Examinando por Autor "Adrián Paredes"

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    Ítem
    Chemical Profiling, Antioxidant, Anticholinesterase, and Antiprotozoal Potentials of Artemisia copa Phil. (Asteraceae)
    (2020) Maria José Larrazábal-Fuentes; Carlos Fernández-Galleguillos; Jenifer Palma-Ramírez; Javier Romero-Parra; Kevin Sepúlveda; Jorge González; Adrián Paredes; Jorge Bórquez; Mario J. Simirgiotis; Javier Echeverría; Alexandra Galetović
    Artemisia copa Phil. (Asteraceae) (known as copa-copa) is a native species of Chile used as an infusion in traditional medicine by Atacameños people in the Altiplano, highlands of northern Chile. In this research, we have investigated for the first time the cholinesterase inhibition potential against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and the chemical profiling of the infusions prepared from the aerial parts of A. copa by high resolution spectrometry. In addition, total phenolic, total flavonoid content, antioxidant (DPPH, FRAP, and ORAC) and antiprozoal activity were tested. Artemisia copa showed good inhibitory activity against AChE and BChE (3.92 ± 0.08 µg/ml and 44.13 ± 0.10 µg/ml). The infusion displayed a total phenolics content of 155.6 ± 2.9 mg of gallic acid equivalents/g and total flavonoid content of 5.5 ± 0.2 mg quercetin equivalents/g. Additionally, trypanocidal activity against Trypanosoma cruzi was found (LD50 of 131.8 µg/ml). Forty-seven metabolites were detected in the infusion of A. copa including several phenolic acids and flavonoids which were rapidly identified using ultrahigh performance liquid chromatography orbitrap mass spectrometry analysis (UHPLC-Orbitrap-MS) for chemical profiling. The major compounds identified in the infusions were studied by molecular docking against AChE and BChE. The UHPLC-MS fingerprints generated can be also used for the authentication of these endemic species. These findings reveal that A. copa infusions can be used as beverages with protective effects.
  • Miniatura
    Ítem
    Determining the Potential of Haematococcus pluvialis Oleoresin as a Rich Source of Antioxidants
    (2019) Mari Carmen Ruiz Domínguez; Carolina Espinosa; Adrián Paredes; Jenifer Palma; Carolina Jaime; Carlos Vílchez; Pedro Cerezal
    Haematococcus pluvialis is known to be a natural source of antioxidants for numerous applications. In this study, an oleoresin rich in carotenoids extracted by supercritical CO2 treatment of H. pluvialis was extensively characterized for its antioxidant capacity. Carotenoid content, fatty acid profile, total phenol content, antioxidant capacity, and viscosity of the oleoresin were determined with the aim of ascertaining the potential of the oleoresin in terms of its antioxidant content for food applications. The oleoresin contained 96.22 mg/g of total astaxanthin (which includes free astaxanthin and astaxanthin esters) and mostly included unsaturated fatty acids (~78% of total fatty acids). High total phenol content and ferric reducing antioxidant potential indicated high antioxidant capacity, but oxygen radical absorbance capacity was lower compared to the oleoresin samples obtained from other species. The oleoresin was a non-Newtonian fluid since it had shear-thinning (pseudoplastic) and shear-thickening (dilatant) flow. Therefore, the H. pluvialis oleoresin is a potential alternative in developing functional ingredients for designing healthy food products. To the best of our knowledge, this is the first study that has reported an extensive characterization of the antioxidant properties of a microalgal oleoresin obtained by means of supercritical CO2 fluid extraction.
  • Miniatura
    Ítem
    Effect of Lampaya medicinalis Phil. (Verbenaceae) and Palmitic Acid on Insulin Signaling and Inflammatory Marker Expression in Human Adipocytes
    (2024) Gabriela Yuri; Mariana Cifuentes; Pedro Cisternas; Adrián Paredes; Paulina Ormazabal
    Background: Aging and obesity are associated with insulin resistance (IR) and low-gradeinflammation. Molecularly, IR is characterized by a reduction in glucose uptake and insulin signaling(IRS-1/Akt/AS160 pathway), while inflammation may result from upregulated NF-κB pathwayafter low Tyr-IκBαphosphorylation. Upregulated phosphatase activity of PTP1B is associated withimpaired insulin signaling and increased inflammation. Plasma levels of palmitic acid (PA) areelevated in obesity, triggering inflammation and disruption of insulin signaling. Traditional medicinein Northern Chile uses oral infusions ofLampaya medicinalisPhil. (Verbenaceae) to treat inflammatoryconditions. Significant amounts of flavonoids are found in the hydroethanolic extract of Lampaya(HEL), which may account for its biological activity. The aim of this work was to study the effect ofHEL and PA on insulin signaling and glucose uptake as well as inflammatory marker expression inhuman adipocytes. Methods: We studied HEL effects on PA-induced impairment on insulin signaling,glucose uptake and inflammatory marker content in human SW872 adipocytes. HEL cytotoxicity wasassessed in adipocytes at different concentrations (0.01 to 10 g/mL). Adipocytes were incubated or notwith PA (0.4 mM, 24 h) with or without HEL (2 h pre-incubation), and then stimulated with insulin(10 min, 100 mM) or a vehicle. Phospho-IRS-1, phospho-Akt, phospho-AS160, phospho-NF-κB andphospho-IκBα, as well as protein levels of PTP1B, were assessed using Western blotting, and glucoseuptake was evaluated using the 2-NBDG analogue. Results: At the assessed HEL concentrations, nocytotoxic effects were observed. PA decreased insulin-stimulated phospho-Akt and glucose uptake,while co-treatment with HEL increased such markers. PA decreased phospho-IRS-1 and phospho-Tyr-IκBα. On the other hand, incubation with HEL+PA decreased phospho-AS160 and phospho-NF-κBcompared with cells treated with PA alone. Conclusion: Our results suggest a beneficial effect ofHEL by improving PA-induced impairment on molecular markers of insulin signaling, glucoseuptake and inflammation in adipocytes. Further studies are necessary to elucidate whether lampayamay constitute a preventive strategy for people whose circulating PA levels contribute to IR andinflammation during aging and obesity.