raquel bridi - Academia.edu (original) (raw)
Papers by raquel bridi
Current opinion in food science, Jun 1, 2024
Food Bioscience, Jan 31, 2024
Revista Medica De Chile, Feb 28, 2023
Food Research International
Revista chilena de nutrición
Evaluación de una nueva formulación de compuestos naturales sobre la modificación de los componen... more Evaluación de una nueva formulación de compuestos naturales sobre la modificación de los componentes del síndrome metabólico en adultos con sobrepeso Evaluation of new natural compound formulations on the modification of metabolic syndrome components among overweight adults
In this work, we have evaluated the reactivity of methyl gallate, propyl gallate, and n-octyl gal... more In this work, we have evaluated the reactivity of methyl gallate, propyl gallate, and n-octyl gallate toward galvi- noxyl radicals in homogeneous solution (ethanol) and sodium dodecyl sulfate micelles. In ethanol, the rate of galvinoxyl consumption was independent of the gallate's alkyl chain length. On the other hand, reaction rates in micelles were de- pendent on the length of the gallate alkyl chain. Measurements of the rate of the reaction at different pH show that, even at pH 7.0, the reaction mainly involves the monodeprotonated anionic form of the gallates. Plots of reaction rates as a function of the surfactant concentration allowed us to evaluate the distribution of the gallates (KGH) and an apparent rate constant defined by the product between the intramicellar rate constant of the anion (kG � ) and its partition constant (KG � ). The values of the increment of the apparent rate constant per methylene group in the alkyl chain strongly suggest that in- tramicellar rate ...
biloba (Ginkgoaceae) é uma espécie de uso milenar, originária da Ásia, sendo atualmente a droga m... more biloba (Ginkgoaceae) é uma espécie de uso milenar, originária da Ásia, sendo atualmente a droga mais comercializada na Europa, com 1,2 milhão de prescrições por mês. Ensaios clínicos e farmacológicos das preparações obtidas a partir desse vegetal demonstraram sua eficácia na insuficiência vascular cerebral, artrite, reumatismo e patologias associadas a geração de radicais livres. As formas farmacêuticas são preparadas a partir de um extrato padronizado (EGb 761) ou extratos brutos. O extrato padronizado EGb 761 contém 24% de flavonóides e 6% de terpenos. Substâncias como biflavonóides e ácidos ginkgólicos, presentes na planta in natura, são removidos. No Brasil, além dos extratos citados, as folhas secas e moídas são comercializadas em cápsulas, isoladamente ou em associações. Visando avaliar a qualidade das matérias-primas e fitoterápicos comercializados em Porto Alegre, várias preparações de Ginkgo biloba estão sendo analisadas através de métodos qualitativos e quantitativos. De dez amostras analisadas por CCD, somente 40 % apresentaram perfil cromatográfico semelhante aqueles obtidos com extratos metanólicos preparados a partir dos comprimidos revestidos TanakanÒ e TeboninÒ (Egb 761). Algumas preparações não apresentaram rutina, o principal flavonóide presente na planta. Além disso, algumas amostras não continham flavonóides, apresentando resultado positivo no teste para amido. Através de exame microscópico, alguns extratos mostraram fragmentos de folhas. As amostras também estão sendo avaliadas através de métodos espectrofotométricos (UV). Com os resultados obtidos até então, verifica-se que há negligência na elaboração desses fitoterápicos. Dessa forma, o controle de qualidade é fundamental para que os produtos manufaturados a partir do Ginkgo, além do EGb 761, apresentem maior qualidade a fim de garantir a eficácia e segurança.
Food Analytical Methods, 2014
The use of a Folin?Ciocalteu (FC) assay to assess total phenolics in certain foods may be limited... more The use of a Folin?Ciocalteu (FC) assay to assess total phenolics in certain foods may be limited by the inability of this assay to discriminate between phenolics and non-phenolic reducing compounds. In the present study, we have mentioned the usefulness of an insoluble water-synthetic polymer, polyvinylpolypyrrolidone (PVPP), to separate phenolics and non-phenolic reducing compounds (i.e., sugars, ascorbic acid, and sulfite) from their original food matrix. After employing three consecutive cycles adding PVPP, all polyphenols tested (including phenolic and cinnamic acids) showed an adsorption percentage (AP) to PVPP higher than 90 %. When tested in various beverages, the PVPP-based pretreatment affected in different ways the FC index, depending on the food matrix. A low AP was evidenced in the case of orange juice, most probably related to the high content of ascorbic acid in such samples. In contrast, a high adsorption to PVPP was obs
Antioxidants
Peanut skin is a rich source of bioactive compounds which may be able to reduce the risk factors ... more Peanut skin is a rich source of bioactive compounds which may be able to reduce the risk factors associated with metabolic syndromes. This study aimed to characterize bio-compounds from peanut skin (Arachis hypogaea) and their bioactivity (antioxidant activity, inhibition of lipase, and carbohydrase enzymes) and to evaluate their anti-proliferative properties in colorectal cancer cells (HCT116) upon in vitro digestion. Peanut skin was digested in two sequential phases, and the final content, named phase-1 (P1) and phase-2 (P2) extracts, was evaluated. Several bioactive compounds were positively identified and quantified by liquid chromatography, including quinic acid, released especially after in vitro digestion. The total phenolic content and, regardless of the method, the antioxidant activity of P1 was higher than P2. P1 also showed a lower enzyme inhibitory concentration IC50 than P2, lipase, and α-glucosidase. For cell viability in HCT116 cells, lower concentrations of P1 were f...
Neste trabalho foi realizado um estudo exploratório sobre o padrão de prescrição de medicamentos ... more Neste trabalho foi realizado um estudo exploratório sobre o padrão de prescrição de medicamentos a base de Hypericum perforatum por médicos psiquiatras na cidade de Porto Alegre - RS. O desenho foi um estudo transversal, exploratório, por meio de entrevista semi-estruturada. Dos 37 psiquiatras entrevistados apenas 2 prescrevem estes medicamentos, para o tratamento de depressão leve e moderada, quando seus pacientes apresentam intolerância aos antidepressivos sintéticos. Eles consideram os resultados terapêuticos de regulares a bons e os efeitos adversos, de leves a inexistentes. A maioria dos médicos relata que tem conhecimento da utilização de H. perforatum em casos de depressão leve a moderada, principalmente através de artigos científicos e livros. A suposição de que estes produtos são pouco eficazes é a principal justificativa para sua não prescrição. Os resultados indicam que os psiquiatras conhecem medicamentos à base de H. perforatum, mas que a prescrição dos mesmos não é usu...
Mini-Reviews in Medicinal Chemistry
Background: Liver disease rates are gradually increasing over the years, becoming a severe public... more Background: Liver disease rates are gradually increasing over the years, becoming a severe public health problem. The indiscriminate use of drugs associated with a rich fat diet, high consumption of alcoholic beverages, and exposure to viral infections and lipid peroxidative products are considered the chief factors for developing hepatic disorders. Owing to the absence of reliable hepatoprotective drugs in the therapeutic arsenal, since they present a high incidence of adverse reactions and/or lack of efficacy in some cases, liver diseases are widely treated with medicinal plants. Among them are the plants producing iridoids, which are believed to be good remedies for liver disease due to their bitter taste. The hepatoprotective effect of iridoids and extracts, rich in these compounds, has been demonstrated, both in vitro and in vivo. Objective: This review aims to scrutinize the available literature related to the hepatoprotective activity of iridoids. Methods: The information was...
Antioxidants
Chickpeas are rich sources of bioactive compounds such as phenolic acids, flavonoids, and isoflav... more Chickpeas are rich sources of bioactive compounds such as phenolic acids, flavonoids, and isoflavonoids. However, the contribution of insoluble-bound phenolics to their antioxidant properties remains unclear. Four varieties of chickpeas were evaluated for the presence of soluble (free and esterified) and insoluble-bound phenolics as well as their antiradical activity, reducing power and inhibition of peroxyl-induced cytotoxicity in human HuH-7 cells. In general, the insoluble-bound fraction showed a higher total phenolic content. Phenolic acids, flavonoids, and isoflavonoids were identified and quantified by UPLC-MS/MS. Taxifolin was identified for the first time in chickpeas. However, m-hydroxybenzoic acid, taxifolin, and biochanin A were the main phenolics found. Biochanin A was mostly found in the free fraction, while m-hydroxybenzoic acid was present mainly in the insoluble-bound form. The insoluble-bound fraction made a significant contribution to the reducing power and antirad...
In the present work we studied the reaction under gastric conditions of pyrogallol red (PGR), a p... more In the present work we studied the reaction under gastric conditions of pyrogallol red (PGR), a polyphenolic dye, with nitrous acid (HONO). PGR has been used as a model polyphenol due to its strong UV-visible absorption and its high reactivity towards reactive species (radicals and non-radicals, RS). The reaction was followed by UV-visible spectroscopy and high performance liquid chromatography (HPLC). A clear decrease of the PGR absorbance at 465 nm was observed, evidencing an efficient bleaching of PGR by HONO. In the initial stages of the reaction, each HONO molecule nearly consumed 2.6 PGR molecules while, at long reaction times, ca. 7.0 dye molecules were consumed per each reacted HONO. This result is interpreted in terms of HONO recycling. During the PGR-HONO reaction, nitric oxide was generated in the micromolar range. In addition, the rate of PGR consumption induced by HONO was almost totally abated by argon bubbling,
Molecules, 2020
Nonalcoholic fatty liver disease (NAFLD) is a major cause of morbidity and mortality worldwide. A... more Nonalcoholic fatty liver disease (NAFLD) is a major cause of morbidity and mortality worldwide. Additional therapies using functional foods and dietary supplements have been investigated and used in clinical practice, showing them to be beneficial. Honeybee pollen from Chile has shown a large concentration of phenolic compounds and high antioxidant activity. In this work, we characterized twenty-eight bee pollen extracts from the central zone of Chile according to botanical origin, phenolic profile, quercetin concentration, and antioxidant activity (FRAP and ORAC-FL). Our results show a statistically significant positive correlation between total phenolic content and antioxidant capacity. Selected samples were evaluated on the ability to reverse the steatosis in an in vitro cell model using Hepa1-6 cells. The pollen extracts protected Hepa1-6 cells against oxidative damage triggered by 2,2′-azo-bis(2-amidinopropane) dihydrochloride (AAPH)derived free radicals. This effect can be cre...
Ciencia e investigación agraria, 2017
2017. Differences between phenol content and antioxidant capacity of quillay Chilean honeys and t... more 2017. Differences between phenol content and antioxidant capacity of quillay Chilean honeys and their phenolic extracts. Cien. Inv. Agr. 44(3): 252-261. The differences between entire quillay honeys and their separated phenolic extracts in terms of phenolic content, flavonoid content and scavenging activity assessed through an Oxygen Radicals Absorbance Capacity (ORAC) assay were determined. The separated phenolic extracts of honey were obtained using Amberlite XAD-2, which is the procedure most used in analytical methods, biological assays and functional food development. The results showed that phenolic and flavonoid contents and antioxidant activity were higher in entire honeys than in their separated phenolic extracts. The recovery of phenolic acids and flavonoids was variable and depended upon the method employed. The application of polyvinylpolypyrrolidone (PVPP), a water insoluble synthetic polymer, in the separated extracts indicated an important influence of non-phenolic reducing compounds in the polyphenolic content measured by the Folin-Ciocalteu method. This showed the elution with methanol of these compounds together with phenolic compounds using an Amberlite XAD-2 column. The antioxidant capacity assessed through ORAC-FL and ORAC-PGR was less influenced by the interference of non-phenolic compounds than by that of total phenolic and flavonoid contents.
Current opinion in food science, Jun 1, 2024
Food Bioscience, Jan 31, 2024
Revista Medica De Chile, Feb 28, 2023
Food Research International
Revista chilena de nutrición
Evaluación de una nueva formulación de compuestos naturales sobre la modificación de los componen... more Evaluación de una nueva formulación de compuestos naturales sobre la modificación de los componentes del síndrome metabólico en adultos con sobrepeso Evaluation of new natural compound formulations on the modification of metabolic syndrome components among overweight adults
In this work, we have evaluated the reactivity of methyl gallate, propyl gallate, and n-octyl gal... more In this work, we have evaluated the reactivity of methyl gallate, propyl gallate, and n-octyl gallate toward galvi- noxyl radicals in homogeneous solution (ethanol) and sodium dodecyl sulfate micelles. In ethanol, the rate of galvinoxyl consumption was independent of the gallate's alkyl chain length. On the other hand, reaction rates in micelles were de- pendent on the length of the gallate alkyl chain. Measurements of the rate of the reaction at different pH show that, even at pH 7.0, the reaction mainly involves the monodeprotonated anionic form of the gallates. Plots of reaction rates as a function of the surfactant concentration allowed us to evaluate the distribution of the gallates (KGH) and an apparent rate constant defined by the product between the intramicellar rate constant of the anion (kG � ) and its partition constant (KG � ). The values of the increment of the apparent rate constant per methylene group in the alkyl chain strongly suggest that in- tramicellar rate ...
biloba (Ginkgoaceae) é uma espécie de uso milenar, originária da Ásia, sendo atualmente a droga m... more biloba (Ginkgoaceae) é uma espécie de uso milenar, originária da Ásia, sendo atualmente a droga mais comercializada na Europa, com 1,2 milhão de prescrições por mês. Ensaios clínicos e farmacológicos das preparações obtidas a partir desse vegetal demonstraram sua eficácia na insuficiência vascular cerebral, artrite, reumatismo e patologias associadas a geração de radicais livres. As formas farmacêuticas são preparadas a partir de um extrato padronizado (EGb 761) ou extratos brutos. O extrato padronizado EGb 761 contém 24% de flavonóides e 6% de terpenos. Substâncias como biflavonóides e ácidos ginkgólicos, presentes na planta in natura, são removidos. No Brasil, além dos extratos citados, as folhas secas e moídas são comercializadas em cápsulas, isoladamente ou em associações. Visando avaliar a qualidade das matérias-primas e fitoterápicos comercializados em Porto Alegre, várias preparações de Ginkgo biloba estão sendo analisadas através de métodos qualitativos e quantitativos. De dez amostras analisadas por CCD, somente 40 % apresentaram perfil cromatográfico semelhante aqueles obtidos com extratos metanólicos preparados a partir dos comprimidos revestidos TanakanÒ e TeboninÒ (Egb 761). Algumas preparações não apresentaram rutina, o principal flavonóide presente na planta. Além disso, algumas amostras não continham flavonóides, apresentando resultado positivo no teste para amido. Através de exame microscópico, alguns extratos mostraram fragmentos de folhas. As amostras também estão sendo avaliadas através de métodos espectrofotométricos (UV). Com os resultados obtidos até então, verifica-se que há negligência na elaboração desses fitoterápicos. Dessa forma, o controle de qualidade é fundamental para que os produtos manufaturados a partir do Ginkgo, além do EGb 761, apresentem maior qualidade a fim de garantir a eficácia e segurança.
Food Analytical Methods, 2014
The use of a Folin?Ciocalteu (FC) assay to assess total phenolics in certain foods may be limited... more The use of a Folin?Ciocalteu (FC) assay to assess total phenolics in certain foods may be limited by the inability of this assay to discriminate between phenolics and non-phenolic reducing compounds. In the present study, we have mentioned the usefulness of an insoluble water-synthetic polymer, polyvinylpolypyrrolidone (PVPP), to separate phenolics and non-phenolic reducing compounds (i.e., sugars, ascorbic acid, and sulfite) from their original food matrix. After employing three consecutive cycles adding PVPP, all polyphenols tested (including phenolic and cinnamic acids) showed an adsorption percentage (AP) to PVPP higher than 90 %. When tested in various beverages, the PVPP-based pretreatment affected in different ways the FC index, depending on the food matrix. A low AP was evidenced in the case of orange juice, most probably related to the high content of ascorbic acid in such samples. In contrast, a high adsorption to PVPP was obs
Antioxidants
Peanut skin is a rich source of bioactive compounds which may be able to reduce the risk factors ... more Peanut skin is a rich source of bioactive compounds which may be able to reduce the risk factors associated with metabolic syndromes. This study aimed to characterize bio-compounds from peanut skin (Arachis hypogaea) and their bioactivity (antioxidant activity, inhibition of lipase, and carbohydrase enzymes) and to evaluate their anti-proliferative properties in colorectal cancer cells (HCT116) upon in vitro digestion. Peanut skin was digested in two sequential phases, and the final content, named phase-1 (P1) and phase-2 (P2) extracts, was evaluated. Several bioactive compounds were positively identified and quantified by liquid chromatography, including quinic acid, released especially after in vitro digestion. The total phenolic content and, regardless of the method, the antioxidant activity of P1 was higher than P2. P1 also showed a lower enzyme inhibitory concentration IC50 than P2, lipase, and α-glucosidase. For cell viability in HCT116 cells, lower concentrations of P1 were f...
Neste trabalho foi realizado um estudo exploratório sobre o padrão de prescrição de medicamentos ... more Neste trabalho foi realizado um estudo exploratório sobre o padrão de prescrição de medicamentos a base de Hypericum perforatum por médicos psiquiatras na cidade de Porto Alegre - RS. O desenho foi um estudo transversal, exploratório, por meio de entrevista semi-estruturada. Dos 37 psiquiatras entrevistados apenas 2 prescrevem estes medicamentos, para o tratamento de depressão leve e moderada, quando seus pacientes apresentam intolerância aos antidepressivos sintéticos. Eles consideram os resultados terapêuticos de regulares a bons e os efeitos adversos, de leves a inexistentes. A maioria dos médicos relata que tem conhecimento da utilização de H. perforatum em casos de depressão leve a moderada, principalmente através de artigos científicos e livros. A suposição de que estes produtos são pouco eficazes é a principal justificativa para sua não prescrição. Os resultados indicam que os psiquiatras conhecem medicamentos à base de H. perforatum, mas que a prescrição dos mesmos não é usu...
Mini-Reviews in Medicinal Chemistry
Background: Liver disease rates are gradually increasing over the years, becoming a severe public... more Background: Liver disease rates are gradually increasing over the years, becoming a severe public health problem. The indiscriminate use of drugs associated with a rich fat diet, high consumption of alcoholic beverages, and exposure to viral infections and lipid peroxidative products are considered the chief factors for developing hepatic disorders. Owing to the absence of reliable hepatoprotective drugs in the therapeutic arsenal, since they present a high incidence of adverse reactions and/or lack of efficacy in some cases, liver diseases are widely treated with medicinal plants. Among them are the plants producing iridoids, which are believed to be good remedies for liver disease due to their bitter taste. The hepatoprotective effect of iridoids and extracts, rich in these compounds, has been demonstrated, both in vitro and in vivo. Objective: This review aims to scrutinize the available literature related to the hepatoprotective activity of iridoids. Methods: The information was...
Antioxidants
Chickpeas are rich sources of bioactive compounds such as phenolic acids, flavonoids, and isoflav... more Chickpeas are rich sources of bioactive compounds such as phenolic acids, flavonoids, and isoflavonoids. However, the contribution of insoluble-bound phenolics to their antioxidant properties remains unclear. Four varieties of chickpeas were evaluated for the presence of soluble (free and esterified) and insoluble-bound phenolics as well as their antiradical activity, reducing power and inhibition of peroxyl-induced cytotoxicity in human HuH-7 cells. In general, the insoluble-bound fraction showed a higher total phenolic content. Phenolic acids, flavonoids, and isoflavonoids were identified and quantified by UPLC-MS/MS. Taxifolin was identified for the first time in chickpeas. However, m-hydroxybenzoic acid, taxifolin, and biochanin A were the main phenolics found. Biochanin A was mostly found in the free fraction, while m-hydroxybenzoic acid was present mainly in the insoluble-bound form. The insoluble-bound fraction made a significant contribution to the reducing power and antirad...
In the present work we studied the reaction under gastric conditions of pyrogallol red (PGR), a p... more In the present work we studied the reaction under gastric conditions of pyrogallol red (PGR), a polyphenolic dye, with nitrous acid (HONO). PGR has been used as a model polyphenol due to its strong UV-visible absorption and its high reactivity towards reactive species (radicals and non-radicals, RS). The reaction was followed by UV-visible spectroscopy and high performance liquid chromatography (HPLC). A clear decrease of the PGR absorbance at 465 nm was observed, evidencing an efficient bleaching of PGR by HONO. In the initial stages of the reaction, each HONO molecule nearly consumed 2.6 PGR molecules while, at long reaction times, ca. 7.0 dye molecules were consumed per each reacted HONO. This result is interpreted in terms of HONO recycling. During the PGR-HONO reaction, nitric oxide was generated in the micromolar range. In addition, the rate of PGR consumption induced by HONO was almost totally abated by argon bubbling,
Molecules, 2020
Nonalcoholic fatty liver disease (NAFLD) is a major cause of morbidity and mortality worldwide. A... more Nonalcoholic fatty liver disease (NAFLD) is a major cause of morbidity and mortality worldwide. Additional therapies using functional foods and dietary supplements have been investigated and used in clinical practice, showing them to be beneficial. Honeybee pollen from Chile has shown a large concentration of phenolic compounds and high antioxidant activity. In this work, we characterized twenty-eight bee pollen extracts from the central zone of Chile according to botanical origin, phenolic profile, quercetin concentration, and antioxidant activity (FRAP and ORAC-FL). Our results show a statistically significant positive correlation between total phenolic content and antioxidant capacity. Selected samples were evaluated on the ability to reverse the steatosis in an in vitro cell model using Hepa1-6 cells. The pollen extracts protected Hepa1-6 cells against oxidative damage triggered by 2,2′-azo-bis(2-amidinopropane) dihydrochloride (AAPH)derived free radicals. This effect can be cre...
Ciencia e investigación agraria, 2017
2017. Differences between phenol content and antioxidant capacity of quillay Chilean honeys and t... more 2017. Differences between phenol content and antioxidant capacity of quillay Chilean honeys and their phenolic extracts. Cien. Inv. Agr. 44(3): 252-261. The differences between entire quillay honeys and their separated phenolic extracts in terms of phenolic content, flavonoid content and scavenging activity assessed through an Oxygen Radicals Absorbance Capacity (ORAC) assay were determined. The separated phenolic extracts of honey were obtained using Amberlite XAD-2, which is the procedure most used in analytical methods, biological assays and functional food development. The results showed that phenolic and flavonoid contents and antioxidant activity were higher in entire honeys than in their separated phenolic extracts. The recovery of phenolic acids and flavonoids was variable and depended upon the method employed. The application of polyvinylpolypyrrolidone (PVPP), a water insoluble synthetic polymer, in the separated extracts indicated an important influence of non-phenolic reducing compounds in the polyphenolic content measured by the Folin-Ciocalteu method. This showed the elution with methanol of these compounds together with phenolic compounds using an Amberlite XAD-2 column. The antioxidant capacity assessed through ORAC-FL and ORAC-PGR was less influenced by the interference of non-phenolic compounds than by that of total phenolic and flavonoid contents.