Browsing by Author "Bridi, Raquel"

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    A chemically-induced acute model of maple syrup urine disease in rats for neurochemical studies
    (2006) Bridi, Raquel; Fontella, Fernanda U.; Pulrolnik, Vania; Braun, Cesar A.; Zorzi, Giovanni K.; Coelho, Daniella; Wajner, Moacir; Vargas, Carmen Regla; Dutra-Filho, Carlos Severo
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    A Polyvinylpolypyrrolidone (PVPP)-Assisted Folin-Ciocalteu Assay to Assess Total Phenol Content of Commercial Beverages
    (2014) Bridi, Raquel; Troncoso, M.; Folch Cano, C.; Fuentes, J.; Speisky, Hernán; López Alarcón, Camilo Ignacio
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    Antiinflammatory and antinociceptive activities of extracts and isolated compounds from Stachytarpheta cayennensis
    (1998) Schapoval, E.E.; Vargas, M.R.; Chaves, C.G.; Bridi, Raquel; Zuanazzi, J.A.; Henriques, A.T.
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    ANTIOXIDANT ACTIVITY IN SOUTHERN BRAZIL HYPERICUM SPECIES
    (2008) Bernardi, A.P.M.; López Alarcón, Camilo Ignacio; Aspee, A.; Rech, S.B.; Von Poser, G.L.; Bridi, Raquel; Dutrafilho C.S.; Lissi, E.
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    Antioxidant activity of flavonoids isolated from Hypericum ternum
    (2007) Bernardi, A.P.M.; López Alarcón, Camilo Ignacio; Aspee, A.; Rech, S.; Von Poser, G.L.; Bridi, Raquel; Lissi, E.
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    Antioxidant Effect of Extracts from Native Chilean Plants on the Lipoperoxidation and Protein Oxidation of Bovine Muscle
    (2019) Bridi, Raquel; Giordano, Ady; Penailillo, Maria Fernanda; Montenegro, Gloria
    The present study investigated the antioxidant potential and the ability to inhibit lipid and protein oxidation in bovine meat of four native Chilean species: canelo (Drimys winteri), nalca (Gunnera tinctoria), tiaca (Caldcluvia paniculata), and ulmo (Eucryphia cordifolia). Phenolic acids (gallic, chlorogenic, caffeic, and coumaric) and flavonoids (catechin, epicatechin, and rutin) were identified and quantified by HPLC-MS/MS. Drimys winteri extract exhibited the highest antioxidant capacity evaluated by oxygen radical absorption capacity-red pyrogallol method (ORAC-PGR) and ferric ion reducing antioxidant power (FRAP) assays. All extracts decreased lipid oxidation induced by 2,2'-azo-bis(2-amidinopropane) dihydrochloride (AAPH) derived peroxyl radicals by anywhere between 30% and 50% the. In addition, canelo and nalca extracts decreased spontaneous oxidation by around 57% and 37% in relation to the control group, being even more efficient than butylated hydroxyanisole (BHT) a synthetic antioxidant. Protein oxidation in the myofibrillar proteins was evaluated by the formation of protein carbonyls and loss of protein thiols. The canelo, ulmo, and nalca extracts decreased the formation of carbonyls by around 30%. Plant extracts and BHT did not show an antioxidant effect on protein thiol loss. However, tiaca and ulmo extracts exerted a pro-oxidant effect, favoring the oxidation of sulfhydryl groups. The oxidizing system induced structural changes in myofibrillar protein (SDS-PAGE). A protective effect on protein structure from the canelo extract can be observed during the incubation when compared to samples incubated with AAPH.
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    Benzophenones from Hypericum carinatum
    (2005) Bernardi, A.P.M.; Ferraz, A.B.F.; Albring, D.V.; Bordignon, S.A.L.; Schripsema, J.; Bridi, Raquel; Dutra-Filho, C.S.; Henriques, A.T.; Von Poser, G.L.
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    Bioactive polyphenols and antioxidant capacity of Azara petiolaris and Azara integrifolia Honeys
    (2018) Giordano Villatoro, Ady; Retamal, Mauricio; Leyton, Felipe; Martinez, Patricia; Bridi, Raquel; Velasquez, Patricia; Montenegro Rizzardini, Gloria
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    Comparative Study of Phenolic Content and Antioxidant and Hepatoprotective Activities of Unifloral Quillay Tree (Quillaja saponaria Molina) and Multifloral Honeys from Chile
    (2024) Núñez Pizarro, Paula; Montenegro Rizzardini, Gloria; Núñez Quijada, Gabriel Israel; Andía Kohnenkampf, Marcelo Edgardo; Espinosa Bustos, Christian Marcelo; de Camargo, Adriano Costa; Oyarzún Isamitt, Juan Esteban; Bridi, Raquel
    Honey is a natural sweet element that bees make with flower nectar, revered for its distinct flavor, nutritional value, and potential health benefits. Chilean beekeeping has a diverse range of honey varieties, many of which are unique. The quillay (Quillaja saponaria Molina, soapbark tree) is a Chilean endemic tree whose honey has not been studied in depth. We characterized various Chilean honeys with different botanical origins, with a particular focus on quillay tree honey, analyzing its total phenolic and flavonoid content and its antioxidant activities. Cytotoxicity and hepatoprotective activity were also evaluated using HuH-7 cells. The Spearman correlation between the percentage of quillay pollen in the honey samples and the total phenolic content (R = 0.72; p < 0.05), plus the oxygen radical absorbance capacity, suggests that compounds from quillay contribute to the overall antioxidant capacity of honey. Unifloral quillay honey extracts also protect hepatic cells from oxidative damage induced by peroxyl radicals generated by AAPH. This analysis sheds light on the potential of quillay tree honey, underscoring its significance as a natural source of bioactive phenolic compounds with possible hepatoprotective effects.
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    Differences between phenolic content and antioxidant capacity of quillay Chilean honeys and their separated phenolic extracts
    (2017) Bridi, Raquel; Nuñez-Quijada, Gabriel; Aguilar, Patricia; Martínez, Patricia; Lissi, Eduardo; Giordano Villatoro, Ady; Montenegro Rizzardini, Gloria
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    Distribution and reactivity of gallates toward galvinoxyl radicals in SDS micellar solutions - Effect of the alkyl chain length
    (2011) Bridi, Raquel; Aliaga, Carolina; Aspee, Alexis; Abuin, Elsa; Lissi, Eduardo
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    Essential oils from five southern brazilian species of myrcia(myrtaceae)
    (1997) Henriques, Amelia.T.; Sobral, Marcos; Bridi, Raquel; Vérin, Pierre; Menut, Chantal; Lamaty, Gerard; Bessiére, Jean Marie
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    Evaluation of new natural compound formulations on the modification of metabolic syndrome components among overweight adults
    (2022) Ebensperger, Roberto; Moreno, Manuel; Plaza, Cristian; Bridi, Raquel
    Overweight and obesity, increasingly frequent conditions in Chile and the world, are defined as chronic diseases characterized by the excessive accumulation of body fat, that can be detrimental to health. Excess body fat is the main pathogenic factor for the development of insulin resistance and metabolic syndrome, the latter characterized by a cluster of metabolic abnor-malities that increase risk of metabolic diseases and cardiovascular mortality. The objective of this preliminary cross-sectional, observational study was to evaluate a new formulation of natural compounds, Delphinol (R), resveratrol and oleanolic acid, against metabolic syndrome components in a young population with excess weight, through the intake during 22 weeks of the new formulation. The evaluation was carried out based on the clinical and anthropometric status of 20 volunteer subjects (both gender, 18 to 30 years and BMI26 to 42), medical evaluation and laboratory tests using each metabolic syndrome component (abdominal obesity, triglycerides, HDL, blood pressure y fasting glicaemia). It was observed that with the daily intake of this formulation there was a significant reduction in blood glucose levels, HOMA-IR index, triglycerides and an increase in HDL-cholesterol. These preliminary results would translate into a benefit in the health status of overweight and obese individuals, which would impact on reducing rates of metabolic syndrome. Thus, slowing down the progression of chronic diseases such as diabetes and dyslipidemia, and also contributing to decreasing the associated cardiometabolic risk.
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    Evaluation of the mechanisms involved in leucine-induced oxidative damage in cerebral cortex of young rats
    (2005) Bridi, Raquel; Latini, A.; Braum, C.A.; Zorzi, G.K.; Wajner, M.; Lissi, E.; Dutra, C.S.
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    Experimental hyperphenylalaninemia provokes oxidative stress in rat brain
    (2002) Kienzle Hagen, M.E.; Pederzolli, C.D.; Sgaravatti, A.M.; Bridi, Raquel; Wajner, M.; Wannmacher, C.M.D.; Wyse, A.T.S.; Dutra, C.S.
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    Exudate and Propolis from Escallonia pulverulenta: Phytochemical Characterization and Antibacterial Activity
    (2024) Jorquera, Bairon; Valenzuela-Barra, Gabriela; Mayorga, Ailin; Mejia, Jessica; Nunez, Gabriel; Gomez, Miguel; Montenegro, Gloria; Quezada, Waleska E. Vera; Echeverria, Javier; de Camargo, Adriano Costa; von Poser, Gilsane Lino; Bridi, Raquel
    Propolis is a complex mixture formed from exudates that bees collect from plants and then mix with beeswax and their own salivary enzymes. Chilean propolis is characterized by the presence of phenolic compounds, which are considered responsible for the biological activities. The endemic species Escallonia pulverulenta (Ruiz and Pav.) Pers. [Escalloniaceae] is a recognized source of exudate to produce propolis. This study reports for the first time the chemical profile and antibacterial activity of E. pulverulenta exudate and leaves, as well as two samples of Chilean propolis. Palynological and morphological analysis showed the presence of E. pulverulenta as one of the main species in the propolis samples. UPLC-MS/MS analyses enabled the identification of phenolic acids in the leaves and in the propolis. Conversely, flavonoids are mainly present in exudates and propolis. Quercetin is the most abundant flavonol in the exudate, with similar concentrations in the propolis samples. Nevertheless, the main compound present in both samples of propolis was the flavanone pinocembrin. The antibacterial results obtained for exudate and propolis have shown a similar behavior, especially in the inhibition of Streptococcus pyogenes. These results show the importance of the exudates collected by the bees in the chemical composition and antibacterial capacity of propolis.
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    Hepatoprotective species from the Chilean medicinal flora : Junellia spathulata (Verbenaceae)
    (2021) Bridi, Raquel; Lino von Poser, G.; Gómez, Miguel; Andía Kohnenkampf, Marcelo Edgardo; Oyarzún Isamitt, Juan Esteban; Núñez, P.; Vasquez Arias, A. J.; Espinosa Bustos, Christian Marcelo
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    Hepatoprotective species from the Chilean medicinal flora: Junellia spathulata (Verbenaceae)
    (2021) Bridi, Raquel; von Poser, Gilsane Lino; Gomez, Miguel; Andia, Marcelo E.; Esteban Oyarzun, Juan; Nunenz, Paula; Vasquez Arias, Ariadsna Jael; Espinosa-Bustos, Christian
    Ethnopharmacological relevance: Chilean population relies on medicinal plants for treating a wide range of illnesses, especially those of the gastrointestinal system. Junellia spathulata (Gillies & Hook.) Moldenke var. spathulata (Verbenaceae), called as "verbena-azul-de-cordilleira", is a medicinal plant native to Argentina and Chile traditionally used for treating digestive disorders. Although the species of the genus ar e important as therapeutic resources for the Andean population, the plants are ver y scarcely studied.