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edgar pastene

Laura D Delgado, Paz E Zúñiga, Nicolás E Figueroa, Edgar Pastene, Hugo F Escobar-Sepúlveda, Pablo M Figueroa, Adrián Garrido-Bigotes, Carlos R Figueroa
Fleshy fruits are an important source of anthocyanins and proanthocyanidins (PAs), which protect plants against stress, and their consumption provides beneficial effects for human health. In strawberry fruit, the application of exogenous methyl jasmonate (MeJA) upregulates anthocyanin accumulation, although the relationship between the jasmonate pathway and anthocyanin and PA biosynthesis in fruits remains to be understood. Anthocyanin and PA accumulation is mainly regulated at the transcriptional level through R2R3-MYB and bHLH transcription factors in different plant species and organs...
June 13, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Vania Sáez, Edgar Pastene, Carola Vergara, Claudia Mardones, Isidro Hermosín-Gutiérrez, Sergio Gómez-Alonso, M Victoria Gómez, Cristina Theoduloz, Sebastián Riquelme, Dietrich von Baer
The following oligostilbenoids were isolated from extracts of Vitis vinifera L. Pinot Noir grape canes produced at a pilot-plant scale: (E)-ε-viniferin, (E)-resveratrol, (E)-piceatannol, ampelopsin A, vitisin B, pallidol, (E)-δ-viniferin, (E)-ω-viniferin, (E)-trans-cis-miyabenol C, isorhapontigenin, scirpusin A, and a new isomer named isoscirpusin A. The antioxidant capacity of the isolated stilbenoids was studied by three different assays, and their 50% inhibition concentration (IC50 ) against cancer cells was determined by MTT reduction assay...
November 1, 2018: Food Chemistry
Mireille Andriamihaja, Annaïg Lan, Martin Beaumont, Marta Grauso, Martin Gotteland, Edgar Pastene, Maria Jose Cires, Catalina Carrasco-Pozo, Daniel Tomé, François Blachier
Hydrogen sulfide (H2 S), a metabolic end product synthesized by the microbiota from L-cysteine, has been shown to act at low micromolar concentration as a mineral oxidative substrate in colonocytes while acting as an inhibitor of oxygen consumption at higher luminal concentrations (65 µM and above). From the previous works showing that polyphenols can bind volatile sulfur compounds, we hypothesized that different dietary proanthocyanidin-containing polyphenol (PACs) plant extracts might modulate the inhibitory effect of H2 S on colonocyte respiration...
June 2018: Amino Acids
Jocelyn Fuentes, Elías Atala, Edgar Pastene, Catalina Carrasco-Pozo, Hernán Speisky
Quercetin oxidation is generally believed to ultimately result in the loss of its antioxidant properties. To test this assertion, quercetin oxidation was induced, and after each of its major metabolites was identified and isolated by HPLC-DAD-ESI-MS/MS, the antioxidant (dichlorodihydrofluorescein oxidation-inhibiting) and cytoprotective (LDH leakage-preventing) properties were evaluated in Hs68 and Caco2 cells exposed to indomethacin. Compared to quercetin, the whole mixture of metabolites (QOX ) displayed a 20-fold greater potency...
December 20, 2017: Journal of Agricultural and Food Chemistry
Luis Bustamante, Diana Cárdenas, Dietrich von Baer, Edgar Pastene, Daniel Duran-Sandoval, Carola Vergara, Claudia Mardones
Miniaturized sample pretreatments for the analysis of phenolic metabolites in plasma, involving protein precipitation, enzymatic deconjugation, extraction procedures, and different derivatization reactions were systematically evaluated. The analyses were conducted by gas chromatography with mass spectrometry for the evaluation of 40 diet-derived phenolic compounds. Enzyme purification was necessary for the phenolic deconjugation before extraction. Trimethylsilanization reagent and two different tetrabutylammonium salts for derivatization reactions were compared...
September 2017: Journal of Separation Science
Marcia Avello L, Edgar Pastene N, Pola Fernández R, Pia Córdova M
Cannabis sativa (marihuana) is considered an illicit drug due to its psychoactive properties. Recently, the Chilean government opened to the use cannabis in the symptomatic treatment of some patients. The biological effects of cannabis render it useful for the complementary treatment of specific clinical situations such as chronic pain. We retrieved scientific information about the analgesic properties of cannabis, using it as a safe drug. The drug may block or inhibit the transmission of nervous impulses at different levels, an effect associated with pain control...
March 2017: Revista Médica de Chile
Marcia Avello, Pola Fernández, Marcos Fernández, Berta Schulz, Marta De Diego, Sigrid Mennickent, Pedro Novoa, Edgar Pastene
INTRODUCTION: Pediculosis capitis is a public health problem with a high prevalence. The emergence of parasite resistance to conventional pediculicide is of great concern worldwide. OBJECTIVE: To develop alternatives pediculicide, effective and safe, based on the essential oil of Eucaliptus globulus. METHOD: Through bioassays active concentrations ranges of the essential oil were established, and proceeded to develop a standardized, stable, pharmaceutical form, evaluating its effects on our population...
August 2016: Revista Chilena de Infectología: órgano Oficial de la Sociedad Chilena de Infectología
Ximena Wong, Catalina Carrasco-Pozo, Elizabeth Escobar, Paola Navarrete, Franςois Blachier, Mireille Andriamihaja, Annaig Lan, Daniel Tomé, Marı́a José Cires, Edgar Pastene, Martin Gotteland
The protective effect of proanthocyanidin-containing polyphenol extracts from apples, avocados, cranberries, grapes, or proanthocyanidin microbial metabolites was evaluated in colonic epithelial cells exposed to p-cresol, a deleterious compound produced by the colonic microbiota from l-tyrosine. In HT29 Glc(-/+) cells, p-cresol significantly increased LDH leakage and decreased ATP contents, whereas in Caco-2 cell monolayers, it significantly decreased the transepithelial electrical resistance and increased the paracellular transport of FITC-dextran...
May 11, 2016: Journal of Agricultural and Food Chemistry
Edgar David González-González, Leobardo Manuel Gómez-Oliván, Marcela Galar-Martínez, Patricia Vieyra-Reyes, Hariz Islas-Flores, Sandra García-Medina, Juan Manuel Jiménez-Vargas, Celene Razo-Estrada, Ricardo Pérez-Pastén
Many toxic xenobiotics that enter the aquatic environment exert their effects through redox cycling. Oxidative stress, which incorporates both oxidative damage and antioxidant defenses, is a common effect induced in organisms exposed to xenobiotics in their environment. The results of the present study aimed to determine the oxidative stress induced in the common carp Cyprinus carpio by contaminants [metals and nonsteroidal anti-inflammatory drugs (NSAIDs)] present in Madín Reservoir. Five sampling stations (SSs), considered to have the most problems due to discharges, were selected...
August 2014: Archives of Environmental Contamination and Toxicology
Edgar Pastene, Víctor Parada, Marcia Avello, Antonieta Ruiz, Apolinaria García
In this work, the anti-Helicobacter pylori effect of an aqueous extract from dried leaves of Peumus boldus Mol. (Monimiaceae) was evaluated. This extract displayed high inhibitory activity against H. pylori urease. Therefore, in order to clarify the type of substances responsible for such effect, a bioassay-guided fractionation strategy was carried out. The active compounds in the fractions were characterized through different chromatographic methods (RP-HPLC; HILIC-HPLC). The fraction named F5 (mDP = 7...
November 2014: Phytotherapy Research: PTR
Catalina Carrasco-Pozo, Edgar Pastene, Carola Vergara, Moises Zapata, Cristian Sandoval, Martin Gotteland
BACKGROUND: The effect of indomethacin (INDO) on Ca(2+) mobilization, cytotoxicity, apoptosis and caspase activation and the potential protective effect of quercetin (QUE), resveratrol (RES) and rutin (RUT) were determined in Caco-2 cells. METHODS: Caco-2 cells were incubated with INDO in the presence or absence of QUE, RES or RUT. The concentrations of Ca(2+) in the cytosol (Fluo-3 AM) and mitochondria (Rhod-2 AM) were determined as well as the cytotoxicity (MTT reduction and LDH leakage), apoptosis (TUNEL) and caspase-3 and 9 activities...
December 2012: Biochimica et Biophysica Acta
Catalina Carrasco-Pozo, Hernán Speisky, Oscar Brunser, Edgar Pastene, Martin Gotteland
The stability of an apple peel polyphenol extract (APPE) with powerful antioxidant activity was evaluated under acidic conditions in vitro, and its protective effect against gastrointestinal damage was investigated in rats treated with indomethacin. The antioxidant activity of APPE remained stable at pH 2.0 for 4 h. In rats treated with indomethacin (40 mg/kg ig), the previous administration of APPE protected the gastric, intestinal, and colonic mucosa from oxidative stress by preventing increased malondialdehyde concentrations and decreasing the GSH/GSSG ratio...
June 22, 2011: Journal of Agricultural and Food Chemistry
Edgar Pastene, Hernán Speisky, Apolinaria García, Jessica Moreno, Miriam Troncoso, Guillermo Figueroa
The inhibitory effects of a standarized apple peel polyphenol-rich extract (APPE) against Helicobacter pylori infection and vacuolating bacterial toxin (VacA) induced vacuolation were investigated. Apple peel polyphenols significantly prevented vacuolation in HeLa cells with an IC(50) value of 390 microg of gallic acid equivalents (GAE)/mL. APPE also displayed an in vitro antiadhesive effect against H. pylori. A significant inhibition was observed with a 20-60% reduction of H. pylori attachment at concentrations between 0...
June 23, 2010: Journal of Agricultural and Food Chemistry
Edgar Pastene, Hernán Speisky, Miriam Troncoso, Julio Alarcón, Guillermo Figueroa
In the present work, the in vitro effect of a standardized extract of apple peel APPE (60% of total polyphenols; 58% of flavonoids; 30% of flavan-3-ols and procyanidins) was evaluated with regard to the viability of Helicobacter pylori. The cytotoxic effect of APPE on H. pylori was also evaluated through the resazurin assay and ATP level determination. In both assays, APPE showed an early cytotoxic effect, which was both concentration and time-dependent. Additionally, the effect of APPE on the intra and extracellular production of reactive oxygen species (ROS) was evaluated in human neutrophils stimulated by H...
September 9, 2009: Journal of Agricultural and Food Chemistry
Edgar Pastene, Miriam Troncoso, Guillermo Figueroa, Julio Alarcón, Hernán Speisky
Apple peel extracts and their fractions pooled according to their molecular size were prepared and evaluated for their inhibitory activity against Helicobacter pylori and Jack bean ureases. Urease Inhibitory effect of apple peel polyphenols (APPE) extracted from the Granny Smith variety was concentration-dependent and reversible. High molecular weight polyphenols (HMW) were more active against Helicobacter pylori and Jack bean ureases than low molecular weight polyphenols with IC50 values of 119 and 800 microg GAE/mL, respectively...
January 28, 2009: Journal of Agricultural and Food Chemistry
Hernán Speisky, Maritza Gómez, Catalina Carrasco-Pozo, Edgar Pastene, Camilo Lopez-Alarcón, Claudio Olea-Azar
Cu(2+) ions and GSH molecules interact swiftly to form the complex Cu(I)-glutathione. We investigated the potential capacity of such complex to reduce molecular oxygen. The addition of SOD to a solution containing Cu(I)-glutathione led to a sustained decline of the basal oxygen level. Such effect was partially reverted by the addition of catalase. The complex was able to induce the reduction of cytochrome c and the oxidation of dyhydroethidium into 2-hydroxyethidium. Both effects were totally blocked by SOD...
July 1, 2008: Bioorganic & Medicinal Chemistry
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