Text Available BACKGROUND: Excessive production of free radicals causes direct damage to biological molecules such as DNA, proteins, lipids, carbohydrates leading to tumor development and progression. Natural antioxidant molecules from phytochemicals of plant origin may directly inhibit either their production or limit their propagation or destroy them to protect the system. In the present study, Monodora myristica a non-timber forest product consumed in Cameroon as spice was screened for its free radical scavenging properties, antioxidant and enzymes protective activities. Its phenolic compound profile was also realized by HPLC. RESULTS: This study demonstrated that M. myristica has scavenging properties against DPPH',OH',NO', and ABTS'radicals which vary in a dose depending manner. It also showed an antioxidant potential that was comparable with that of Butylated Hydroxytoluene (BHT and vitamin C used as standard. The aqueous ethanol extract of M. myristica barks (AEH; showed a significantly higher content in polyphenolic compounds (21.44 ±0.24 mg caffeic acid/g dried extract and flavonoid (5.69 ± 0.07 quercetin equivalent mg/g of dried weight as compared to the other studied extracts. The HPLC analysis of the barks and leaves revealed the presence of several polyphenols. The acids (3,4-OH-benzoic, caffeic, gallic, O- and P- coumaric, syringic, vanillic, alcohols (tyrosol and OH-tyrosol, theobromine, quercetin, rutin, catechine and apigenin were the identified and quantified polyphenols. All the tested extracts demonstrated a high protective potential on the superoxide dismutase (SOD, catalase and peroxidase activities. CONCLUSION: Finally, the different extracts from M. myristica and specifically the aqueous ethanol extract reveal several properties such as higher free radical scavenging properties, significant antioxidant capacities and protective potential effects on liver enzymes.

  1. DPPH RADICAL SCAVENGING ACTIVITY, TOTAL PHENOLICS AND FLAVONOIDS OF WATER SOLUBLE EXTRACTS DERIVED FROM LEAVES AND FRUIT OF Ficus carica L. AND Ficus parietalis Bl.

    Directory of Open Access Journals (Sweden)

    Oktavia Tri Wahyuni

    2016-08-01

    Full Text Available Ficus carica L and Ficus parietalis Bl. (Moraceae are closely related plants which also known in Indonesia as Figs L. Considering the wide therapeutic value of Figs, this research was aimed to evaluate the DPPH-radical scavenging activity of both plants as well as their total phenolic and flavonoids. Extracts were produced by using boiled water and diluted to gain the desired concentration. Analyses were performed by using UV-vis spectrophotometer. Radical scavenging activity testing was done by using radical of DPPH (2,2-diphenyl-1-pycrylhydrazyl to determine the IC50s. The determination of total phenolic was conducted by using Folin-Ciocalteau method and calculated as Gallic Acid Equivalence (GAE. The total flavonoid was measured by using AlCl3-reagents, and calculated as Rutin Equivalence (RE. Afterwards, the radical scavenging activity was correlated to the total phenolic and flavonoids contents. The results showed that the water soluble extract of F. carica fruit had the best IC50 value of 33.38 mg/mL, followed successively by the F. parietalis fruit (35.69 mg/mL, F. parietalis leaves (44.01 mg/mL and the F. carica leaves (76.38 mg/mL. The highest content of total phenolic was shown by the leaves of F. parietalis (1.46% w/w GAE and the lowest was in the fruit or F. carica (0.36% w/w GAE. The highest flavonoid content was detected in the leaves of F. carica (1.42% w/w RE and the lowest was in the F. parietalis fruit (0.20% w/w RE. Correlation analyses of the IC50 values vs. the total phenolic and the flavonoids contents resulted in a positive slope having R2 values as 0.5362 and 0.9895, respectively. As a conclusion, the total flavonoid content influenced the DPPH radical scavenging activity by 98.95%, while the total phenolic content influence was only 53.62%.

  2. D-TRP(8-γMSH Prevents the Effects of Endotoxin in Rat Skeletal Muscle Cells through TNFα/NF-KB Signalling Pathway.

    Directory of Open Access Journals (Sweden)

    Ana Belén Gómez-SanMiguel

    Full Text Available Sepsis induces anorexia and muscle wasting secondary to an increase in muscle proteolysis. Melanocyte stimulating hormones (MSH is a family of peptides that have potent anti-inflammatory effects. Melanocortin receptor-3 (MC3-R has been reported as the predominant anti-inflammatory receptor for melanocortins. The aim of this work was to analyse whether activation of MC3-R, by administration of its agonist D-Trp(8-γMSH, is able to modify the response of skeletal muscle to inflammation induced by lipopolysaccharide endotoxin (LPS or TNFα. Adult male rats were injected with 250 μg/kg LPS and/or 500 μg/kg D-Trp(8-γMSH 17:00 h and at 8:00 h the following day, and euthanized 4 hours afterwards. D-Trp(8-γMSH decreased LPS-induced anorexia and prevented the stimulatory effect of LPS on hypothalamic IL-1β, COX-2 and CRH as well as on serum ACTH and corticosterone. Serum IGF-I and its expression in liver and gastrocnemius were decreased in rats injected with LPS, but not in those that also received D-Trp(8-γMSH. However, D-Trp(8-γMSH was unable to modify the effect of LPS on IGFBP-3. In the gastrocnemius D-Trp(8-γMSH blocked LPS-induced decrease in pAkt, pmTOR, MHC I and MCH II, as well as the increase in pNF-κB(p65, FoxO1, FoxO3, LC3b, Bnip-3, Gabarap1, atrogin-1, MuRF1 and in LC3a/b lipidation. In L6 myotube cultures, D-Trp(8-γMSH was able to prevent TNFα-induced increase of NF-κB(p65 phosphorylation and decrease of Akt phosphorylation as well as of IGF-I and MHC I expression. These data suggest that MC3-R activation prevents the effect of endotoxin on skeletal wasting by modifying inflammation, corticosterone and IGF-I responses and also by directly acting on muscle cells through the TNFα/NF-κB(p65 pathway.

  3. HPLC-Analysis of Polyphenolic Compounds in Gardenia jasminoides and Determination of Antioxidant Activity by Using Free Radical Scavenging Assays

    OpenAIRE

    Riaz Uddin; Moni Rani Saha; Nusrat Subhan; Hemayet Hossain; Ismet Ara Jahan; Raushanara Akter; Ashraful Alam

    2014-01-01

    Purpose: Gardenia jasminoides is a traditional medicinal plant rich in anti-inflammatory flavonoids and phenolic compounds and used for the treatment of inflammatory diseases and pain. In this present study, antioxidant potential of Gardenia jasminoides leaves extract was evaluated by using various antioxidant assays. Methods: Various antioxidant assays such as 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, reducing power and total antioxidant capacity expressed as equival...

  4. TRP channels in brown and white adipogenesis from human progenitors: new therapeutic targets and the caveats associated with the common antibiotic, streptomycin.

    Science.gov (United States)

    Goralczyk, Anna; van Vijven, Marc; Koch, Mathilde; Badowski, Cedric; Yassin, M Shabeer; Toh, Sue-Anne; Shabbir, Asim; Franco-Obregón, Alfredo; Raghunath, Michael

    2017-08-01

    Transient receptor potential (TRP) channels are polymodal cell sensors responding to diverse stimuli and widely implicated in the developmental programs of numerous tissues. The evidence for an involvement of TRP family members in adipogenesis, however, is scant. We present the first comprehensive expression profile of all known 27 human TRP genes in mesenchymal progenitors cells during white or brown adipogenesis. Using positive trilineage differentiation as an exclusion criterion, TRP polycystic (P)3, and TPR melastatin (M)8 were found to be uniquely adipospecific. Knockdown of TRPP3 repressed the expression of the brown fat signature genes uncoupling protein (UCP)-1 and peroxisome proliferator-activated receptor γ coactivator (PGC)-1α as well as attenuated forskolin-stimulated uncoupled respiration. However, indices of generalized adipogenesis, such as lipid droplet morphology and fatty acid binding protein (FAPB)-4 expression, were not affected, indicating a principal mitochondrial role of TRPP3. Conversely, activating TRPM8 with menthol up-regulated UCP-1 expression and augmented uncoupled respiration predominantly in white adipocytes (browning), whereas streptomycin antagonized TRPM8-mediated calcium entry, downregulated UCP-1 expression, and mitigated uncoupled respiration; menthol was less capable of augmenting uncoupled respiration (thermogenesis) in brown adipocytes. TRPP3 and TRPM8 hence appear to be involved in the priming of mitochondria to perform uncoupled respiration downstream of adenylate cyclase. Our results also underscore the developmental caveats of using antibiotics in adipogenic studies.-Goralczyk, A., van Vijven, M., Koch, M., Badowski, C., Yassin, M. S., Toh, S.-A., Shabbir, A., Franco-Obregón, A., Raghunath, M. TRP channels in brown and white adipogenesis from human progenitors: new therapeutic targets and the caveats associated with the common antibiotic, streptomycin. © FASEB.

  5. Application of amphipols for structure-functional analysis of TRP channels.

    Science.gov (United States)

    Huynh, Kevin W; Cohen, Matthew R; Moiseenkova-Bell, Vera Y

    2014-10-01

    Amphipathic polymers (amphipols), such as A8-35 and SApol, are a new tool for stabilizing integral membrane proteins in detergent-free conditions for structural and functional studies. Transient receptor potential (TRP) ion channels function as tetrameric protein complexes in a diverse range of cellular processes including sensory transduction. Mammalian TRP channels share ~20 % sequence similarity and are categorized into six subfamilies: TRPC (canonical), TRPV (vanilloid), TRPA (ankyrin), TRPM (melastatin), TRPP (polycystin), and TRPML (mucolipin). Due to the inherent difficulties in purifying eukaryotic membrane proteins, structural studies of TRP channels have been limited. Recently, A8-35 was essential in resolving the molecular architecture of the nociceptor TRPA1 and led to the determination of a high-resolution structure of the thermosensitive TRPV1 channel by cryo-EM. Newly developed maltose-neopentyl glycol (MNG) detergents have also proven to be useful in stabilizing TRP channels for structural analysis. In this review, we will discuss the impacts of amphipols and MNG detergents on structural studies of TRP channels by cryo-EM. We will compare how A8-35 and MNG detergents interact with the hydrophobic transmembrane domains of TRP channels. In addition, we will discuss what these cryo-EM studies reveal on the importance of screening different types of surfactants toward determining high-resolution structures of TRP channels.

  6. Is active surveillance a safe alternative in the management of localized prostate cancer? Pathological features of radical prostatectomy specimens in potential candidates for active surveillance

    Directory of Open Access Journals (Sweden)

    Zambrano Norman

    2014-04-01

    Full Text Available Introduction and objectiveActive surveillance (AS has become an accepted alternative for patients with low risk prostate cancer. The purpose of AS is to defer definitive therapy in these patients to avoid treatment-related complications. Our aim was to determine the pathological features of the surgical specimen from potential AS candidates that underwent radical prostatectomy (RP.Materials and MethodsWe retrospectively reviewed a group of patients submitted to RP who met criteria for AS: Gleason score (GS ≤ 3+3 = 6, PSA ≤ 10ng/mL, T1c - T2a, 6 in the RPS (GS 7 n = 49; GS 8 n = 3. Extracapsular extension, seminal vesicle and lymph node involvement was found in 6.1%, 3.1% and 1.2% of the specimens, respectively.ConclusionIn this study a significant proportion of potential candidates for AS showed features of aggressive and/or high-risk tumors in the RPS. Therefore, before considering a patient for an AS protocol, a proper and strict selection must be performed, and informed consent is crucial for these patients.

  7. Mutational analysis of amino acid residues involved in catalytic activity of a family 18 chitinase from tulip bulbs.

    Science.gov (United States)

    Suzukawa, Keisuke; Yamagami, Takeshi; Ohnuma, Takayuki; Hirakawa, Hideki; Kuhara, Satoru; Aso, Yoichi; Ishiguro, Masatsune

    2003-02-01

    We expressed chitinase-1 (TBC-1) from tulip bulbs (Tulipa bakeri) in E. coli cells and used site-directed mutagenesis to identify amino acid residues essential for catalytic activity. Mutations at Glu-125 and Trp-251 completely abolished enzyme activity, and activity decreased with mutations at Asp-123 and Trp-172 when glycolchitin was the substrate. Activity changed with the mutations of Trp-251 to one of several amino acids with side-chains of little hydrophobicity, suggesting that hydrophobic interaction of Trp-251 is important for the activity. Molecular dynamics (MD) simulation analysis with hevamine as the model compound showed that the distance between Asp-123 and Glu-125 was extended by mutation of Trp-251. Kinetic studies of Trp-251-mutated chitinases confirmed these various phenomena. The results suggested that Glu-125 and Trp-251 are essential for enzyme activity and that Trp-251 had a direct role in ligand binding.

  8. UV-induced tandem double mutations in the trpA gene of E. coli

    International Nuclear Information System (INIS)

    Piechocki, R.; Langhammer, R.

    1980-01-01

    The ultraviolet light induction of tandem double mutations in a reverse mutation system was shown using trpA mutants which are characterized by the codon sequences GAA and AAG in codon position 211. Among 597 Trp + independent revertants of the trpA (AAG211) strain 3 full revertants were detected arising from UV-induced tandem double base exchanges. In the codon unit 211 full revertants due to single base exchanges are at least 20 times as frequent as full revertants due to tandem double base exchanges. (author)

  9. In Vitro Antioxidant-Activity Evaluation of Gallic-Acid-Grafted Chitosan Conjugate Synthesized by Free-Radical-Induced Grafting Method.

    Science.gov (United States)

    Hu, Qiaobin; Wang, Taoran; Zhou, Mingyong; Xue, Jingyi; Luo, Yangchao

    2016-07-27

    The major objective of this work was to develop a green and facile process to prepare gallic acid-chitosan conjugate and comprehensively evaluate the physicochemical properties and biological activities of an as-prepared water-soluble chitosan derivative. A free-radical-induced grafting approach using an ascorbic acid-hydrogen peroxide redox pair was adopted. The obtained conjugate was characterized by Fourier transform infrared spectroscopy, UV-vis, X-ray diffraction, and pKa analysis. The antioxidant activities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6)-sulphonic acid (ABTS), reducing power, and oxygen-radical antioxidant-capacity assays. The results showed that the mass ratio of gallic acid to chitosan played a vital role in determining the grafting degree and ζ potential of the conjugates, with the ratio of 0.5:1 being the optimal ratio that resulted in the highest grafting degree. The antioxidant assays demonstrated that conjugation significantly improved the antioxidant activities, being dramatically higher than that of free chitosan. It was notable that the DPPH- and ABTS-scavenging activities of conjugate at 0.4 mg/mL reached the same level as the free gallic acid at the equivalent concentration. Our study demonstrated a green and facile synthesis approach to preparing a novel water-soluble chitosan derivative that may have promising potentials in the food industry.

  10. Oxidation of the tryptophan 32 residue of human superoxide dismutase 1 caused by its bicarbonate-dependent peroxidase activity triggers the non-amyloid aggregation of the enzyme.

    Science.gov (United States)

    Coelho, Fernando R; Iqbal, Asif; Linares, Edlaine; Silva, Daniel F; Lima, Filipe S; Cuccovia, Iolanda M; Augusto, Ohara

    2014-10-31

    The role of oxidative post-translational modifications of human superoxide dismutase 1 (hSOD1) in the amyotrophic lateral sclerosis (ALS) pathology is an attractive hypothesis to explore based on several lines of evidence. Among them, the remarkable stability of hSOD1(WT) and several of its ALS-associated mutants suggests that hSOD1 oxidation may precede its conversion to the unfolded and aggregated forms found in ALS patients. The bicarbonate-dependent peroxidase activity of hSOD1 causes oxidation of its own solvent-exposed Trp(32) residue. The resulting products are apparently different from those produced in the absence of bicarbonate and are most likely specific for simian SOD1s, which contain the Trp(32) residue. The aims of this work were to examine whether the bicarbonate-dependent peroxidase activity of hSOD1 (hSOD1(WT) and hSOD1(G93A) mutant) triggers aggregation of the enzyme and to comprehend the role of the Trp(32) residue in the process. The results showed that Trp(32) residues of both enzymes are oxidized to a similar extent to hSOD1-derived tryptophanyl radicals. These radicals decayed to hSOD1-N-formylkynurenine and hSOD1-kynurenine or to a hSOD1 covalent dimer cross-linked by a ditryptophan bond, causing hSOD1 unfolding, oligomerization, and non-amyloid aggregation. The latter process was inhibited by tempol, which recombines with the hSOD1-derived tryptophanyl radical, and did not occur in the absence of bicarbonate or with enzymes that lack the Trp(32) residue (bovine SOD1 and hSOD1(W32F) mutant). The results support a role for the oxidation products of the hSOD1-Trp(32) residue, particularly the covalent dimer, in triggering the non-amyloid aggregation of hSOD1. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. The effect of different conventional methods of extraction on Marantodes pumila var. pumila leaves in relation to free radical scavenging activity

    Science.gov (United States)

    Hamid, Noor Huda Abd; Latip, Jalifah; Markom, Masturah

    2018-04-01

    Marantodes pumila is one of the important herbs used in traditional medicine. However, there is no report on the optimum method for the preparation of M. pumila extract enriched with bioactive compounds. Therefore, this study aim to establish the suitable method in the preparation of M. pumila extracts enriched with antioxidative compounds. Different conventional extraction methods such as maceration, reflux and Soxhlet in solvents of different polarities i.e. ethanol, 50 % aqueous ethanol and water were employed to prepare extracts. Constituents of each extract were profiled using RP-HPLC followed by the free radical scavenging assay using 2,2 diphenyl-1-picrylhydrazyl (DPPH) to determine the antioxidant activity. Among all extraction methods, maceration in 50 % aqueous ethanol gave the highest total percentage yield (22.41 %) while all extraction methods were able to extract the marker compounds, gallic acid (GA) and methyl gallate (MGA). The free radical scavenging activity of extracts varied from IC50 11.93 µg/mL (50 % aqueous ethanol via reflux) to 64.15 µg/mL (water via maceration). All extracts showed better scavenging activity as compared to synthetic antioxidant, BHT. The variation in the IC50 values is expected due to the presence of different types and/or concentration of bioactive compounds in each extract. This study may provide a preliminary insight for the preparation of standardized extracts of M. pumila enriched with bioactive compounds.

  12. Radical Change by Entrepreneurial Design

    National Research Council Canada - National Science Library

    Roberts, Nancy C

    1998-01-01

    .... How radical change in public policy has occurred in the past is then documented. We find examples of radical change by chance, radical change by consensus, radical change by learning, and radical change by entrepreneurial design...

  13. Immunolocalization and distribution of functional temperature-sensitive TRP channels in salivary glands.

    Science.gov (United States)

    Sobhan, Ubaidus; Sato, Masaki; Shinomiya, Takashi; Okubo, Migiwa; Tsumura, Maki; Muramatsu, Takashi; Kawaguchi, Mitsuru; Tazaki, Masakazu; Shibukawa, Yoshiyuki

    2013-11-01

    Transient receptor potential (TRP) cation channels are unique cellular sensors involved in multiple cellular functions. Their role in salivary secretion remains to be elucidated. The expression and localization of temperature-sensitive TRP channels in salivary (submandibular, sublingual and parotid) glands were analyzed by immunohistochemistry and quantitative real-time reverse transcription plus the polymerase chain reaction (RT-PCR). The effects of various TRP channel agonists on carbachol (CCh)-induced salivary secretion in the submandibular gland and on the intracellular Ca(2+) concentration ([Ca(2+)]i) in a submandibular epithelial cell line were also investigated. Immunohistochemistry revealed the expression of TRP-melastatin subfamily member 8 (TRPM8) and TRP-ankyrin subfamily member 1 (TRPA1) in myoepithelial, acinar and ductal cells in the sublingual, submandibular and parotid glands. In addition, TRP-vanilloid subfamily member 1 (TRPV1), TRPV3 and TRPV4 were also expressed in myoepithelial, acinar and ductal cells in all three types of gland. Quantitative real-time RT-PCR results demonstrated the mRNA expression of TRPV1, TRPV3, TRPV4, TRPM8 and TRPA1 in acinar and ductal cells in these salivary glands. Perfusion of the entire submandibular gland with the TRPV1 agonist capsaicin (1 μM) via the submandibular artery significantly increased CCh-induced salivation, whereas perfusion with TRPM8 and TRPA1 agonists (0.5 μM WS12 and 100 μM allyl isothiocyanate) decreased it. Application of agonists for each of the thermosensitive TRP channels increased [Ca(2+)]i in a submandibular epithelial cell line. These results indicate that temperature-sensitive TRP channels are localized and distributed in acinar, ductal and myoepithelial cells in salivary glands and that they play a functional role in the regulation and/or modulation of salivary secretion.

  14. Flavonoids from Agrimonia pilosa Ledeb: Free Radical Scavenging and DNA Oxidative Damage Protection Activities and Analysis of Bioactivity-Structure Relationship Based on Molecular and Electronic Structures.

    Science.gov (United States)

    Zhu, Liancai; Chen, Jinqiu; Tan, Jun; Liu, Xi; Wang, Bochu

    2017-02-26

    To clarify the substantial basis of the excellent antioxidant capacity of Agrimonia pilosa Ledeb. Fourteen flavonoids were isolated and identified from Agrimonia pilosa Ledeb, seven of which have notable DPPH radical scavenging activities, i.e., catechin, luteolin, quercetin, quercitrin, hyperoside, rutin, luteolin-7- O -β-glucoside with IC 50 values of 5.06, 7.29, 4.36, 7.12, 6.34, 6.36 and 8.12 µM, respectively. The DNA nicking assay showed that five flavonoids from Agrimonia pilosa Ledeb-taxifolin, catechin, hyperoside, quercitrin and rutin-have good protective activity against DNA oxidative damage. Further, we analyzed the bioactivity-structure relationship of these 14 flavonoids by applying quantum theory. According to their O-H bond dissociation enthalpy (BDE), C ring's spin density and stable molecular structure, the relationship between their structures and radical scavenging capacities was evaluated and clarified. We found that among flavonoid aglycones from Agrimonia pilosa Ledeb, the O-H BDE of quercetin is lowest with the values of 69.02 and the O-H BDE of apigenin is highest with the values of 79.77. It is interesting that the O-H BDE value of isovitexin (78.55) with glycoside at C-6 position is lower than that of its aglycone (79.77) and vitexin (99.20) with glycoside at C-8 position. Further analysis indicated that the glycosidation of flavonoids at C-6 in the A-ring makes a more uniform distribution of spin density and improves the stability of free radicals leading to the increase in antioxidant capacity. Flavonoids with good antioxidant capacity might contribute to the pharmacological effects of Agrimonia pilosa Ledeb.

  15. Flavonoids from Agrimonia pilosa Ledeb: Free Radical Scavenging and DNA Oxidative Damage Protection Activities and Analysis of Bioactivity-Structure Relationship Based on Molecular and Electronic Structures

    Directory of Open Access Journals (Sweden)

    Liancai Zhu

    2017-02-01

    Full Text Available To clarify the substantial basis of the excellent antioxidant capacity of Agrimonia pilosa Ledeb. Fourteen flavonoids were isolated and identified from Agrimonia pilosa Ledeb, seven of which have notable DPPH radical scavenging activities, i.e., catechin, luteolin, quercetin, quercitrin, hyperoside, rutin, luteolin-7-O-β-glucoside with IC50 values of 5.06, 7.29, 4.36, 7.12, 6.34, 6.36 and 8.12 µM, respectively. The DNA nicking assay showed that five flavonoids from Agrimonia pilosa Ledeb—taxifolin, catechin, hyperoside, quercitrin and rutin—have good protective activity against DNA oxidative damage. Further, we analyzed the bioactivity-structure relationship of these 14 flavonoids by applying quantum theory. According to their O-H bond dissociation enthalpy (BDE, C ring’s spin density and stable molecular structure, the relationship between their structures and radical scavenging capacities was evaluated and clarified. We found that among flavonoid aglycones from Agrimonia pilosa Ledeb, the O-H BDE of quercetin is lowest with the values of 69.02 and the O-H BDE of apigenin is highest with the values of 79.77. It is interesting that the O-H BDE value of isovitexin (78.55 with glycoside at C-6 position is lower than that of its aglycone (79.77 and vitexin (99.20 with glycoside at C-8 position. Further analysis indicated that the glycosidation of flavonoids at C-6 in the A-ring makes a more uniform distribution of spin density and improves the stability of free radicals leading to the increase in antioxidant capacity. Flavonoids with good antioxidant capacity might contribute to the pharmacological effects of Agrimonia pilosa Ledeb.

  16. Free radical scavenging activity and neuroprotective potentials of D138, one Cu(II)/Zn(II) Schiff-base complex derived from N,N'-bis(2-hydroxynaphthylmethylidene)-1,3-propanediamine.

    Science.gov (United States)

    Wang, Che; Cai, Zheng-Xu; You, Zhong-Lu; Guo, Hui-Shu; Shang, De-Jing; Wang, Xiao-Ling; Zhang, Liang; Ma, Li-Jie; Tan, Jun; Le, Wei-Dong; Li, Song

    2014-09-01

    There is increasing evidence that free radicals play an important role in neuronal damages induced by diabetes mellitus or cerebral ischemia insults. Antioxidants with free radical scavenging activities have been shown to be beneficial and neuroprotective for these pathological conditions. Here, we report free radical scavenging activity and neuroprotective potential of D138, one copper(II)/zinc(II) Schiff-base complex derived from N,N'-2(2-hydroxynaphthylmethylidene)-1,3-propanediamine. The data from three in vitro assays, 2,2-diphenyl-1-picrylhydrazyl assay, nitro blue tetrazolium assay and hydroxyl radical scavenging assay, indicated that D138 presented a potent free radical scavenging activity. The neuroprotective and antioxidative effects of D138 were further evaluated in vivo using bilateral common carotid artery occlusion (BCCAO) mouse model and streptozotocin (STZ) diabetic mouse model. Our results indicated that treatment of D138 significantly ameliorated the hippocampal neuronal damage and the oxidative stress levels in these animal models. Moreover, D138 also reversed the behavioral deficiencies induced by BCCAO or STZ, as assessed by Y-maze test and fear conditioning test. In conclusion, all these findings support that D138 exerts free radical scavenging and neuroprotective activities and has the potentials to be a potent therapeutic candidate for brain oxidative damage induced by cerebral ischemia or diabetes mellitus.

  17. Antioxidant activities and radical scavenging activities of flavonoids studied by the electrochemical methods and ESR technique based on the novel paramagnetic properties of poly(aniline-co-5-aminosalicylic acid)

    International Nuclear Information System (INIS)

    Yang, Yifei; Mu, Shaolin

    2013-01-01

    Graphical abstract: ESR spectra of the PAASA/RGO/graphite electrodes: (1) in the buffer solution consisting of 0.20 M phosphate and methanol (80: 20, v/v), (2) in the buffer solutions containing 150 μM of (+)-catechin. -- Abstract: Four kinds of flavonoid, viz. flavanone naringenin, Flavone apigenin, flavonol kaempferol, and flavanol (+)-catechin, are used to investigate their antioxidant and radical scavenging activitis in the water-methanol solution of pH 6.3, using the electrochemical methods and electron spin resonance (ESR) technique. Poly(aniline-co-5-aminosalicylic acid) (PAASA) is first used as a radical source that was polymerized on a reduced graphene oxide (RGO)/glassy carbon (GC) disk or on the RGO/graphite fiber electrode. The assessment of the antioxidant activities is performed using both cyclic voltammetry and the open circuit potential measurement. On the basis of results from both electrochemical mathods, the order of the antioxidant actitvities of flavonoids is as follows: (+)-catechin > kaempferol > apigenin > naringenin However, the difference in the antioxidant activities between naringenin and apigenin is very small. On the basis of the ESR signal intensities of PAASA, the order of the radical scavenging activities of flavonoids is in good agreement with that of the above antioxdant activities.Three oxidation peaks on the cyclic voltammograms of (+)-catechin are first detected, which gives us a deep insight into the oxidation mechanism of (+)-catechin

  18. Size-dependent effects of tungsten carbide-cobalt particles on oxygen radical production and activation of cell signaling pathways in murine epidermal cells

    International Nuclear Information System (INIS)

    Ding, M.; Kisin, E.R.; Zhao, J.; Bowman, L.; Lu, Y.; Jiang, B.; Leonard, S.; Vallyathan, V.; Castranova, V.; Murray, A.R.; Fadeel, B.; Shvedova, A.A.

    2009-01-01

    Hard metal or cemented carbide consists of a mixture of tungsten carbide (WC) (85%) and metallic cobalt (Co) (5-15%). WC-Co is considered to be potentially carcinogenic to humans. However, no comparison of the adverse effects of nano-sized WC-Co particles is available to date. In the present study, we compared the ability of nano- and fine-sized WC-Co particles to form free radicals and propensity to activate the transcription factors, AP-1 and NF-κB, along with stimulation of mitogen-activated protein kinase (MAPK) signaling pathways in a mouse epidermal cell line (JB6 P + ). Our results demonstrated that nano-WC-Co generated a higher level of hydroxyl radicals, induced greater oxidative stress, as evidenced by a decrease of GSH levels, and caused faster JB6 P + cell growth/proliferation than observed after exposure of cells to fine WC-Co. In addition, nano-WC-Co activated AP-1 and NF-κB more efficiently in JB6 +/+ cells as compared to fine WC-Co. Experiments using AP-1-luciferase reporter transgenic mice confirmed the activation of AP-1 by nano-WC-Co. Nano- and fine-sized WC-Co particles also stimulated MAPKs, including ERKs, p38, and JNKs with significantly higher potency of nano-WC-Co. Finally, co-incubation of the JB6 +/+ cells with N-acetyl-cysteine decreased AP-1 activation and phosphorylation of ERKs, p38 kinase, and JNKs, thus suggesting that oxidative stress is involved in WC-Co-induced toxicity and AP-1 activation.

  19. Comparison of epoxide and free-radical mechanisms for activation of benzo[a]pyrene by Sprague-Dawley rat liver microsomes

    International Nuclear Information System (INIS)

    Selkirk, J.K.

    1980-01-01

    Coincubation of [6- 3 H]benzo[a]pyrene ([6- 3 H]BP) and [ 14 C]BP with SD rat liver microsomes produced metabolic profiles that showed that the C-6 of BP was not affected by formation of 4,5-dihydro-4,5-dihydroxy-BP, 7,8-dihydro-7,8-dihydroxy-BP, and 9,10-dihydro-9,10-dihydroxy-BP nor the 3- and 9-phenols of BP. Complete retention of tritium at C-6, except in the three quinones, confirmed the radical-cation model for formation of the 6-oxo-radical followed by oxidation to quinone. Epoxide formation at the carcinogenically active regions of BP appeared to biochemically isolate from 6-position activation and suggested that the microsomal epoxide pathway is unrelated to the radicalcation scheme. These molar ratios derived from double-label experiments reinforced the current literature that indicates the epoxide mechanism as the major pathway toward carcinogenic forms of BP

  20. Efficient radical cation stabilization of PANI-ZnO and PANI-ZnO-GO composites and its optical activity

    Energy Technology Data Exchange (ETDEWEB)

    Mathavan, T., E-mail: tjmathavan@gmail.com; Divya, A.; Benial, A. Milton Franklin [PG & Research Department of Physics, N.M.S.S.Vellaichamy Nadar College, Madurai-625 019 (India); Archana, J. [Research Institute of Engineering, Shizuoka University (Japan); Ramasubbu, A. [PG & Research Department of Chemistry, Govt. Arts College, Coimbatore (India); Jothirajan, M. A. [Research Department of Physics, Arul Anandar College, Karumathur, Madurai-625 514 (India)

    2016-05-23

    Polyaniline (PANI) and its composites PANI-ZnO (Zinc oxide) and PANI-ZnO-GO (Graphene oxide) were successfully constructed. These materials were characterized by electron spin resonance (ESR) technique and ultraviolet visible spectrometry. The parameters such as line width, g-factor and spin concentration were deduced from ESR spectra, from the results the radical cation stabilization of PANI, PANI-ZnO and PANI-ZnO-GO composites were compared by the polaron and bipolaron formation. The absorption features obtained in the UV absorption spectra reveal the band gap of these modified PANI composites and also predicted the information of increasing and decreasing features of signal intensity and spin concentration.

  1. Efficient radical cation stabilization of PANI-ZnO and PANI-ZnO-GO composites and its optical activity

    International Nuclear Information System (INIS)

    Mathavan, T.; Divya, A.; Benial, A. Milton Franklin; Archana, J.; Ramasubbu, A.; Jothirajan, M. A.

    2016-01-01

    Polyaniline (PANI) and its composites PANI-ZnO (Zinc oxide) and PANI-ZnO-GO (Graphene oxide) were successfully constructed. These materials were characterized by electron spin resonance (ESR) technique and ultraviolet visible spectrometry. The parameters such as line width, g-factor and spin concentration were deduced from ESR spectra, from the results the radical cation stabilization of PANI, PANI-ZnO and PANI-ZnO-GO composites were compared by the polaron and bipolaron formation. The absorption features obtained in the UV absorption spectra reveal the band gap of these modified PANI composites and also predicted the information of increasing and decreasing features of signal intensity and spin concentration.

  2. DPPH Radical Scavenging and Postprandial Hyperglycemia Inhibition Activities and Flavonoid Composition Analysis of Hawk Tea by UPLC-DAD and UPLC-Q/TOF MSE.

    Science.gov (United States)

    Xiao, Xuan; Xu, Lijia; Hu, Huagang; Yang, Yinjun; Zhang, Xinyao; Peng, Yong; Xiao, Peigen

    2017-10-13

    Hawk tea ( Litsea coreana Lévl. var. Lanuginosa (Migo) Yen C. Yang & P.H. Huang), a very popular herbal tea material, has attracted more and more attention due to its high antioxidant properties and possible therapeutic effect on type II diabetes mellitus. The raw materials of Hawk tea are usually divided into three kinds: bud tea (BT), primary leaf tea (PLT) and mature leaf tea (MLT). In this study, the DPPH radical scavenging activity and the antimicrobial properties of these three kinds of Hawk tea from different regions were comparatively investigated, and a ultra-high performance liquid chromatographic coupled with a photodiode array detector (UPLC-DAD) method was employed for comparison of the three major flavonoid constituents, including hyperoside, isoquercitrin and astragalin, in different samples of Hawk tea. At the same time, the effect of methanol extract (ME) of PLT on the mouse postprandial blood glucose and the effect of ME and its different fractions (petroleum ether fraction (PE), ethyl acetate fraction (EA), n -butanol fraction ( n -BuOH), and water fraction (WF)) on the activity of α-glucosidase were studied. The results showed that Hawk BT and Hawk PLT possessed the higher radicals scavenging activity than Hawk MLT, while the antibacterial activity against P. vulgaris of PLT and MLT was higher than Hawk BT. The contents of the three major flavonoid constituents in samples of Hawk PLT are higher than Hawk BT and Hawk MLT. The mouse postprandial blood glucose levels of the middle dose (0.5 g/kg) group and the high dose (1 g/kg) group with oral administration of the ME of PLT were significantly lower than the control group. What's more, the inhibitory effect of ME of PLT and its EA and n -BuOH fractions on α-glucosidase was significantly higher than that of acarbose. Rapid ultra-high performance liquid chromatography/quadrupole time-of-flight-mass spectrometry (UPLC-ESI-QTOF-MS) was used to identify the flavonoids in Hawk PLT, and a total of 20

  3. DPPH Radical Scavenging and Postprandial Hyperglycemia Inhibition Activities and Flavonoid Composition Analysis of Hawk Tea by UPLC-DAD and UPLC-Q/TOF MSE

    Directory of Open Access Journals (Sweden)

    Xuan Xiao

    2017-10-01

    Full Text Available Hawk tea (Litsea coreana Lévl. var. Lanuginosa (Migo Yen C. Yang & P.H. Huang, a very popular herbal tea material, has attracted more and more attention due to its high antioxidant properties and possible therapeutic effect on type II diabetes mellitus. The raw materials of Hawk tea are usually divided into three kinds: bud tea (BT, primary leaf tea (PLT and mature leaf tea (MLT. In this study, the DPPH radical scavenging activity and the antimicrobial properties of these three kinds of Hawk tea from different regions were comparatively investigated, and a ultra-high performance liquid chromatographic coupled with a photodiode array detector (UPLC-DAD method was employed for comparison of the three major flavonoid constituents, including hyperoside, isoquercitrin and astragalin, in different samples of Hawk tea. At the same time, the effect of methanol extract (ME of PLT on the mouse postprandial blood glucose and the effect of ME and its different fractions (petroleum ether fraction (PE, ethyl acetate fraction (EA, n-butanol fraction (n-BuOH, and water fraction (WF on the activity of α-glucosidase were studied. The results showed that Hawk BT and Hawk PLT possessed the higher radicals scavenging activity than Hawk MLT, while the antibacterial activity against P. vulgaris of PLT and MLT was higher than Hawk BT. The contents of the three major flavonoid constituents in samples of Hawk PLT are higher than Hawk BT and Hawk MLT. The mouse postprandial blood glucose levels of the middle dose (0.5 g/kg group and the high dose (1 g/kg group with oral administration of the ME of PLT were significantly lower than the control group. What’s more, the inhibitory effect of ME of PLT and its EA and n-BuOH fractions on α-glucosidase was significantly higher than that of acarbose. Rapid ultra-high performance liquid chromatography/quadrupole time-of-flight-mass spectrometry (UPLC-ESI-QTOF-MS was used to identify the flavonoids in Hawk PLT, and a total of

  4. A Novel Trp-rich Model Antimicrobial Peptoid with Increased Protease Stability

    International Nuclear Information System (INIS)

    Bang, Jeong Kyu; Nan, Yong Hai; Lee, Eun Kyu; Shin, Song Yub

    2010-01-01

    In order to increase protease stability of a novel Trp-rich model antimicrobial peptide, K 6 L 2 W 3 (KLWKKWKKWLKNH 2 ) and investigate the effect of L-amino acid to peptoid residue conversion on biological functions, we synthesized its antimicrobial peptoid, k 6 l 2 w 3 . Peptoid k 6 l 2 w 3 had similar bacterial selectivity compared to peptide K 6 L 2 W 3 . The bactericidal rate of k 6 l 2 w 3 was somewhat slower than that of K 6 L 2 W 3 . Peptoid k 6 l 2 w 3 exhibited very little dye leakage from bacterial outer-membrane mimicking PE/PG liposomes, as observed in K 6 L 2 W 3 , indicating that the major target site of K 6 L 2 W 3 and k 6 l 2 w 3 may be not the cell membrane but the cytoplasm of bacteria. Trypsin treatment of K 6 L 2 W 3 completely abolished antimicrobial activities against Escherichia coli and Staphylococcus aureus. In contrast, the antimicrobial activity of k 6 l 2 w 3 was completely preserved after trypsin treatment. Taken together, our results suggested that antimicrobial peptoid k 6 l 2 w 3 can potentially serves as a promising therapeutic agent for the treatment of microbial infection

  5. A radical approach to radical innovation

    NARCIS (Netherlands)

    D. Deichmann (Dirk); J.C.M. van den Ende (Jan)

    2014-01-01

    textabstractInnovation pays. Amazon, Apple, Facebook, Google – nearly every one of today’s most successful companies has a talent for developing radical new ideas. But how best to encourage radical initiative taking from employees, and does their previous success or failure at it play a role?

  6. Binding of Gallic Acid and Epigallocatechin Gallate to Heat-Unfolded Whey Proteins at Neutral pH Alters Radical Scavenging Activity of in Vitro Protein Digests.

    Science.gov (United States)

    Cao, Yanyun; Xiong, Youling L

    2017-09-27

    Preheated (80 °C for 9 min) whey protein isolate (HWPI) was reacted with 20, 120, and 240 μmol/g (protein basis) gallic acid (GA) or epigallocatechin gallate (EGCG) at neutral pH and 25 °C. Isothermal titration calorimetry and fluorometry showed a similar trend that GA binding to HWPI was moderate but weaker than EGCG binding. However, the shift of maximal fluorescence emission wavelength in opposite directions in response to GA (blue) and EGCG (red) suggests discrepant binding patterns. Electrophoresis results showed that EGCG induced formation of HWPI complexes while GA only had a marginal effect. Both free and phenolic-bound HWPI exhibited mild antiradical activity. However, when subjected to in vitro digestion, synergistic radical-scavenging activity was produced between the phenolics and peptides with the highest synergism being observed on 120 μmol/g phenolics.

  7. HPLC, NMR and MALDI-TOF MS analysis of condensed tannins from Lithocarpus glaber leaves with potent free radical scavenging activity.

    Science.gov (United States)

    Zhang, Liang Liang; Lin, Yi Ming

    2008-12-04

    Using acid-catalyzed degradation in the presence of cysteamine, the condensed tannins from Lithocarpus glaber leaves were characterized, following thiolysis, by means of reversed-phase HPLC, 13C-NMR and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) analyses. The thiolysis reaction products showed the presence of the procyanidin (PC) and prodelphinidin (PD) structures. The 13C-NMR spectrum revealed that the condensed tannins were comprised of PD (72.4%) and PC (27.6%), and with a greater content of cis configuration rather than the trans configuration of C2-C3. The MALDI-TOF MS analysis proved the presence of PD units, and the maximum degree of polymerization (DP) was an undecamer. The antioxidant activity of condensed tannins from L. glaber leaves was evaluated by using a free radical scavenging activity assay.

  8. Chemical Composition, and Antibacterial (against Staphylococcus aureus and Free-Radical-Scavenging Activities of the Essential Oil of Scrophularia amplexicaulis Benth.

    Directory of Open Access Journals (Sweden)

    Ardalan Pasdaran

    2012-07-01

    Full Text Available Chemical composition of the essential oil obtained from the aerial parts of Scrophularia amplexicaulis Benth. was analyzed, for the first time, by the gas chromatography/mass spectrometry (GC-MS and gas chromatography/flame ionization detection (GC-FID. A total yield of 3 mg of essential oil per100 g of plant dry mass was obtained, and 27 compounds were identified, representing 97. 7 % of total oil. The essential oil were characterized by a high content of oxygenated monoterpenes and phenolic derivatives. The main constituents were eugenol (53.8%, eugenol acetate (24.5%, b -caryophyllene (5.7%, caryophyllene oxide (6.4% and aromadendrene oxide II (2.1%. The antimicrobial activity of the essential oil was tested against Staphylococcus aureus using the well diffusion method, and t he free-radical-scavenging activity was assessed by the 2,2-diphenyl-picryl-hydrazyl (DPPH assay.

  9. NMR, ESI/MS, and MALDI-TOF/MS analysis of pear juice polymeric proanthocyanidins with potent free radical scavenging activity.

    Science.gov (United States)

    Es-Safi, Nour-Eddine; Guyot, Sylvain; Ducrot, Paul-Henri

    2006-09-20

    The structure of a polymeric proanthocyanidin fraction isolated from pear juice was characterized by NMR, ESI/MS, and MALDI-TOF/MS analyses, and its antioxidant activity was investigated using the DPPH free radical scavenging method. The results obtained from 13C NMR analysis showed the predominance of signals representative of procyanidins. Typical signals in the chemical shift region between 70 and 90 ppm demonstrated the exclusive presence of epicatechin units. The results obtained through negative ESI/MS analysis showed singly and doubly charged ions corresponding to the molecular mass of procyanidins with a degree of polymerization up to 22. The spectra obtained through MALDI-TOF/MS analysis revealed the presence of two series of tannin oligomers. Supporting the observations from NMR spectroscopy, the first series consists of well-resolved tannin identified as procyanidin polymers units with chain lengths of up to 25. A second series of monogalloyl flavan-3-ols polymers with polymerization degree up to 25 were also detected. This is the first mass spectrometric evidence confirming the existence of galloylated procyanidin oligomers in pear fruits. Within each of these oligomers, various signals exist suggesting the presence of several oligomeric tannins. The antioxidant properties of the polymeric fraction were investigated through reduction of the DPPH free radical, and the results obtained showed that the polymeric fraction exhibited a higher antioxidant power compared to those of (+)-catechin and B3 procyanidin dimer.

  10. Radical-scavenging Activity of the Reaction Products of Isoeugenol with Thiol, Thiophenol, Mercaptothiazoline or Mercaptomethylimidazole Using the Induction Period Method

    Directory of Open Access Journals (Sweden)

    Seiichiro Fujisawa

    2007-08-01

    Full Text Available The reaction products in the presence of Lewis acid of isoeugenol (1 with ethanethiol, thiophenol, 2-mercaptothiazoline or 2-mercapto-1-methylimidazole (ISO-S1 – ISO-S-4 were obtained. The radical-scavenging activity of these compounds was investigated using the induction period method for polymerization of methyl methacrylate (MMA initiated by thermal decomposition of 2,2'-azobisisobutyronitrile (AIBN and benzoyl peroxide (BPO and monitored by differential scanning calorimetry (DSC. For BPO, the stoichiometric factor (number of free radicals trapped by one mole of antioxidant moiety, n declined in the order isoeugenol (1.8 > ISO-S-1 (1.6 > ISO-S-2 (1.2 > ISOS- 3 (0.9 > ISO-S-4 (0.3, whereas for AIBN, their n values were about 1, except for ISOS- 3 (0.6. The ratio of the rate constant of inhibition to that of propagation (kinh/kp for BPO declined in the order ISO-S-4 (56 > ISO-S-3 (15 > ISO-S-2 (11 >ISO-S-1 (9 > isoeugenol (8. Similarly, for AIBN the kinh/kp of the reaction products (33-57 was greater than that of isoeugenol (31. The reaction products of isoeugenol with a SH group showed greater inhibition rate constants (kinh than the parent compound isoeugenol.

  11. Some biological compounds, radical scavenging capacities and antimicrobial activities in the seeds of Nepeta italica L. and Sideritis montana L. sub sp. montana from Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Emre, I.; Kursat, M.; Yilmaz, O.; Erecevit, P.

    2011-07-01

    This study determined some biological compounds (fatty acid compositions, lipid-soluble vitamins, sterols, flavonoids), radical scavenging capacities and antimicrobial activities in the seeds of Nepeta italica L. and Sideritis montana L. subsp. montana. It was found that palmitic acid (C16:0; 8.54+-0.13-3.05+-0.04%), oleic acid (C18:1 n9, 22.41+-0.8-18.83+-0.1%) and a-inolenic acid were the dominant fatty acids in both Nepeta italica L. and Sideritis montana L. subsp. montana. It was concluded that both Nepeta italica L. and Sideritis montana L. subsp. montana contained stigmasterol and ergosterol as well as beta-sitosterol. The present findings show that Nepeta italica L. contains morin, catechin, naringin and Sideritis montana L. subsp. montana contains morin, naringenin as major flavonoids. It was also determined that methanol extracts of Nepeta italica L. and Sideritis montana L. subsp. montana were most effective against DPPH radicals. The results of the present study show that the vitamins, flavonoids and fatty acid extracts in the seeds of N. italica L. and S. montana L. subsp. montana prevented the growth of the microorganisms used in the tests at different ratios. (Author).

  12. Knockout and transgenic mice of Trp53: what have we learned about p53 in breast cancer?

    International Nuclear Information System (INIS)

    Blackburn, Anneke C; Jerry, D Joseph

    2002-01-01

    The human p53 tumor suppressor gene TP53 is mutated at a high frequency in sporadic breast cancer, and Li-Fraumeni syndrome patients who carry germline mutations in one TP53 allele have a high incidence of breast cancer. In the 10 years since the first knockout of the mouse p53 tumor suppressor gene (designated Trp53) was published, much has been learned about the contribution of p53 to biology and tumor suppression in the breast through the use of p53 transgenic and knockout mice. The original mice deficient in p53 showed no mammary gland phenotype. However, studies using BALB/c-Trp53-deficient mice have demonstrated a delayed involution phenotype and a mammary tumor phenotype. Together with other studies of mutant p53 transgenes and p53 bitransgenics, a greater understanding has been gained of the role of p53 in involution, of the regulation of p53 activity by hormones, of the effect of mouse strain and modifier genes on tumor phenotype, and of the cooperation between p53 and other oncogenic pathways, chemical carcinogens and hormonal stimulation in mammary tumorigenesis. Both p53 transgenic and knockout mice are important in vivo tools for understanding breast cancer, and are yet to be exploited for developing therapeutic strategies in breast cancer

  13. The activity of 3- and 7-hydroxyflavones as scavengers of superoxide radical anion generated from photo-excited riboflavin

    International Nuclear Information System (INIS)

    Montana, P.; Pappano, N.; Debattista, N.; Avila, V.; Posadaz, A.; Bertolotti, S.G.; Garcia, N.A.

    2003-01-01

    The visible-light irradiation of the system Riboflavin plus 3-hydroxyflavone or plus 7-hydroxyflavone, under aerobic conditions, produces a series of competitive processes that depend on the relative concentrations of the pigment and the flavones. The picture comprises photochemical mechanisms that potentially operate in nature. They mainly include the quenching of Rf singlet ( 1 Rf*) and triplet ( 3 Rf*) excited states (with bimolecular rate constants in the order of 10 9 M -1 s -1 ) and superoxide radical anion-mediated reactions. The participation of the oxidative species singlet molecular oxygen was not detected. The overall result shows chemical transformations in both Rf and 3-hydroxyflavone. No experimental evidence was found indicating any chemical reaction involving 7-hydroxyflavone. The fate of the pigment also depends on the amount of the dissolved flavonoid. At 50 mM concentrations of these compounds or higher, practically no photochemistry occurs, owing to the extensive quenching of ( 1 Rf*) When the concentration of the flavones is in the mM range or lower, ( 3 Rf*) is photogenerated. Then, the excited triplet species can be quenched mainly by the flavones through an electron-transfer process, yielding the semireduced pigment. The latter interacts with dissolved oxygen producing O 2 .- , which reacts with both the pigment and 3-hydroxyflavone. In summary, 3-hydroxyflavone and 7-hydroxyflavone participate in the generation of superoxide ion in an Rf-sensitized process, and simultaneously 3-hydroxyflavone constitutes a degradable quencher of the oxidative species. (author)

  14. Free radical inactivation of trypsin

    International Nuclear Information System (INIS)

    Cudina, Ivana; Jovanovic, S.V.

    1988-01-01

    Reactivities of free radical oxidants, radical OH, Br2-anion radical and Cl 3 COO radical and a reductant, CO2-anion radical, with trypsin and reactive protein components were determined by pulse radiolysis of aqueous solutions at pH 7, 20 0 C. Highly reactive free radicals, radical OH, Br2-anion radical and CO2-anion radical, react with trypsin at diffusion controlled rates. Moderately reactive trichloroperoxy radical, k(Cl 3 COO radical + trypsin) preferentially oxidizes histidine residues. The efficiency of inactivation of trypsin by free radicals is inversely proportional to their reactivity. The yields of inactivation of trypsin by radical OH, Br2-anion radical and CO2-anion radical are low, G(inactivation) = 0.6-0.8, which corresponds to ∼ 10% of the initially produced radicals. In contrast, Cl 3 COO radical inactivates trypsin with ∼ 50% efficiency, i.e. G(inactivation) = 3.2. (author)

  15. Severe coagulation factor VII deficiency caused by a novel homozygous mutation (p. Trp284Gly) in loop 140s.

    Science.gov (United States)

    Hao, Xiuping; Cheng, XiaoLi; Ye, Jiajia; Wang, Yingyu; Yang, LiHong; Wang, Mingshan; Jin, Yanhui

    2016-06-01

    Congenital coagulation factor VII (FVII) deficiency is a rare disorder caused by mutation in F7 gene. Herein, we reported a patient who had unexplained hematuria and vertigo with consanguineous parents. He has been diagnosed as having FVII deficiency based on the results of reduced FVII activity (2.0%) and antigen (12.8%). The thrombin generation tests verified that the proband has obstacles in producing thrombin. Direct sequencing analysis revealed a novel homozygous missense mutation p.Trp284Gly. Also noteworthy is the fact that the mutational residue belongs to structurally conserved loop 140s, which majorly undergo rearrangement after FVII activation. Model analysis indicated that the substitution disrupts these native hydrophobic interactions, which are of great importance to the conformation in the activation domain of FVIIa.

  16. Evaluation of DNA binding, DNA cleavage, protein binding, radical scavenging and in vitro cytotoxic activities of ruthenium(II) complexes containing 2,4-dihydroxy benzylidene ligands

    Energy Technology Data Exchange (ETDEWEB)

    Mohanraj, Maruthachalam; Ayyannan, Ganesan; Raja, Gunasekaran; Jayabalakrishnan, Chinnasamy, E-mail: drcjbstar@gmail.com

    2016-12-01

    The new ruthenium(II) complexes with hydrazone ligands, 4-Methyl-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL{sup 1}), 4-Methoxy-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL{sup 2}), 4-Bromo-benzoic acid (2,4-dihydroxy-benzylidene)-hydrazide (HL{sup 3}), were synthesized and characterized by various spectro analytical techniques. The molecular structures of the ligands were confirmed by single crystal X-ray diffraction technique. The DNA binding studies of the ligands and complexes were examined by absorption, fluorescence, viscosity and cyclic voltammetry methods. The results indicated that the ligands and complexes could interact with calf thymus DNA (CT-DNA) through intercalation. The DNA cleavage activity of the complexes was evaluated by gel electrophoresis assay, which revealed that the complexes are good DNA cleaving agents. The binding interaction of the ligands and complexes with bovine serum albumin (BSA) was investigated using fluorescence spectroscopic method. Antioxidant studies showed that the complexes have a strong radical scavenging properties. Further, the cytotoxic effect of the complexes examined on cancerous cell lines showed that the complexes exhibit significant anticancer activity. - Highlights: • Synthesis of ruthenium(II) hydrazone complexes • Molecular structure of the ligands was elucidated by single crystal X-ray diffraction method. • The ligands and complexes interact with CT-DNA via intercalation. • The complexes possess significant antioxidant activity against DPPH, OH and NO radicals. • The complex 6 shows higher IC{sub 50} value than the other complexes against cancer cells.

  17. Radical scavenging and antimicrobial activities of Croton zehntneri, Pterodon emarginatus and Schinopsis brasiliensis essential oils and their major constituents: estragole, trans-anethole, β-caryophyllene and myrcene.

    Science.gov (United States)

    Donati, Maddalena; Mondin, Andrea; Chen, Zheng; Miranda, Fabricio Mendes; do Nascimento, Baraquizio Braga; Schirato, Giulia; Pastore, Paolo; Froldi, Guglielmina

    2015-01-01

    The essential oils (EOs) from the Brazilian species Croton zehntneri, Pterodon emarginatus and Schinopsis brasiliensis were examined for their chemical constituents, and antioxidant and antimicrobial activities. The composition of EOs was determined by using gas chromatography coupled with mass spectrometry analysis, while the antioxidant activity was evaluated through the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays. Furthermore, the antimicrobial activity was investigated against Escherichia coli and Pseudomonas aeruginosa (both Gram-negative), Staphylococcus aureus (Gram-positive) and Candida parapsilosis (fungus). The main components of C. zehntneri, P. emarginatus and S. brasiliensis were identified as estragole, trans-anethole, β-caryophyllene and myrcene. Among the EOs, P. emarginatus showed the highest antioxidant activity, with an IC50 of 7.36 mg/mL and a Trolox equivalent antioxidant capacity of 3748 μmol/g determined by DPPH and ORAC assays, respectively. All EOs showed low activities against the bacterial strains tested, whereas the C. zehntneri oil and its main constituent estragole exhibited an appreciable antifungal activity against C. parapsilosis.

  18. Radical Scavenging Activity-Based and AP-1-Targeted Anti-Inflammatory Effects of Lutein in Macrophage-Like and Skin Keratinocytic Cells

    Directory of Open Access Journals (Sweden)

    Jueun Oh

    2013-01-01

    Full Text Available Lutein is a naturally occurring carotenoid with antioxidative, antitumorigenic, antiangiogenic, photoprotective, hepatoprotective, and neuroprotective properties. Although the anti-inflammatory effects of lutein have previously been described, the mechanism of its anti-inflammatory action has not been fully elucidated. Therefore, in the present study, we aimed to investigate the regulatory activity of lutein in the inflammatory responses of skin-derived keratinocytes or macrophages and to elucidate the mechanism of its inhibitory action. Lutein significantly reduced several skin inflammatory responses, including increased expression of interleukin-(IL- 6 from LPS-treated macrophages, upregulation of cyclooxygenase-(COX- 2 from interferon-γ/tumor necrosis-factor-(TNF- α-treated HaCaT cells, and the enhancement of matrix-metallopeptidase-(MMP- 9 level in UV-irradiated keratinocytes. By evaluating the intracellular signaling pathway and the nuclear transcription factor levels, we determined that lutein inhibited the activation of redox-sensitive AP-1 pathway by suppressing the activation of p38 and c-Jun-N-terminal kinase (JNK. Evaluation of the radical and ROS scavenging activities further revealed that lutein was able to act as a strong anti-oxidant. Taken together, our findings strongly suggest that lutein-mediated AP-1 suppression and anti-inflammatory activity are the result of its strong antioxidative and p38/JNK inhibitory activities. These findings can be applied for the preparation of anti-inflammatory and cosmetic remedies for inflammatory diseases of the skin.

  19. Loss of Cdh1 and Trp53 in the uterus induces chronic inflammation with modification of tumor microenvironment

    OpenAIRE

    Stodden, Genna R.; Lindberg, Mallory E.; King, Mandy L.; Paquet, Maril?ne; MacLean, James A.; Mann, Jordan L.; DeMayo, Francesco J.; Lydon, John P.; Hayashi, Kanako

    2014-01-01

    Type II endometrial carcinomas are estrogen independent, poorly differentiated tumors that behave in an aggressive manner. Since TP53 mutation and CDH1 inactivation occur in 80% of human endometrial type II carcinomas, we hypothesized that mouse uteri lacking both Trp53 and Cdh1 would exhibit a phenotype indicative of neoplastic transformation. Mice with conditional ablation of Cdh1 and Trp53 (Cdh1d/dTrp53d/d ) clearly demonstrate architectural features characteristic of type II endometrial c...

  20. Electrochemical and Density Functional Theory Study on the Reactivity of Fisetin and Its Radicals: Implications on in Vitro Antioxidant Activity

    Science.gov (United States)

    Marković, Zoran S.; Mentus, Slavko V.; Dimitrić Marković, Jasmina M.

    2009-12-01

    Antioxidative properties of naturally occurring flavon-3-ol, fisetin, were examined by both cyclic voltammetry and quantum-chemical based calculations. The three voltametrically detectable consecutive steps, reflected the fisetin molecular structure, catecholic structural unit in the ring B, C3-OH, and C7-OH groups in the rings C and A. Oxidation potential values, used as quantitative parameter in determining its oxidation capability, indicated good antioxidative properties found with this molecule. Oxidation of the C3'C4' dixydroxy moiety at the B ring occurred first at the lowest positive potentials. The first oxidation step induced fast intramolecular transformations in which the C3 hydroxy group disappeared and the product of this transformation participated in the second oxidation step. The highest potential of oxidation was attributed to the oxidation of C7 hydroxy group. The structural and electronic features of fisetin were investigated at the B3LYP/6-311++G** level of theory. Particularly, the interest was focused on the C3' and C4'-OH sites in the B ring and on C3-OH site in the C ring. The calculated bond dissociation enthalpy values for all OH sites of fisetin clearly indicated the importance of the B ring and C3' and C4'-OH group. The importance of keto-enol tautomerism has also been considered. The analysis also included the Mulliken spin density distribution for the radicals formed after H removal on each OH site. The results showed the higher values of the BDE on the C7-OH and C3-OH sites.

  1. Anaerobic 4-hydroxyproline utilization: Discovery of a new glycyl radical enzyme in the human gut microbiome uncovers a widespread microbial metabolic activity.

    Science.gov (United States)

    Huang, Yolanda Y; Martínez-Del Campo, Ana; Balskus, Emily P

    2018-02-06

    The discovery of enzymes responsible for previously unappreciated microbial metabolic pathways furthers our understanding of host-microbe and microbe-microbe interactions. We recently identified and characterized a new gut microbial glycyl radical enzyme (GRE) responsible for anaerobic metabolism of trans-4-hydroxy-l-proline (Hyp). Hyp dehydratase (HypD) catalyzes the removal of water from Hyp to generate Δ 1 -pyrroline-5-carboxylate (P5C). This enzyme is encoded in the genomes of a diverse set of gut anaerobes and is prevalent and abundant in healthy human stool metagenomes. Here, we discuss the roles HypD may play in different microbial metabolic pathways as well as the potential implications of this activity for colonization resistance and pathogenesis within the human gut. Finally, we present evidence of anaerobic Hyp metabolism in sediments through enrichment culturing of Hyp-degrading bacteria, highlighting the wide distribution of this pathway in anoxic environments beyond the human gut.

  2. Studies on the syntheses, structural characterization, antimicrobial-, and DPPH radical scavenging activity of the cocrystals caffeine:cinnamic acid and caffeine:eosin dihydrate

    Science.gov (United States)

    Suresh Kumar, G. S.; Seethalakshmi, P. G.; Bhuvanesh, N.; Kumaresan, S.

    2013-10-01

    Two organic cocrystals namely, caffeine:cinnamic acid [(caf)(ca)] (1) and caffeine:eosin dihydrate [(caf)(eos)]·2H2O (2) were synthesized and studied by FT-IR, TGA/DTA, and single crystal XRD. The crystal system of cocrystal 1 is triclinic with space group P-1 and Z = 2 and that of cocrystal 2 is monoclinic with space group P21/C and Z = 4. An imidazole-carboxylic acid synthon is observed in the cocrystal 1. The intermolecular hydrogen bond, O-H⋯N and π-π interactions play a major role in stabilizing 1 whereas the intermolecular hydrogen bonds, O-H⋯O, O-H⋯N, and intramolecular hydrogen bond, O-H⋯Br; along with π-π interactions together play a vital role in stabilizing the structure of 2. The antimicrobial- and DPPH radical scavenging activities of both the cocrystals were studied.

  3. Phytochemical screening and antioxidant activity of ethanolic extract and ethyl acetate fraction from basil leaf (Ocimum basilicum L.) by DPPH radical scavenging method

    Science.gov (United States)

    Warsi; Sholichah, A. R.

    2017-11-01

    Basil leaf (Ocimum basilicum L.) contains various compounds such as flavonoid, alkaloid, phenol and essential oil, so it needs to be fractionated to find out the flavonoid compound with the greatest potential as an antioxidant. This research was aimed to know the chemical compound, antioxidant potential of ethanolic extract and ethyl acetate fraction from basil leaf. The basil leaf was extracted by maceration using ethanol 70 %. The crude extract was fractionated with ethyl acetate. The ethanolic extract and ethyl acetate fraction were screened of phytochemical content including identification of flavonoids, alkaloids and polyphenolics. The antioxidant activity of the ethanolic extract and ethyl acetate fraction were tested qualitatively with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and phosphomolybdate. Its antioxidant activity was determined quantitatively using DPPH radical scavenging method. Phytochemical screening test showed that ethanolic extract and ethyl acetate fraction from basil leaf contain flavonoids, polyphenolics, and alkaloids. The qualitative analysis of antioxidant activity of ethanolic extract and ethyl acetate fraction from basil leaf showed an antioxidant activity. The IC50 value of ethanolic extract, ethyl acetate fraction and quercetin were 1,374.00±6.20 389.00±1.00 2.10±0.01μg/mL, respectively. The research showed that antioxidant activity of the ethyl acetate fraction more potential than the ethanol extract of the basil leaf, but less than quercetin.

  4. Enhancing production through optimisation of DPPH and radical ...

    African Journals Online (AJOL)

    ... of dry matter for DPPH radical scavenging activity. Methanol had the lowest value (78 mg g-1 dry matter) for polyphenol extracts and 80 mg g-1 for the DPPH radical scavenging activity. The main extract compounds were gallic acid, catechin and epicatechin. Key Words: High density lipids, polyphenol, radical scavenging ...

  5. Erectile function after radical prostatectomy

    DEFF Research Database (Denmark)

    Fode, Mikkel; Frey, Anders; Jakobsen, Henrik

    2016-01-01

    collected database and a cross-sectional, questionnaire-based study in patients following radical prostatectomy. Erectile function was assessed with the IIEF-5 and the question "Is your erectile function as good as before the surgery (yes/no)". Patients were included if they were sexually active before...

  6. Development and validation of a simple high performance thin layer chromatography method combined with direct 1,1-diphenyl-2-picrylhydrazyl assay to quantify free radical scavenging activity in wine.

    Science.gov (United States)

    Agatonovic-Kustrin, Snezana; Morton, David W; Yusof, Ahmad P

    2016-04-15

    The aim of this study was to: (a) develop a simple, high performance thin layer chromatographic (HPTLC) method combined with direct 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay to rapidly assess and compare free radical scavenging activity or anti-oxidant activity for major classes of polyphenolics present in wines; and (b) to investigate relationship between free radical scavenging activity to the total polyphenolic content (TPC) and total antioxidant capacity (TAC) in the wine samples. The most potent free radical scavengers that we tested for in the wine samples were found to be resveratrol (polyphenolic non-flavonoid) and rutin (flavonoid), while polyphenolic acids (caffeic acid and gallic acid) although present in all wine samples were found to be less potent free radical scavengers. Therefore, the total antioxidant capacity was mostly affected by the presence of resveratrol and rutin, while total polyphenolic content was mostly influenced by the presence of the less potent free radical scavengers gallic and caffeic acids. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. An Allelic Series of Trp63 Mutations Defines TAp63 as a Modifier of EEC Syndrome

    Science.gov (United States)

    Lindahl, Emma Vernersson; Garcia, Elvin L.; Mills, Alea A.

    2014-01-01

    Human Ectrodactyly, Ectodermal dysplasia, Clefting (EEC) syndrome is an autosomal dominant developmental disorder defined by limb deformities, skin defects, and craniofacial clefting. Although associated with heterozygous missense mutations in TP63, the genetic basis underlying the variable expressivity and incomplete penetrance of EEC is unknown. Here we show that mice heterozygous for an allele encoding the Trp63 p.Arg318His mutation, which corresponds to the human TP63 p.Arg279His mutation found in patients with EEC, have features of human EEC. Using an allelic series, we discovered that whereas clefting and skin defects are caused by loss of Trp63 function, limb anomalies are due to gain- and/or dominant-negative effects of Trp63. Furthermore, we identify TAp63 as a strong modifier of EEC-associated phenotypes with regard to both penetrance and expressivity. PMID:23775923

  8. Effect of Zingiber officinale Supplementation on Obesity Management with Respect to the Uncoupling Protein 1 -3826A>G and ß3-adrenergic Receptor Trp64Arg Polymorphism.

    Science.gov (United States)

    Ebrahimzadeh Attari, Vahideh; Asghari Jafarabadi, Mohammad; Zemestani, Maryam; Ostadrahimi, Alireza

    2015-07-01

    The present study aimed to investigate the effect of ginger (Zingiber officinale) supplementation on some obesity-associated parameters, with nutrigenetics approach. Accordingly, 80 eligible obese women (aged 18-45 years) were randomly assigned to receive either ginger (2-g ginger rhizomes powder as two 1-g tablets per day) or placebo supplements (corn starch with the same amount) for 12 weeks. Subjects were tested for changes in body weight, body mass index, waist and hip circumferences, body composition, appetite score, and dietary intake. Moreover, participants were genotyped for the -3826A>G and Trp64Arg polymorphisms of uncoupling protein 1 and ß3-adrenergic receptor genes, respectively. Over 12 weeks, ginger supplementation resulted in a slight but statistically significant decrease in all anthropometric measurements and total appetite score as compared with placebo group, which were more pronounced in subjects with the AA genotype for uncoupling protein 1 and Trp64Trp genotype for ß3-adrenergic receptor gene. However, there was no significant difference in changes of body composition and total energy and macronutrients intake between groups. In conclusion, our findings suggest that ginger consumption has potential in managing obesity, accompanying with an intervention-genotype interaction effect. However, further clinical trials need to explore ginger's efficacy as an anti-obesity agent in the form of powder, extract, or its active components. Copyright © 2015 John Wiley & Sons, Ltd.

  9. The core domain as the force sensor of the yeast mechanosensitive TRP channel.

    Science.gov (United States)

    Su, Zhenwei; Anishkin, Andriy; Kung, Ching; Saimi, Yoshiro

    2011-12-01

    Stretch-activated conductances are commonly encountered in careful electric recordings. Those of known proteins (TRP, MscL, MscS, K(2p), Kv, etc.) all share a core, which houses the ion pathway and the gate, but no recognizable force-sensing domain. Like animal TRPs, the yeast TRPY1 is polymodal, activated by stretch force, Ca(2+), etc. To test whether its S5-S6 core senses the stretch force, we tried to uncouple it from the peripheral domains by strategic peptide insertions to block the covalent core-periphery interactions. Insertion of long unstructured peptides should distort, if not disrupt, protein structures that transmit force. Such insertions between S6 and the C-terminal tail largely removed Ca(2+) activation, showing their effectiveness. However, such insertions as well as those between S5 and the N-terminal region, which includes S1-S4, did not significantly alter mechanosensitivity. Even insertions at both locations flanking the S5-S6 core did not much alter mechanosensitivity. Tryptophan scanning mutations in S5 were also constructed to perturb possible noncovalent core-periphery contacts. The testable tryptophan mutations also have little or no effects on mechanosensitivity. Boltzmann fits of the wild-type force-response curves agree with a structural homology model for a stretch-induced core expansion of ~2 nm(2) upon opening. We hypothesize that membrane tension pulls on S5-S6, expanding the core and opening the TRPY1 gate. The core being the major force sensor offers the simplest, though not the only, explanation of why so many channels of disparate designs are mechanically sensitive. Compared with the bacterial MscL, TRPY1 is much less sensitive to force, befitting a polymodal channel that relies on multiple stimuli.

  10. Chemical composition, botanical evaluation and screening of radical scavenging activity of collected pollen by the stingless bees Melipona rufiventris (Uruçu-amarela).

    Science.gov (United States)

    Silva, Tania M S; Camara, Celso A; Lins, Antonio C S; Agra, Maria de Fátima; Silva, Eva M S; Reis, Igor T; Freitas, Breno M

    2009-06-01

    Stingless bees in Brazil are indigenous and found all over the country. Bee pollen is used for its nutritional value in the human diet. It is made up of natural flower pollen mixed with nectar and bee secretions. In order to evaluate the chemical composition, free radical scavenging activity, and botanical origin, sample of pollen loads from stingless bee, Melipona rufiventris (Uruçu amarela) was studied. The EtOAc extract of pollen of Melipona rufiventris yielded the following compounds: p-hydroxycinnamic acid, dihydroquercetin, isorhamnetin, isorhamnetin3-O-(6'-O-E-p-coumaroyl)-beta-D-glucopyranoside, luteolin, and quercetin. This is the first report of the isolation of isorhamnetin3-O-(6'O-E-p-coumaroyl)beta-D-glucopyranoside from pollen. The free radicalscavenging activities of different solvent extracts of pollen were determined using DPPH assay. This activity decreases in the order: EtOAc>EtOH>Hexane extract. It appears that the EtOAc extract of the pollen is a good scavenger of active oxygen species. The botanical evaluation of pollen loads showed the composition by two pollen types, with the dominant type (97.3%) being Scopariadulcis (L.) (Scrophulariaceae) and the minor one Senna obtusifolia (L.) Irwin & Barneby (Fabaceae). This suggests a specific foraging behavior in Melipona rufiventris bees, even in an environment with such a rich botanical diversity as the Northeastern Brazil.

  11. Synthesis, X-ray crystallography, spectroscopic characterization and spectroscopic/electrochemical evidence of formation of phenoxy free radical in active center analogs of galactose oxidase - [Cu(Salgly)H₂O] and [Cu(Salphenylalanine)H₂O].

    Science.gov (United States)

    Das, Biva; Medhi, Okhil K

    2013-03-01

    The formation of phenolate free radical is the factor of high turnover for catalytic activity of galactose oxidase (GO) compared to that by inorganic complexes. A new active center analog of GO, [Cu(II)(Salphenylalanine)H(2)O] have been synthesized and its single crystal X-ray analysis was done. In aqueous surfactant micellar solution chemical oxidation as well as electrochemical oxidation of structural models of galactose oxidase - [Cu(II)Salgly·H(2)O] and [Cu(II)(Salphenylalanine)·H(2)O], have been found to generate free radical originating at the phenolate group. Formation of the free radical have been proved by electron paramagnetic resonance spectroscopy, electronic spectroscopy and electrochemistry. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Visible light activity of pulsed layer deposited BiVO{sub 4}/MnO{sub 2} films decorated with gold nanoparticles: The evidence for hydroxyl radicals formation

    Energy Technology Data Exchange (ETDEWEB)

    Trzciński, Konrad, E-mail: trzcinskikonrad@gmail.com [Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk (Poland); Szkoda, Mariusz [Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk (Poland); Sawczak, Mirosław [Centre for Plasma and Laser Engineering, The Szewalski Institute of Fluid Flow Machinery, Fiszera 14, 80-231 Gdansk (Poland); Karczewski, Jakub [Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk (Poland); Lisowska-Oleksiak, Anna [Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk (Poland)

    2016-11-01

    Highlights: • The BiVO{sub 4} + MnO{sub 2} photoactive layers were prepared by pulsed laser deposition method. • Prepared layers can act as photoanodes for water splitting. • The thin BiVO{sub 4} + MnO{sub 2} film can be used as photocatalyst for methylene blue degradation. • The formation of hydroxyl radicals during photocatalys illumination has been proved. • The dropcasted GNP improved significantly photocatalytic properties of tested layers. - Abstract: Thin films containing BiVO{sub 4} and MnO{sub 2} deposited on FTO and modified by Au nanoparticles were studied towards their photoelectrochemical and photocatalytical activities in an aqueous electrolyte. Electrodes were prepared by the pulsed laser deposition (PLD) method. The surfactant-free ablation process was used for preparation of the gold nanoparticles (GNP) water suspension. Obtained layers of varied thicknesses (27–115 nm) were characterized using Raman spectroscopy, UV–vis spectroscopy and scanning electron microscopy. Electrochemical methods such as electrochemical impedance spectroscopy, linear voltammetry and chronoamperometry under visible light illumination and in the dark were applied to characterize layers as photoanodes. Simple modification of the BiVO{sub 4} + MnO{sub 2} layer by drop-casting of small amount of colloidal gold (1.5 × 10{sup −14} mol of GNP on 1 cm{sup 2}) leads to enhancement of the generated photocurrent recorded at E = 0.5 V vs. Ag/AgCl (0.1 M KCl) from 63 μA/cm{sup 2} to 280 μA/cm{sup 2}. Photocatalytical studies were also exploited towards decomposition of methylene blue (MB). A possible mechanism of MB photodegradation was proposed. The formation of hydroxyl radicals was detected by photoluminescence spectra using terephthalic acid as the probe molecule.

  13. Dietary Protection Against Free Radicals: A Case for Multiple Testing to Establish Structure-activity Relationships for Antioxidant Potential of Anthocyanic Plant Species

    Directory of Open Access Journals (Sweden)

    Chiara Cheng Lim

    2009-03-01

    Full Text Available DNA damage by reactive species is associated with susceptibility to chronic human degenerative disorders. Anthocyanins are naturally occurring antioxidants, that may prevent or reverse such damage. There is considerable interest in anthocyanic food plants as good dietary sources, with the potential for reducing susceptibility to chronic disease. While structure-activity relationships have provided guidelines on molecular structure in relation to free hydroxyl- radical scavenging, this may not cover the situation in food plants where the anthocyanins are part of a complex mixture, and may be part of complex structures, including anthocyanic vacuolar inclusions (AVIs. Additionally, new analytical methods have revealed new structures in previously-studied materials. We have compared the antioxidant activities of extracts from six anthocyanin-rich edible plants (red cabbage, red lettuce, blueberries, pansies, purple sweetpotato skin, purple sweetpotato flesh and Maori potato flesh using three chemical assays (DPPH, TRAP and ORAC, and the in vitro Comet assay. Extracts from the flowering plant, lisianthus, were used for comparison. The extracts showed differential effects in the chemical assays, suggesting that closely related structures have different affinities to scavenge different reactive species. Integration of anthocyanins to an AVI led to more sustained radical scavenging activity as compared with the free anthocyanin. All but the red lettuce extract could reduce endogenous DNA damage in HT-29 colon cancer cells. However, while extracts from purple sweetpotato skin and flesh, Maori potato and pansies, protected cells against subsequent challenge by hydrogen peroxide at 0oC, red cabbage extracts were pro-oxidant, while other extracts had no effect. When the peroxide challenge was at 37oC, all of the extracts appeared pro-oxidant. Maori potato extract, consistently the weakest antioxidant in all the chemical assays, was more effective in the

  14. Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L., J. oxycedrus (L., J. phoenicea (L. and Tetraclinis articulata (L.

    Directory of Open Access Journals (Sweden)

    Meryem El Jemli

    2016-01-01

    Full Text Available Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC, and ferric reducing antioxidant power (FRAP assays. Also the total phenolic and flavonoids contents of the extracts were determined spectrophotometrically. Results. All the extracts showed interesting antioxidant activities compared to the standard antioxidants (butylated hydroxytoluene (BHT, quercetin, and Trolox. The aqueous extract of Juniperus oxycedrus showed the highest antioxidant activity as measured by DPPH, TEAC, and FRAP assays with IC50 values of 17.91±0.37 μg/mL, 19.80±0.55 μg/mL, and 24.23±0.07 μg/mL, respectively. The strong correlation observed between antioxidant capacities and their total phenolic contents indicated that phenolic compounds were a major contributor to antioxidant properties of these plants extracts. Conclusion. These results suggest that the aqueous extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus phoenicea, and Tetraclinis articulata can constitute a promising new source of natural compounds with antioxidants ability.

  15. Radical-Scavenging Activity and Ferric Reducing Ability of Juniperus thurifera (L.), J. oxycedrus (L.), J. phoenicea (L.) and Tetraclinis articulata (L.).

    Science.gov (United States)

    El Jemli, Meryem; Kamal, Rabie; Marmouzi, Ilias; Zerrouki, Asmae; Cherrah, Yahia; Alaoui, Katim

    2016-01-01

    Objective. The aim of this work is to study and compare the antioxidant properties and phenolic contents of aqueous leaf extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus Phoenicea, and Tetraclinis articulata from Morocco. Methods. Antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging ability, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP) assays. Also the total phenolic and flavonoids contents of the extracts were determined spectrophotometrically. Results. All the extracts showed interesting antioxidant activities compared to the standard antioxidants (butylated hydroxytoluene (BHT), quercetin, and Trolox). The aqueous extract of Juniperus oxycedrus showed the highest antioxidant activity as measured by DPPH, TEAC, and FRAP assays with IC50 values of 17.91 ± 0.37 μg/mL, 19.80 ± 0.55 μg/mL, and 24.23 ± 0.07 μg/mL, respectively. The strong correlation observed between antioxidant capacities and their total phenolic contents indicated that phenolic compounds were a major contributor to antioxidant properties of these plants extracts. Conclusion. These results suggest that the aqueous extracts of Juniperus thurifera, Juniperus oxycedrus, Juniperus phoenicea, and Tetraclinis articulata can constitute a promising new source of natural compounds with antioxidants ability.

  16. Arabidopsis annexin1 mediates the radical-activated plasma membrane Ca²+- and K+-permeable conductance in root cells.

    Science.gov (United States)

    Laohavisit, Anuphon; Shang, Zhonglin; Rubio, Lourdes; Cuin, Tracey A; Véry, Anne-Aliénor; Wang, Aihua; Mortimer, Jennifer C; Macpherson, Neil; Coxon, Katy M; Battey, Nicholas H; Brownlee, Colin; Park, Ohkmae K; Sentenac, Hervé; Shabala, Sergey; Webb, Alex A R; Davies, Julia M

    2012-04-01

    Plant cell growth and stress signaling require Ca²⁺ influx through plasma membrane transport proteins that are regulated by reactive oxygen species. In root cell growth, adaptation to salinity stress, and stomatal closure, such proteins operate downstream of the plasma membrane NADPH oxidases that produce extracellular superoxide anion, a reactive oxygen species that is readily converted to extracellular hydrogen peroxide and hydroxyl radicals, OH•. In root cells, extracellular OH• activates a plasma membrane Ca²⁺-permeable conductance that permits Ca²⁺ influx. In Arabidopsis thaliana, distribution of this conductance resembles that of annexin1 (ANN1). Annexins are membrane binding proteins that can form Ca²⁺-permeable conductances in vitro. Here, the Arabidopsis loss-of-function mutant for annexin1 (Atann1) was found to lack the root hair and epidermal OH•-activated Ca²⁺- and K⁺-permeable conductance. This manifests in both impaired root cell growth and ability to elevate root cell cytosolic free Ca²⁺ in response to OH•. An OH•-activated Ca²⁺ conductance is reconstituted by recombinant ANN1 in planar lipid bilayers. ANN1 therefore presents as a novel Ca²⁺-permeable transporter providing a molecular link between reactive oxygen species and cytosolic Ca²⁺ in plants.

  17. Interaction between the Gly460Trp alpha-adducin gene variant and diuretics on the risk of myocardial infarction

    NARCIS (Netherlands)

    van Wieren-de Wijer, Diane B M A; Maitland-van der Zee, Anke-Hilse; de Boer, Anthonius; Kroon, Abraham A; de Leeuw, Peter W; Schiffers, Paul; Janssen, Rob G J H; Psaty, Bruce M; van Duijn, Cornelia M; Stricker, Bruno H Ch; Klungel, Olaf H

    INTRODUCTION: The Gly460Trp variant of the alpha-adducin gene has been associated with the salt-sensitive and diuretic responsive form of hypertension. OBJECTIVE: The aim of the study was to determine whether the alpha-adducin 460Trp variant allele modifies the risk-lowering effect of diuretics on

  18. Chromatographic fingerprinting and free-radical scavenging activity of ethanol extracts of Muntingia calabura L. leaves and stems

    Directory of Open Access Journals (Sweden)

    William Patrick Cruiz Buhian

    2017-02-01

    Conclusions: M. calabura exhibited very high antioxidant activity in its leaves and stems ethanol extracts, both of which are used in traditional medicine. The TLC results demonstrated the presence of diverse secondary metabolites in the leaf and stem ethanol extracts, indicating that the antioxidant activity, including other bioactivities may be attributed to these phytochemical constituents. This paper has reported for the first time the TLC fingerprinting of M. calabura using visible light, UV 254 nm, UV 366 and post-derivatization with vanillin-spray to visualize separate spots on TLC plates.

  19. Daring to Marry: Marriage Equality Activism After Proposition 8 as Challenge to the Assimilationist/Radical Binary in Queer Studies.

    Science.gov (United States)

    Weber, Shannon

    2015-01-01

    I analyze three case studies of marriage equality activism and marriage equality-based groups after the passage of Proposition 8 in California. Evaluating the JoinTheImpact protests of 2008, the LGBTQ rights group GetEQUAL, and the group One Struggle One Fight, I argue that these groups revise queer theoretical arguments about marriage equality activism as by definition assimilationist, homonormative, and single-issue. In contrast to such claims, the cases studied here provide a snapshot of heterogeneous, intersectional, and coalition-based social justice work in which creative methods of protest, including direct action and flash mobs, are deployed in militant ways for marriage rights and beyond.

  20. Engineering a horseradish peroxidase C stable to radical attacks by mutating multiple radical coupling sites.

    Science.gov (United States)

    Kim, Su Jin; Joo, Jeong Chan; Song, Bong Keun; Yoo, Young Je; Kim, Yong Hwan

    2015-04-01

    Peroxidases have great potential as industrial biocatalysts. In particular, the oxidative polymerization of phenolic compounds catalyzed by peroxidases has been extensively examined because of the advantage of this method over other conventional chemical methods. However, the industrial application of peroxidases is often limited because of their rapid inactivation by phenoxyl radicals during oxidative polymerization. In this work, we report a novel protein engineering approach to improve the radical stability of horseradish peroxidase isozyme C (HRPC). Phenylalanine residues that are vulnerable to modification by the phenoxyl radicals were identified using mass spectrometry analysis. UV-Vis and CD spectra showed that radical coupling did not change the secondary structure or the active site of HRPC. Four phenylalanine (Phe) residues (F68, F142, F143, and F179) were each mutated to alanine residues to generate single mutants to examine the role of these sites in radical coupling. Despite marginal improvement of radical stability, each single mutant still exhibited rapid radical inactivation. To further reduce inactivation by radical coupling, the four substitution mutations were combined in F68A/F142A/F143A/F179A. This mutant demonstrated dramatic enhancement of radical stability by retaining 41% of its initial activity compared to the wild-type, which was completely inactivated. Structure and sequence alignment revealed that radical-vulnerable Phe residues of HPRC are conserved in homologous peroxidases, which showed the same rapid inactivation tendency as HRPC. Based on our site-directed mutagenesis and biochemical characterization, we have shown that engineering radical-vulnerable residues to eliminate multiple radical coupling can be a good strategy to improve the stability of peroxidases against radical attack. © 2014 Wiley Periodicals, Inc.

  1. The role of supplemental ultraviolet-B radiation in altering the metabolite profile, essential oil content and composition, and free radical scavenging activities of Coleus forskohlii, an indigenous medicinal plant.

    Science.gov (United States)

    Takshak, Swabha; Agrawal, S B

    2016-04-01

    The effects of supplemental ultraviolet-B (s-UV-B; 3.6 kJ m(-2) day(-1) above ambient) radiation were investigated on plant metabolite profile, essential oil content and composition, and free radical scavenging capacities of methanolic extracts of Coleus forskohlii (an indigenous medicinal plant) grown under field conditions. Essential oil was isolated using hydrodistillation technique while alterations in metabolite profile and oil composition were determined via gas chromatography-mass spectroscopy (GC-MS). Leaf and root methanolic extracts were investigated via various in vitro assays for their DPPH radical-, superoxide radical-, hydrogen peroxide-, hydroxyl radical-, and nitric oxide radical scavenging activities, ferrous ion chelating activity, and reducing power. Phytochemical analysis revealed the presence of alkaloids, anthocyanins, coumarins, flavonoids, glycosides, phenols, saponins, steroids, tannins, and terpenoids. Oil content was found to be reduced (by ∼7 %) in supplemental UV-B (s-UV-B) treated plants; the composition of the plant extracts as well as essential oil was also considerably altered. Methanolic extracts from treated plant organs showed more potency as free radical scavengers (their EC50 values being lower than their respective controls). Anomalies were observed in Fe(2+) chelating activity for both leaves and roots. The present study concludes that s-UV-B adversely affects oil content in C. forskohlii and also alters the composition and contents of metabolites in both plant extracts and oil. The results also denote that s-UV-B treated plant organs might be more effective in safeguarding against oxidative stress, though further studies are required to authenticate these findings.

  2. Structural domains required for channel function of the mouse transient receptor potential protein homologue TRP1beta.

    Science.gov (United States)

    Engelke, Michael; Friedrich, Olaf; Budde, Petra; Schäfer, Christina; Niemann, Ursula; Zitt, Christof; Jüngling, Eberhard; Rocks, Oliver; Lückhoff, Andreas; Frey, Jürgen

    2002-07-17

    Transient receptor potential proteins (TRP) are supposed to participate in the formation of store-operated Ca(2+) influx channels by co-assembly. However, little is known which domains facilitate the interaction of subunits. Contribution of the N-terminal coiled-coil domain and ankyrin-like repeats and the putative pore region of the mouse TRP1beta (mTRP1beta) variant to the formation of functional cation channels were analyzed following overexpression in HEK293 (human embryonic kidney) cells. MTRP1beta expressing cells exhibited enhanced Ca(2+) influx and enhanced whole-cell membrane currents compared to mTRP1beta deletion mutants. Using a yeast two-hybrid assay only the coiled-coil domain facilitated homodimerization of the N-terminus. These results suggest that the N-terminus of mTRP1beta is required for structural organization thus forming functional channels.

  3. A survey on the biochemical parameters in serum of the Azarbaijan buffaloes with TRP

    Directory of Open Access Journals (Sweden)

    Gh. Mousavi

    2010-02-01

    Full Text Available TRP disease is one of the prevalent disease in cows and buffaloes that most common in dairy cows feed by prepared foods but cases occur infrequently in buffaloes, beef cattle, sheep and goats. In this research 15 Azerbaijan buffaloes with TRP were studied. Firstly affected buffaloes were diagnosed based on clinical signs. The blood samples were obtained from the related animals and after separation blood serum by centrifuging, the biochemical tests, such as sodium, potassium, Glucose, phosphorus, albumin and calcium levels in serum were measured. The mean levels of sodium, potassium, Glucose, phosphorus, albumin and calcium in buffaloes with TRP were 112 mEq/Lit, 3.11 mEq/Lit, 42.29 mg/dl, 3.84 mg/dl, 544 mg/dl, 8.60 mg/dl. In this study the mean levels of sodium, potassium, phosphorus in buffaloes with TRP was less than the normal buffaloes and the mean levels of calcium, Glucose as such as the normal animals and the mean levels of albumin was higher than the normal buffaloes.

  4. Rate constant and reaction coordinate of Trp-cage folding in explicit water

    NARCIS (Netherlands)

    Juraszek, J.; Bolhuis, P.G.

    2008-01-01

    We report rate constant calculations and a reaction coordinate analysis of the rate-limiting folding and unfolding process of the Trp-cage mini-protein in explicit solvent using transition interface sampling. Previous transition path sampling simulations revealed that in this (un)folding process the

  5. Alpha-adducin Gly460Trp polymorphism and renal hemodynamics in essential hypertension

    NARCIS (Netherlands)

    Beeks, Esther; van der Klauw, Melanie M; Kroon, Abraham A; Spiering, Wilko; Fuss-Lejeune, Monique J M J; de Leeuw, Peter W

    2004-01-01

    Previous studies have shown an association between the alpha-adducin Gly460Trp polymorphism and salt-sensitive hypertension. Not much is known about the effects of the variants of this polymorphism on renal hemodynamics and function. Therefore, we performed the present study to investigate the

  6. Sampling the equilibrium kinetic network of Trp-cage in explicit solvent

    NARCIS (Netherlands)

    Du, W.; Bolhuis, P.G.

    2014-01-01

    We employed the single replica multiple state transition interface sampling (MSTIS) approach to sample the kinetic (un) folding network of Trp-cage mini-protein in explicit water. Cluster analysis yielded 14 important metastable states in the network. The MSTIS simulation thus resulted in a full 14

  7. A direct comparison of protein structure in the gas and solution phase: the Trp-cage

    DEFF Research Database (Denmark)

    Patriksson, Alexandra; Adams, Christopher M; Kjeldsen, Frank

    2007-01-01

    Molecular dynamics simulations of zwitterions of the Trp-cage protein in the gas phase show that the most stable ion in vacuo has preserved the charge locations acquired in solution. A direct comparison of the gas and solution-phase structures reveals that, despite the similarity in charge location...

  8. Urea and Guanidinium Induced Denaturation of a Trp-Cage Miniprotein

    Czech Academy of Sciences Publication Activity Database

    Heyda, Jan; Kožíšek, Milan; Bednárová, Lucie; Thompson, G.; Konvalinka, Jan; Vondrášek, Jiří; Jungwirth, Pavel

    2011-01-01

    Roč. 115, č. 28 (2011), s. 8910-8924 ISSN 1520-6106 R&D Projects: GA MŠk LC512; GA ČR GA203/08/0114 Institutional research plan: CEZ:AV0Z40550506 Keywords : trp-cage denaturation * urea * guanidinium * molecular dynamics Subject RIV: CC - Organic Chemistry Impact factor: 3.696, year: 2011

  9. Total phenolic contents and free-radical scavenging activities of grape (Vitis vinifera L.) and grape products.

    Science.gov (United States)

    Keser, Serhat; Celik, Sait; Turkoglu, Semra

    2013-03-01

    Grape is one of the world's largest fruit crops, with an approximate annual production of 58 million metric tons, and it is well known that the grape skins, seeds and stems, waste products generated during wine and grape juice processing, are rich sources of polyphenols. It contains flavonoids, phenolic acids and stilbenes. In this study, we tried to determine antioxidant properties and phenolic contents of grape and grape products (fresh fruit, seed, dried fruit, molasses, pestil, vinegar) of ethanol and water extracts. Antioxidant properties of extracts were investigated by DPPH(√), ABTS(√+), superoxide, H(2)O(2) scavenging, reducing power, metal chelating activity and determination of total phenolic contents. The seed extracts revealed highest ABTS(√+), DPPH(√), H(2)O(2) scavenging and reducing power activities. Furthermore, these extracts showed higher total phenolic contents than other grape product extracts.

  10. Intracellular ROS protection efficiency and free radical-scavenging activity of quercetin and quercetin-encapsulated liposomes.

    Science.gov (United States)

    Rezaei-Sadabady, Rogaie; Eidi, Akram; Zarghami, Nosratollah; Barzegar, Abolfazl

    2016-01-01

    Quercetin (3,5,7,3',4'-pentahydroxyflavone) is a natural bio-flavonoid originating from fruits, vegetables, seeds, berries, and tea. The antioxidant activity of quercetin and its protective effects against cardiovascular disorders, anti-cancer, anti-inflammatory, and anti-viral activities have been extensively documented; however, the clinical request of quercetin in cancer treatment is significantly limited due to its very poor delivery features. In order to increase the hydrophilicity and drug delivery capability, we encapsulated quercetin into liposomes. Our data indicated that liposomal quercetin can significantly improve the solubility and bioavailability of quercetin and can be used as an effective antioxidant for ROS protection within the polar cytoplasm, and the nano-sized quercetin encapsulated by liposomes enhanced the cellular uptake (cancer cell human MCF_7). Quercetin has many pharmaceutical applications, many of which arise from its potent antioxidant properties. The present research examined the antioxidant activities of quercetin in polar solvents by a comparative study using reduction of ferric iron in aqueous medium, intracellular ROS/toxicity assays, and reducing DPPH assays. Cell viability and ROS assays demonstrated that quercetin was able to penetrate into the polar medium inside the cells and to protect them against the highly toxic and deadly belongings of cumene hydroperoxide. The purpose of this study was to determine whether a liposomal formulation of quercetin can suggestively improve its solubility and bioavailability and can be a possible request in the treatment of tumor. The authors encapsulated quercetin in a liposomal delivery system. They studied the in vitro effects of this compound on proliferation using human MCF-7 carcinoma cells. The activity of liposomal quercetin was equal to or better than that of free quercetin at equimolar concentrations. Our data indicated that liposomal quercetin can significantly improve the

  11. Revisiting the Role of TRP, Orai, and ASIC Channels in the Pulmonary Arterial Response to Hypoxia

    Directory of Open Access Journals (Sweden)

    Roberto V. Reyes

    2018-05-01

    Full Text Available The pulmonary arteries are exquisitely responsive to oxygen changes. They rapidly and proportionally contract as arterial PO2 decrease, and they relax as arterial PO2 is re-established. The hypoxic pulmonary vasoconstriction (HPV is intrinsic since it does not require neural or endocrine factors, as evidenced in isolated vessels. On the other hand, pulmonary arteries also respond to sustained hypoxia with structural and functional remodeling, involving growth of smooth muscle medial layer and later recruitment of adventitial fibroblasts, secreted mitogens from endothelium and changes in the response to vasoconstrictor and vasodilator stimuli. Hypoxic pulmonary arterial vasoconstriction and remodeling are relevant biological responses both under physiological and pathological conditions, to explain matching between ventilation and perfusion, fetal to neonatal transition of pulmonary circulation and pulmonary artery over-constriction and thickening in pulmonary hypertension. Store operated channels (SOC and receptor operated channels (ROC are plasma membrane cationic channels that mediate calcium influx in response to depletion of internal calcium stores or receptor activation, respectively. They are involved in both HPV and pathological remodeling since their pharmacological blockade or genetic suppression of several of the Stim, Orai, TRP, or ASIC proteins in SOC or ROC complexes attenuate the calcium increase, the tension development, the pulmonary artery smooth muscle proliferation, and pulmonary arterial hypertension. In this Mini Review, we discussed the evidence obtained in in vivo animal models, at the level of isolated organ or cells of pulmonary arteries, and we identified and discussed the questions for future research needed to validate these signaling complexes as targets against pulmonary hypertension.

  12. Platelet dysfunction associated with the novel Trp29Cys thromboxane A₂ receptor variant.

    Science.gov (United States)

    Mumford, A D; Nisar, S; Darnige, L; Jones, M L; Bachelot-Loza, C; Gandrille, S; Zinzindohoue, F; Fischer, A-M; Mundell, S J; Gaussem, P

    2013-03-01

    Genetic variations that affect the structure of the thromboxane A2 receptor (TP receptor) provide insights into the function of this key platelet and vascular receptor, but are very rare in unselected populations. To determine the functional consequences of the TP receptor Trp29Cys (W29C) substitution. We performed a detailed phenotypic analysis of an index case (P1) with reduced platelet aggregation and secretion responses to TP receptor pathway activators, and a heterozygous TP receptor W29C substitution. An analysis of the variant W29C TP receptor expressed in heterologous cells was performed. Total TP receptor expression in platelets from P1 was similar to that of controls, but there was reduced maximum binding and reduced affinity of binding to the TP receptor antagonist [(3) H]SQ29548. HEK293 cells transfected with W29C TP receptor cDNA showed similar total TP receptor expression to wild-type (WT) controls. However, the TP receptor agonist U46619 was less potent at inducing rises in cytosolic free Ca(2+) in HEK293 cells expressing the W29C TP receptor than in WT controls, indicating reduced receptor function. Immunofluorescence microscopy and cell surface ELISA showed intracellular retention and reduced cell surface expression of the W29C TP receptor in HEK293 cells. Consistent with the platelet phenotype, both maximum binding and the affinity of binding of [(3) H]SQ29548 to the W29C TP receptor were reduced compared to WT controls. These findings extend the phenotypic description of the very rare disorder TP receptor deficiency, and show that the W29C substitution reduces TP receptor function by reducing surface receptor expression and by disrupting ligand binding. © 2012 International Society on Thrombosis and Haemostasis.

  13. Modular Organization of the NusA- and NusG-Stimulated RNA Polymerase Pause Signal That Participates in the Bacillus subtilis trp Operon Attenuation Mechanism.

    Science.gov (United States)

    Mondal, Smarajit; Yakhnin, Alexander V; Babitzke, Paul

    2017-07-15

    The Bacillus subtilis trpEDCFBA operon is regulated by a transcription attenuation mechanism in which tryptophan-activated TRAP binds to the nascent transcript and blocks the formation of an antiterminator structure such that the formation of an overlapping intrinsic terminator causes termination in the 5' untranslated region (5' UTR). In the absence of bound TRAP, the antiterminator forms and transcription continues into the trp genes. RNA polymerase pauses at positions U107 and U144 in the 5' UTR. The general transcription elongation factors NusA and NusG stimulate pausing at both positions. NusG-stimulated pausing at U144 requires sequence-specific contacts with a T tract in the nontemplate DNA (ntDNA) strand within the paused transcription bubble. Pausing at U144 participates in a trpE translation repression mechanism. Since U107 just precedes the critical overlap between the antiterminator and terminator structures, pausing at this position is thought to participate in attenuation. Here we carried out in vitro pausing and termination experiments to identify components of the U107 pause signal and to determine whether pausing affects the termination efficiency in the 5' UTR. We determined that the U107 and U144 pause signals are organized in a modular fashion containing distinct RNA hairpin, U-tract, and T-tract components. NusA-stimulated pausing was affected by hairpin strength and the U-tract sequence, whereas NusG-stimulated pausing was affected by hairpin strength and the T-tract sequence. We also determined that pausing at U107 results in increased TRAP-dependent termination in the 5' UTR, implying that NusA- and NusG-stimulated pausing participates in the trp operon attenuation mechanism by providing additional time for TRAP binding. IMPORTANCE The expression of several bacterial operons is controlled by regulated termination in the 5' untranslated region (5' UTR). Transcription attenuation is defined as situations in which the binding of a regulatory

  14. Ac-Trp-DPhe(p-I)-Arg-Trp-NH2, a 250-Fold Selective Melanocortin-4 Receptor (MC4R) Antagonist over the Melanocortin-3 Receptor (MC3R), Affects Energy Homeostasis in Male and Female Mice Differently.

    Science.gov (United States)

    Lensing, Cody J; Adank, Danielle N; Doering, Skye R; Wilber, Stacey L; Andreasen, Amy; Schaub, Jay W; Xiang, Zhimin; Haskell-Luevano, Carrie

    2016-09-21

    The melanocortin-4 receptor (MC4R) has been indicated as a therapeutic target for metabolic disorders such as anorexia, cachexia, and obesity. The current study investigates the in vivo effects on energy homeostasis of a 15 nM MC4R antagonist SKY2-23-7, Ac-Trp-DPhe(p-I)-Arg-Trp-NH2, that is a 3700 nM melanocortin-3 receptor (MC3R) antagonist with minimal MC3R and MC4R agonist activity. When monitoring both male and female mice in TSE metabolic cages, sex-specific responses were observed in food intake, respiratory exchange ratio (RER), and energy expenditure. A 7.5 nmol dose of SKY2-23-7 increased food intake, increased RER, and trended toward decreasing energy expenditure in male mice. However, this compound had minimal effect on female mice's food intake and RER at the 7.5 nmol dose. A 2.5 nmol dose of SKY2-23-7 significantly increased female food intake, RER, and energy expenditure while having a minimal effect on male mice at this dose. The observed sex differences of SKY2-23-7 administration result in the discovery of a novel chemical probe for elucidating the molecular mechanisms of the sexual dimorphism present within the melanocortin pathway. To further explore the melanocortin sexual dimorphism, hypothalamic gene expression was examined. The mRNA expression of the MC3R and proopiomelanocortin (POMC) were not significantly different between sexes. However, the expression of agouti-related peptide (AGRP) was significantly higher in female mice which may be a possible mechanism for the sex-specific effects observed with SKY2-23-7.

  15. Radical advancement in multi-spectral imaging for autonomous vehicles (UAVs, UGVs, and UUVs) using active compensation.

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Brian F.; Bagwell, Brett E.; Wick, David Victor

    2007-01-01

    The purpose of this LDRD was to demonstrate a compact, multi-spectral, refractive imaging systems using active optical compensation. Compared to a comparable, conventional lens system, our system has an increased operational bandwidth, provides for spectral selectivity and, non-mechanically corrects aberrations induced by the wavelength dependent properties of a passive refractive optical element (i.e. lens). The compact nature and low power requirements of the system lends itself to small platforms such as autonomous vehicles. In addition, the broad spectral bandwidth of our system would allow optimized performance for both day/night use, and the multi-spectral capability allows for spectral discrimination and signature identification.

  16. Exploring the Theories of Radicalization

    Directory of Open Access Journals (Sweden)

    Maskaliūnaitė Asta

    2015-12-01

    Full Text Available After the London bombings in July 2005, the concern of terrorism scholars and policy makers has turned to “home-grown” terrorism and potential for political violence from within the states. “Radicalization” became a new buzz word. This article follows a number of reviews of the literature on radicalization and offers another angle for looking at this research. First, it discusses the term “radicalization” and suggests the use of the following definition of radicalization as a process by which a person adopts belief systems which justify the use of violence to effect social change and comes to actively support as well as employ violent means for political purposes. Next, it proposes to see the theories of radicalization focusing on the individual and the two dimensions of his/her motivation: whether that motivation is internal or external and whether it is due to personal choice or either internal (due to some psychological traits or external compulsion. Though not all theories fall neatly within these categories, they make it possible to make comparisons of contributions from a variety of different areas thus reflecting on the interdisciplinary nature of the study of terrorism in general and radicalization as a part of it.

  17. Orgasm after radical prostatectomy

    NARCIS (Netherlands)

    Koeman, M; VanDriel, MF; Schultz, WCMW; Mensink, HJA

    Objective To evaluate the ability to obtain and the quality of orgasm after radical prostatectomy, Patients and methods The orgasms experienced after undergoing radical prostatectomy were evaluated in 20 men (median age 65 years, range 56-76) using a semi-structured interview and a self-administered

  18. Radicals in arithmetic

    NARCIS (Netherlands)

    W.J. Palenstijn (Willem Jan)

    2014-01-01

    htmlabstractLet K be a field. A radical is an element of the algebraic closure of K of which a power is contained in K. In this thesis we develop a method for determining what we call entanglement. This describes unexpected additive relations between radicals, and is encoded in an entanglement

  19. Radicals in arithmetic

    NARCIS (Netherlands)

    Palenstijn, Willem Jan

    2014-01-01

    Let K be a field. A radical is an element of the algebraic closure of K of which a power is contained in K. In this thesis we develop a method for determining what we call entanglement. This describes unexpected additive relations between radicals, and is encoded in an entanglement group. We give

  20. Muonium and muonic radicals

    International Nuclear Information System (INIS)

    Burkhard, P.; Fischer, H.; Roduner, E.; Strub, W.; Geeson, D.; Symons, M.C.R.

    1985-01-01

    An energetic positive muon which is injected in a liquid sample of substrate molecules (S) creates an ionization track consisting of substrate cations (S + ) and electrons. Near the end of this track the muon may combine with an electron to form muonium (Mu) which is observable in inert liquids, but which reacts by addition to form a radical. Alternatively, the electron can add to S to form S - , which then combines with the muon to form the radical. Furthermore, instead of ending up in Mu or in a radical the muon may stay in a diamagnetic environment as a solvated muon, or as a muon substituting a proton in a molecule. Of interest in these schemes are the mechanisms and rates of formation of muonated radicals and in particular the rate constants for their reactions to products. Investigations are based on the observation of Mu and the radical by means of the μSR technique in transverse magnetic fields. (Auth.)

  1. Phenolic composition and free radical scavenging activity of different apple varieties in relation to the cultivar, tissue type and storage.

    Science.gov (United States)

    Carbone, K; Giannini, B; Picchi, V; Lo Scalzo, R; Cecchini, F

    2011-07-15

    The aim of this research was to evaluate the influence of genotype, tissue type and cold storage on the bioactive compounds content and on the antiradical activity (AA) of different apple cultivars (Golden cl. B, Fuji cl. Kiku8, Braeburn cl. Hillwell). The content of analysed phyto-compounds depended on the clone, on the part of fruit, and to a minor extent, on the storage. For EC(50) data, the cultivar represented the main source of variation and the interaction with the type of tissue, was significant. The AA of apples, measured by means of the DPPH test, was highly correlated to the flavan-3-ols content, which represents a good predictor of the apple antiradical power. The new Braeburn's clone, the Hillwell, had the worst AA related to a minor phyto-chemical content. Also, its phenolic content was dramatically reduced after cold storage (flesh: -50%; peels: -20%; papples, which is important to improve their quality and consumption benefits, suggesting to the breeders to pay more attention to the potential healthy compounds in the development of new hybrids. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Antrodia camphorata Potentiates Neuroprotection against Cerebral Ischemia in Rats via Downregulation of iNOS/HO-1/Bax and Activated Caspase-3 and Inhibition of Hydroxyl Radical Formation

    Directory of Open Access Journals (Sweden)

    Po-Sheng Yang

    2015-01-01

    Full Text Available Antrodia camphorata (A. camphorata is a fungus generally used in Chinese folk medicine for treatment of viral hepatitis and cancer. Our previous study found A. camphorata has neuroprotective properties and could reduce stroke injury in cerebral ischemia animal models. In this study, we sought to investigate the molecular mechanisms of neuroprotective effects of A. camphorata in middle cerebral artery occlusion (MCAO rats. A selective occlusion of the middle cerebral artery (MCA with whole blood clots was used to induce ischemic stroke in rats and they were orally treated with A. camphorata (0.25 and 0.75 g/kg/day alone or combined with aspirin (5 mg/kg/day. To provide insight into the functions of A. camphorata mediated neuroprotection, the expression of Bax, inducible nitric oxide synthase (iNOS, haem oxygenase-1 (HO-1, and activated caspase-3 was determined by Western blot assay. Treatment of aspirin alone significantly reduced the expressions of HO-1 (P<0.001, iNOS (P<0.001, and Bax (P<0.01 in ischemic regions. The reduction of these expressions was more potentiated when rats treated by aspirin combined with A. camphorata (0.75 g/kg/day. Combination treatment also reduced apoptosis as measured by a significant reduction in active caspase-3 expression in the ischemic brain compared to MCAO group (P<0.01. Moreover, treatment of A. camphorata significantly (P<0.05 reduced fenton reaction-induced hydroxyl radical (OH• formation at a dose of 40 mg/mL. Taken together, A. camphorata has shown neuroprotective effects in embolic rats, and the molecular mechanisms may correlate with the downregulation of Bax, iNOS, HO-1, and activated caspase-3 and the inhibition of OH• signals.

  3. Free radical scavenging capacity and antioxidant activity of methanolic and ethanolic extracts of plum (Prunus domestica L. in both fresh and dried samples

    Directory of Open Access Journals (Sweden)

    Amin Morabbi Najafabad

    2014-09-01

    Full Text Available Objectives: Consumption of fruits, such as plums and prunes, is useful in treating blood circulation disorder, measles, digestive disorder, and prevention of cancer, diabetes, and obesity. The paper presents a description of antioxidant and antiradical capacity of plum (Prunus domestica L. in both fresh and dried samples. Materials and Methods: Samples were mixed with methanol and ethanol (as solvents and were extracted on magnetic shaker, separately. The experiments were carried out to measure the Total Phenolic Content (TPC, Total Flavonoid Content (TFC, Total Antioxidant Capacity (TAC, Reducing Power Assay (RPA, Chain Breaking Activity (CBA, and quantity of Malondialdehyde (MDA, 2,2-Diphenyl-1-Picrylhydrazyl (DPPH,Nitric Oxide (NO,Hydrogen peroxide (H2O2 and superoxide(O2- radicals inhibition. Results: The results showed that the highest values for the TPC, TFC,TAC, RPA, CBA, DPPH, and NO were related to ethanolic extractsof dried sample which showed statistically significant differences (p2O2 and O2-were related to ethanolic extracts of fresh sample. The correlations data were analyzed among all parameters and the TPC and TFC had a significant correlation (r2=0.977. Moreover, it was found that methanol was more successful in extraction procedure than ethanol (p

  4. Metabolic profiling and predicting the free radical scavenging activity of guava (Psidium guajava L.) leaves according to harvest time by 1H-nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Kim, So-Hyun; Cho, Somi K; Hyun, Sun-Hee; Park, Hae-Eun; Kim, Young-Suk; Choi, Hyung-Kyoon

    2011-01-01

    Guava leaves were classified and the free radical scavenging activity (FRSA) evaluated according to different harvest times by using the (1)H-NMR-based metabolomic technique. A principal component analysis (PCA) of (1)H-NMR data from the guava leaves provided clear clusters according to the harvesting time. A partial least squares (PLS) analysis indicated a correlation between the metabolic profile and FRSA. FRSA levels of the guava leaves harvested during May and August were high, and those leaves contained higher amounts of 3-hydroxybutyric acid, acetic acid, glutamic acid, asparagine, citric acid, malonic acid, trans-aconitic acid, ascorbic acid, maleic acid, cis-aconitic acid, epicatechin, protocatechuic acid, and xanthine than the leaves harvested during October and December. Epicatechin and protocatechuic acid among those compounds seem to have enhanced FRSA of the guava leaf samples harvested in May and August. A PLS regression model was established to predict guava leaf FRSA at different harvesting times by using a (1)H-NMR data set. The predictability of the PLS model was then tested by internal and external validation. The results of this study indicate that (1)H-NMR-based metabolomic data could usefully characterize guava leaves according to their time of harvesting.

  5. Free radical reactions of daunorubicin

    International Nuclear Information System (INIS)

    Houee-Levin, C.

    1991-01-01

    Daunorubicin is an antitumor antibiotic activated in vivo by reduction. Its mechanism of action involves DNA and topoisomerase attack, but side effects are cytotoxicity related to free radical formation. Therefore the mechanism of the one-electron reduction of the drug and the reactions of the daunorubicin transients towards compounds of biological interest have been studied by the methods of radiolysis, in order to provide possible explanations of the drug mechanism of action. Their relative importance in cellular conditions is discussed [fr

  6. Inhibition of 2-Amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) Formation by Alkoxy Radical Scavenging of Flavonoids and Their Quantitative Structure-Activity Relationship in a Model System.

    Science.gov (United States)

    Yu, Chundi; Shao, Zeping; Liu, Bing; Zhang, Yan; Wang, Shuo

    2016-08-01

    The inhibitory effect of 10 flavonoids on the formation of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in a creatinine-phenylalanine model system was investigated through electronic spin resonance and a quantitative structure-activity relationship. Alkoxy radicals were observed during the heating process, providing evidence for a radical pathway in the formation of PhIP. The alkoxy radical scavenging capability of the flavonoids was proportional to their inhibition of PhIP formation (IC50 ). We deduced that flavonoid inhibition of PhIP generation occurs via scavenging of alkoxy radicals during the heating process. Multiple linear regression and partial least squares models were used to elucidate the relationship between PhIP inhibition activity and structure characteristics of the flavonoids. The lipo-hydro partition coefficient and molecular fractional polar surface area of the flavonoids were found to be predictive of the inhibition effect. © 2016 Institute of Food Technologists®

  7. Salvage robotic radical prostatectomy

    Directory of Open Access Journals (Sweden)

    Samuel D Kaffenberger

    2014-01-01

    Full Text Available Failure of non-surgical primary treatment for localized prostate cancer is a common occurrence, with rates of disease recurrence ranging from 20% to 60%. In a large proportion of patients, disease recurrence is clinically localized and therefore potentially curable. Unfortunately, due to the complex and potentially morbid nature of salvage treatment, radical salvage surgery is uncommonly performed. In an attempt to decrease the morbidity of salvage therapy without sacrificing oncologic efficacy, a number of experienced centers have utilized robotic assistance to perform minimally invasive salvage radical prostatectomy. Herein, we critically evaluate the existing literature on salvage robotic radical prostatectomy with a focus on patient selection, perioperative complications and functional and early oncologic outcomes. These results are compared with contemporary and historical open salvage radical prostatectomy series and supplemented with insights we have gained from our experience with salvage robotic radical prostatectomy. The body of evidence by which conclusions regarding the efficacy and safety of robotic salvage radical prostatectomy can be drawn comprises fewer than 200 patients with limited follow-up. Preliminary results are promising and some outcomes have been favorable when compared with contemporary open salvage prostatectomy series. Advantages of the robotic platform in the performance of salvage radical prostatectomy include decreased blood loss, short length of stay and improved visualization. Greater experience is required to confirm the long-term oncologic efficacy and functional outcomes as well as the generalizability of results achieved at experienced centers.

  8. A Direct in Vivo Comparison of the Melanocortin Monovalent Agonist Ac-His-DPhe-Arg-Trp-NH2 versus the Bivalent Agonist Ac-His-DPhe-Arg-Trp-PEDG20-His-DPhe-Arg-Trp-NH2: A Bivalent Advantage.

    Science.gov (United States)

    Lensing, Cody J; Adank, Danielle N; Wilber, Stacey L; Freeman, Katie T; Schnell, Sathya M; Speth, Robert C; Zarth, Adam T; Haskell-Luevano, Carrie

    2017-06-21

    Bivalent ligands targeting putative melanocortin receptor dimers have been developed and characterized in vitro; however, studies of their functional in vivo effects have been limited. The current report compares the effects of homobivalent ligand CJL-1-87, Ac-His-DPhe-Arg-Trp-PEDG20-His-DPhe-Arg-Trp-NH 2 , to monovalent ligand CJL-1-14, Ac-His-DPhe-Arg-Trp-NH 2 , on energy homeostasis in mice after central intracerebroventricular (ICV) administration into the lateral ventricle of the brain. Bivalent ligand CJL-1-87 had noteworthy advantages as an antiobesity probe over CJL-1-14 in a fasting-refeeding in vivo paradigm. Treatment with CJL-1-87 significantly decreased food intake compared to CJL-1-14 or saline (50% less intake 2-8 h after treatment). Furthermore, CJL-1-87 treatment decreased the respiratory exchange ratio (RER) without changing the energy expenditure indicating that fats were being burned as the primary fuel source. Additionally, CJL-1-87 treatment significantly lowered body fat mass percentage 6 h after administration (p < 0.05) without changing the lean mass percentage. The bivalent ligand significantly decreased insulin, C-peptide, leptin, GIP, and resistin plasma levels compared to levels after CJL-1-14 or saline treatments. Alternatively, ghrelin plasma levels were significantly increased. Serum stability of CJL-1-87 and CJL-1-14 (T 1/2 = 6.0 and 16.8 h, respectively) was sufficient to permit physiological effects. The differences in binding affinity of CJL-1-14 compared to CJL-1-87 are speculated as a possible mechanism for the bivalent ligand's unique effects. We also provide in vitro evidence for the formation of a MC3R-MC4R heterodimer complex, for the first time to our knowledge, that may be an unexploited neuronal molecular target. Regardless of the exact mechanism, the advantageous ability of CJL-1-87 compared to CJL-1-14 to increase in vitro binding affinity, increase the duration of action in spite of decreased serum stability, decrease

  9. Gnosticism and Radical Feminism

    DEFF Research Database (Denmark)

    Cahana, Jonathan

    2016-01-01

    and radical feminism would easily fall under this definition. There is, however, one major difference: since radical feminism is a relatively recent phenomenon which also benefited from modern modes of text production and preservation, almost all of the sources are still with us. This, in turn, may allow us...... to use radical feminism to make certain aspects of ancient Gnosticism re-emerge from their long submersion, provided that enough similarities can be independently drawn between the two phenomena to merit such a comparison. This paper therefore presents a comparison between concepts and positions...

  10. Homegrown religious radicalization

    DEFF Research Database (Denmark)

    Khawaja, Iram

    It has been reported that a growing number of youngsters from Western Europe are engaging in conflicts motivated by religious and political conflicts in the Middle East. This paper explores the reasons behind this seemingly religious radicalization from the point of view of the youngsters...... youngsters and parents of youngsters who have chosen a radicalized path in life. The paper will shed light on how the sense of and yearning for belonging and recognition have to be taken into account in our understanding of homegrown religious radicalization...

  11. Radical's view of sciences

    International Nuclear Information System (INIS)

    Mittal, J.P.

    2004-01-01

    Full text: General concept in radiation biology is that free radicals are highly reactive and they can damage vital cellular molecules leading to injurious effects. However, in this talk, evidence will be presented through the techniques of electron paramagnetic resonance ( EPR ) and pulse radiolysis that free radicals can be highly selective in their reaction with the target molecules. In addition, attempts will be made to present a brief account of emerging scenario of free radical generation, identification and their involvement in radiation damage mechanisms in chemical and biological systems

  12. Separation of photo-induced radical pair in cryptochrome to a functionally critical distance

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Domratcheva, Tatiana; Schulten, Klaus

    2014-01-01

    Cryptochrome is a blue light receptor that acts as a sensor for the geomagnetic field and assists many animals in long-range navigation. The magnetoreceptor function arises from light-induced formation of a radical pair through electron transfer between a flavin cofactor (FAD) and a triad...... of tryptophan residues. Here, this electron transfer is investigated by quantum chemical and classical molecular dynamics calculations. The results reveal how sequential electron transfer, assisted by rearrangement of polar side groups in the cryptochrome interior, can yield a FAD-Trp radical pair state...... step can overcome in speed both recombination (electron back-transfer) and proton transfer involving the radical pair reached after primary electron transfer....

  13. Development and installation of solution measurement and monitoring system (SMMS) at TRP

    International Nuclear Information System (INIS)

    Satoh, Takehiko; Yamanaka, Atsushi; Kashimura, Takao; Yamamoto, Tokuhiro

    2001-01-01

    The IAEA proposed TRP safeguard improvement plants in 1995 for closer and more efficient safeguards of TRP. Development of Solution Measurement and Monitoring System (SMMS) is one item of the plans and has been carried out under the JASPAS program as JA-6. Following to the IAEA's acceptance test, after the installation of the SMMS in 1999, field test of this system has been carried out. The main purpose of the SMMS is to establish the IAEA's independent monitoring system. Besides input and output accountability tanks, seven Pu storage tanks and a pot attached to the Pu storage tanks are monitored continuously, and solution level, density and temperature data of these tanks are recorded by the SMMS. Authentication of the SMMS, confirmed by the IAEA at the acceptance test, is kept by failure detection and recording functions of the system. (author)

  14. Properties of the intracellular transient receptor potential (TRP) channel in yeast, Yvc1.

    Science.gov (United States)

    Chang, Yiming; Schlenstedt, Gabriel; Flockerzi, Veit; Beck, Andreas

    2010-05-17

    Transient receptor potential (TRP) channels are found among mammals, flies, worms, ciliates, Chlamydomonas, and yeast but are absent in plants. These channels are believed to be tetramers of proteins containing six transmembrane domains (TMs). Their primary structures are diverse with sequence similarities only in some short amino acid sequence motifs mainly within sequences covering TM5, TM6, and adjacent domains. In the yeast genome, there is one gene encoding a TRP-like sequence. This protein forms an ion channel in the vacuolar membrane and is therefore called Yvc1 for yeast vacuolar conductance 1. In the following we summarize its prominent features. Copyright 2009 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  15. Discovery of melanocortin ligands via a double simultaneous substitution strategy based on the Ac-His-DPhe-Arg-Trp-NH2 template.

    Science.gov (United States)

    Todorovic, Aleksandar; Lensing, Cody J; Holder, Jerry Ryan; Scott, Joseph W; Sorensen, Nicholas B; Haskell-Luevano, Carrie

    2018-05-21

    The melanocortin system regulates an array of diverse physiological functions including pigmentation, feeding behavior, energy homeostasis, cardiovascular regulation, sexual function, and steroidogenesis. Endogenous melanocortin agonist ligands all possess the minimal messaging tetrapeptide sequence His-Phe-Arg-Trp. Based on this endogenous sequence, the Ac-His1-DPhe2-Arg3-Trp4-NH 2 tetrapeptide has previously been shown to be a useful scaffold when utilizing traditional positional scanning approaches to modify activity at the various melanocortin receptors (MC1-5R). The study reported herein was undertaken to evaluate a double simultaneous substitution strategy as an approach to further diversify the Ac-His1-DPhe2-Arg3-Trp4-NH 2 tetrapeptide with concurrent introduction of natural and unnatural amino acids at positions 1, 2, or 4 as well as an octanoyl residue at the N-terminus. The designed library includes the following combinations: (A) double simultaneous substitution at capping group position (Ac) together with position 1, 2, or 4, (B) double simultaneous substitution at position 1 and 2, (C) double simultaneous substitution at position 1 and 4, and (D) double simultaneous substitution at position 2 and 4. Several lead ligands with unique pharmacologies were discovered in the current study including antagonists targeting the neuronal mMC3R with minimal agonist activity and ligands with selective profiles for the various melanocortin subtypes. The results suggest that the double simultaneous substitution strategy is a suitable approach in altering melanocortin receptor potency, selectivity, or converting agonists into antagonists and vice versa.

  16. TRP and ASIC channels mediate the antinociceptive effect of citronellyl acetate.

    Science.gov (United States)

    Rios, Emiliano Ricardo Vasconcelos; Rocha, Nayrton Flávio Moura; Carvalho, Alyne Mara Rodrigues; Vasconcelos, Leonardo Freire; Dias, Marília Leite; de Sousa, Damião Pergentino; de Sousa, Francisca Cléa Florenço; Fonteles, Marta Maria de França

    2013-05-25

    Citronellyl acetate (CAT), a monoterpene product of the secondary metabolism of plants, has been shown in the literature to possess several different biological activities. However, no antinociceptive abilities have yet been discussed. Here, we used acute pain animal models to describe the antinociceptive action of CAT. The acetic acid-induced writhing test and the paw-licking test, in which paw licking was induced by glutamate and formalin, were performed to evaluate the antinociceptive action of CAT and to determine the involvement of PKC, PKA, TRPV1, TRPA1, TRPM8 and ASIC in its antinociceptive mechanism. To do so, we induced paw-linking using agonists. CAT was administered intragastrically (25, 50, 75, 100 and 200 mg/kg), and the two higher doses caused antinociceptive effects in the acetic acid model; the highest dose reduced pain for 4h after it was administered (200 mg/kg). In the formalin test, two doses of CAT promoted antinociception in both the early and later phases of the test. The glutamate test showed that its receptors are involved in the antinociceptive mechanism of CAT. Pretreatment with CAT did not alter locomotor activity or motor coordination. In an investigation into the participation of TRP channels and ASICs in CAT's antinociceptive mechanism, we used capsaicin (2.2 μg/paw), cinnamaldehyde (10 mmol/paw), menthol (1.2 mmol/paw) and acidified saline (2% acetic acid, pH 1.98). The results showed that TRPV1, TRPM8 and ASIC, but not TRPA1, are involved in the antinociceptive mechanism. Finally, the involvement of PKC and PKA was also studied, and we showed that both play a role in the antinociceptive mechanism of CAT. The results of this work contribute information regarding the antinociceptive properties of CAT on acute pain and show that, at least in part, TRPV1, TRPM8, ASIC, glutamate receptors, PKC and PKA participate in CAT's antinociceptive mechanism. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  17. Moderate and Radical Islam

    National Research Council Canada - National Science Library

    Rabasa, Angel

    2005-01-01

    This report presents the statement of Angel Rabasa, PhD, Senior Policy Analyst, The RAND Corporation, to the Committee on Armed Services, Defense Review Terrorism and Radical Islam Gap Panel, United...

  18. Superb hydroxyl radical-mediated biocidal effect induced antibacterial activity of tuned ZnO/chitosan type II heterostructure under dark

    International Nuclear Information System (INIS)

    Podder, Soumik; Halder, Suman; Roychowdhury, Anirban; Das, Dipankar; Ghosh, Chandan Kr.

    2016-01-01

    Reactive oxygen species (ROS) is the most dominating factor for bacteria cell toxicity due to release of oxidative stress. Hydroxyl radical ("·OH) is a strong oxidizing ROS that has high impact on biocidal activity. This present paper highlights "·OH influenced antibacterial activity and biocidal propensity of tuned ZnO/chitosan (ZnO/CS) nanocomposite against Pseudomonas putida (P. putida) in the absence of light for the first time. For this purpose, the CS proportion was increased by 25 % (w/w) of ZnO during the preparation of ZnO/CS nanocomposite and a systematic study of different ROS like superoxide anion (O_2"·"−), hydrogen peroxide (H_2O_2) and "·OH production as well as their kinetics was carried out both under UV irradiation and in dark by UV–Vis spectroscopy using NBT dye, starch and iodine reaction and fluorescence spectroscopy using terephthalic acid. The decoration of ZnO nanoparticles (ZnO·NPs) with CS tuning was characterized by XRD and FTIR spectroscopy, revealing sustained crystallinity and surface coating of ZnO NP (size about ~24 nm) by CS molecule. The hybridization of ZnO nanoparticles with CS@50 wt% (w/w) resulted superior biocidal activity (81 %) within 3 h in dark mediated by optimum production of "·OH among all ROS. Here we have proposed the enhanced production of "·OH in ZnO/CS due to generation of holes by entrapment of electrons in acceptor level formed in nanocomposite for the first time, and the acceptor levels were probed by Positron annihilation lifetime spectroscopy. The increase in non-positronium (non-Ps) formation probability (I_2) in ZnO/CS nanocomposite confirmed the acceptor levels. This work also confirms surface defect-mediated ROS generation in dark, and zinc interstitials are proposed as active defect sites for generation of holes and "·OH for the first time and confirmed by steady-state room temperature photoluminescence spectroscopy. Finally, a plausible mechanism was hypothesized focusing on hole

  19. Superb hydroxyl radical-mediated biocidal effect induced antibacterial activity of tuned ZnO/chitosan type II heterostructure under dark

    Science.gov (United States)

    Podder, Soumik; Halder, Suman; Roychowdhury, Anirban; Das, Dipankar; Ghosh, Chandan Kr.

    2016-10-01

    Reactive oxygen species (ROS) is the most dominating factor for bacteria cell toxicity due to release of oxidative stress. Hydroxyl radical (·OH) is a strong oxidizing ROS that has high impact on biocidal activity. This present paper highlights ·OH influenced antibacterial activity and biocidal propensity of tuned ZnO/chitosan (ZnO/CS) nanocomposite against Pseudomonas putida (P. putida) in the absence of light for the first time. For this purpose, the CS proportion was increased by 25 % (w/w) of ZnO during the preparation of ZnO/CS nanocomposite and a systematic study of different ROS like superoxide anion (O 2 ·- ), hydrogen peroxide (H2O2) and ·OH production as well as their kinetics was carried out both under UV irradiation and in dark by UV-Vis spectroscopy using NBT dye, starch and iodine reaction and fluorescence spectroscopy using terephthalic acid. The decoration of ZnO nanoparticles (ZnO·NPs) with CS tuning was characterized by XRD and FTIR spectroscopy, revealing sustained crystallinity and surface coating of ZnO NP (size about 24 nm) by CS molecule. The hybridization of ZnO nanoparticles with CS@50 wt% (w/w) resulted superior biocidal activity (81 %) within 3 h in dark mediated by optimum production of ·OH among all ROS. Here we have proposed the enhanced production of ·OH in ZnO/CS due to generation of holes by entrapment of electrons in acceptor level formed in nanocomposite for the first time, and the acceptor levels were probed by Positron annihilation lifetime spectroscopy. The increase in non-positronium (non-Ps) formation probability (I2) in ZnO/CS nanocomposite confirmed the acceptor levels. This work also confirms surface defect-mediated ROS generation in dark, and zinc interstitials are proposed as active defect sites for generation of holes and ·OH for the first time and confirmed by steady-state room temperature photoluminescence spectroscopy. Finally, a plausible mechanism was hypothesized focusing on hole generation in ZnO NP and

  20. Superb hydroxyl radical-mediated biocidal effect induced antibacterial activity of tuned ZnO/chitosan type II heterostructure under dark

    Energy Technology Data Exchange (ETDEWEB)

    Podder, Soumik [Jadavpur University, School of Materials Science and Nanotechnology (India); Halder, Suman [Jadavpur University, Department of Pharmaceutical Technology (India); Roychowdhury, Anirban; Das, Dipankar [Kolkata Centre, UGC-DAE Consortium for Scientific Research (India); Ghosh, Chandan Kr., E-mail: chandu-ju@yahoo.co.in [Jadavpur University, School of Materials Science and Nanotechnology (India)

    2016-10-15

    Reactive oxygen species (ROS) is the most dominating factor for bacteria cell toxicity due to release of oxidative stress. Hydroxyl radical ({sup ·}OH) is a strong oxidizing ROS that has high impact on biocidal activity. This present paper highlights {sup ·}OH influenced antibacterial activity and biocidal propensity of tuned ZnO/chitosan (ZnO/CS) nanocomposite against Pseudomonas putida (P. putida) in the absence of light for the first time. For this purpose, the CS proportion was increased by 25 % (w/w) of ZnO during the preparation of ZnO/CS nanocomposite and a systematic study of different ROS like superoxi