Browsing by Author "Letelier Muñoz, María Eugenia"

Now showing items 1-17 of 17

    • Antioxidant effects of 1,4-dihydropyridine and nitroso aryl derivatives on the Fe+3/ascorbate-stimulated ... 
      Díaz Araya, Guillermo; Godoy Oviedo, Luis; Naranjo, Luis; Squella Serrano, Juan; Letelier Muñoz, María Eugenia; Núñez Vergara, Luis (PERGAMON-ELSEVIER SCIENCE, 1998-09)
      1. Lipid peroxidation in rat brain slices was induced by Fe+3/ascorbate. 2. Brain lipid peroxidation, as measured by malondialdehyde formation, was inhibited by all the tested nitro aryl 1,4-dihydropyridine derivatives ...
    • ANTIOXIDANT PROPERTIES OF Rosmarinus officinalis AND ITS EFFECTS ON XENOBIOTIC BIOTRANSFORMATION 
      Letelier Muñoz, María Eugenia; Terán, A.; Barra, M. A.; Aracena Parks, Paula (Jose L. Martinez, 2009-11-30)
      Rosmarinus officinalis (rosemary) extracts display antioxidant properties mainly due to the presence of polyphenols. These properties have yet to be systematically studied in biological systems. In this study, we used rat ...
    • Chronic exposure of HepG2 cells to excess copper results in depletion of glutathione and induction of ... 
      Jiménez T., Inés; Aracena Stiven, Paula; Letelier Muñoz, María Eugenia; Navarro, P.; Speisky Cosoy, Hernán (PERGAMON-ELSEVIER SCIENCE LTD, 2002-04)
      Metallothionein (MT) and reduced glutathione (GSH) play an important role in the intracellular handling of copper by preventing the generation and favouring the removal of copper-derived free radicals. The present study ...
    • Copper modifies liver microsomal UDP-glucuronyltransferase activity through different and opposite mechanisms 
      Letelier Muñoz, María Eugenia; Lagos, Fernando; Faúndez, Mario; Miranda, Dante; Montoya, Margarita; Aracena Parks, Paula; González Lira, Víctor (ELSEVIER IRELAND LTD, 2007-04)
      Treatment of hepatic microsomes with Fe3+/ascorbate activates UDP-glucuronyltransferase (UGT), a phenomenon totally prevented and reversed by reducing agents. At #2;M concentrations, iron and copper ions catalyze the ...
    • DPPH and oxygen free radicals as pro-oxidant of biomolecules 
      Letelier Muñoz, María Eugenia; Molina Berríos, Alfredo Enrique; Cortés Troncoso, Juan; Jara Sandoval, José; Holst, Marianne; Palma, Karina; Montoya, Margarita; Miranda, Dante; González Lira, Víctor (PERGAMON-ELSEVIER SCIENCE LTD, 2008-03)
      Numerous investigations exist about the alterations that oxygen free radicals can provoke on biomolecules; these modifications can be prevented and/or reversed by different antioxidants agents. On the other hand, ...
    • Inhibition of cytosolic glutathione S-transferase activity from rat liver by copper 
      Letelier Muñoz, María Eugenia; Martínez, M.; González Lira, Víctor; Faúndez, Mario; Aracena Parks, Paula (ELSEVIER, 2006-12-01)
      H2O2 inactivation of particular GST isoforms has been reported, with no information regarding the overall effect of other ROS on cytosolic GST activity. The present work describes the inactivation of total cytosolic GST ...
    • Isradipine and lacidipine: Effects in vivo and in vitro on Trypanosoma cruzi epimastigotes 
      Núñez Vergara, Luis; Squella Serrano, Juan; Bollo Dragnic, Soledad; Marín Catalán, Rigoberto; Pino, L.; Díaz Araya, Guillermo; Letelier Muñoz, María Eugenia (PERGAMON-ELSEVIER SCIENCE LTD, 1998-01)
      1. Isradipine and lacidipine, two new drugs that are members of the nitro-aryl-1,4-dihydropyridine family, produced inhibition of both growth cultures and oxygen consumption on epimastigotes of Trypanosoma cruzi Tulahuen ...
    • Liver microsomal biotransformation of nitro-aryl drugs: Mechanism for potential oxidative stress induction 
      Letelier Muñoz, María Eugenia; Izquierdo Lazo, Pamela Alejandra; Godoy Oviedo, Luis; Lepe Agrodnik, Ana María; Faúndez Cáceres, Mario Antonio (JOHN WILEY & SONS LTD, 2004-11)
      Toxic effects of several nitro-aryl drugs are attributed to the nitro-reduction that may be suffered in vivo, a reaction that may be catalysed by different reductases. One of these enzymes is NADPH-cytochrome P450 reductase, ...
    • Microsomal oxidative damage promoted by acetaminophen metabolism 
      Letelier Muñoz, María Eugenia; López Valladares, Miguel; Peredo Silva, Liliana; Rojas Sepúlveda, Daniel; Aracena, Paula (PERGAMON-ELSEVIER SCIENCE LTD., 2011-10)
      Adverse reactions of acetaminophen have been associated to oxidative stress, which may be elicited by reactive oxygen species (ROS) and/or production of the metabolite NAPQI. Both phenomena would arise through the activity ...
    • Microsomal UDP-glucuronyltransferase in rat liver: Oxidative activation 
      Letelier Muñoz, María Eugenia; Pimentel Miranda, Alejandra Patricia; Pino, Patricia; Lepe Agrodnik, Ana María; Faúndez Cáceres, Mario Antonio; Aracena Parks, Paula; Speisky Cosoy, Hernán (BLACKWELL PUBLISHING, 2005-06)
      Activation of microsomal UDP-glucuronyltransferase (UDPGT) activity by treatment of hepatic microsomes with either detergents or Fe3+/ascorbate pro-oxidant system has been reported; however, definite mechanisms underlying ...
    • Nitro radical anion formation from nifurtimox II: electrochemical evidence 
      Núñez Vergara, Luis; Aldunate, Jorge; Letelier Muñoz, María Eugenia; Bollo Dragnic, Soledad; Repetto Scaramelli, Yolanda; Morello Casté, Antonio; Spencer, P. L.; Squella Serrano, Juan (Elsevier, 1995)
      The cyclic voltammetric (CV) behaviour of nifurtimox was studied. The addition of aprotic solvent (DMF) to nifurtimox in an aqueous citrate buffer system was examined. Qualitatively this results in separation of the initial ...
    • Nitroaryl-1,4-dihydropyridines as antioxidants against rat liver microsomes oxidation induced by iron/ascorbate, ... 
      Letelier Muñoz, María Eugenia; Entrala Alrruiz, Paz Andrea; López Alarcón, Camilo; González Lira, Víctor; Molina Berríos, Alfredo Enrique; Cortés Troncoso, Juan; Jara Sandoval, José; Santander, P.; Núñez Vergara, Luis (PERGAMON-ELSEVIER SCIENCE, 2007-12)
      1,4-Dihydropyridines (DHPs) used in the treatment of cardiovascular diseases, are calcium channel antagonists and also antioxidant agents. These drugs are metabolized through cytochrome P-450 oxidative system, majority ...
    • Possible mechanisms underlying copper-induced damage in biological membranes leading to cellular toxicity 
      Letelier Muñoz, María Eugenia; Lepe, Ana María; Faúndez, Mario; Salazar, Julia; Marín Catalán, Rigoberto; Aracena Parks, Paula; Speisky Cosoy, Hernán (ELSEVIER SCI IRELAND, 2005-01-15)
      It is generally accepted that copper toxicity is a consequence of the generation of reactive oxygen species (ROS) by copper ions via Fenton or Haber-Weiss reactions. Copper ions display high affinity for thiol and amino ...
    • Preliminary studies on antioxidant and anti-cataract activities of Cheilanthes glauca (Cav.) Mett. through ... 
      Pastene, Edgar; Avello, Marcia; Letelier Muñoz, María Eugenia; Sanzana, Elizabeth; Vega, Mario; González, Margarita (The MathWorks Automotive Advisory Board, 2007)
      Aqueous extracts of Cheilanthes glauca (Cav.) Mett., (Adiantaceae), commonly named Doradilla, are often used in folk medicine as anti-inflammatory and for diabetes treatment. In the present study the antioxidant capacity ...
    • A protocol for evaluating the safety of herbal preparations in a rat model: the case of a supercritical ... 
      Letelier Muñoz, María Eugenia; Aracena Parks, Paula; Peredo Silva, Liliana (2010)
      Herbal extracts must be evaluated for their efficacy and safety. In vivo acute toxicity studies must consider the different mechanisms by which active compounds may elicit toxicological outcomes. Thus, a methodology to ...
    • Surfactant and antioxidant properties of an extract from Chenopodium quinoa Willd seed coats 
      Letelier Muñoz, María Eugenia; Rodríguez Rojas, Carmen; Sánchez Jofré, Sebastián; Aracena Parks, Paula (ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2011-03)
      Chenopodium quinoa Willd (quinoa) has been a source of food for millennia by the Andes region native population. Because of its bitter taste, quinoa seeds are commercialized without their coat for human consumption. Quinoa ...
    • Topical anti-inflammatory activity of 2 alpha-hydroxy pentacyclic triterpene acids from the leaves of Ugni molinae 
      Aguirre, María C.; Delporte Vergara, Carla; Backhouse Erazo, Nadine; Erazo, Silvia; Letelier Muñoz, María Eugenia; Cassels Niven, Bruce; Silva, Ximena; Alegría, Sergio; Negrete Córdova, Rosa (PERGAMON-ELSEVIER SCIENCE LTD, 2006-08-15)
      Leaf extracts of Ugni molinae Turcz. are used in the Chilean cosmetic industry on the assumption that they have decongestant, regenerative, and anti-aging properties. A bioassay-guided fractionation of this plant material ...