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6 results on '"Dina Guzmán-Oyarzo"'

1. Controlled Release of Caffeic Acid and Pinocembrin by Use of nPSi-βCD Composites Improves Their Antiangiogenic Activity

Author

Dina Guzmán-Oyarzo, Jacobo Hernández-Montelongo, Carlos Rosas, Pamela Leal, Helga Weber, Marysol Alvear, and Luis A. Salazar

Subjects
antiangiogenic activity, caffeic acid, pinocembrin, polyphenols, HUVECs, controlled release, Pharmacy and materia medica, RS1-441
Abstract

Although polyphenols have great pharmacological potential, the main disadvantage is that they have low bioavailability at the desired site. Thus, the use of biocompatible systems for drug delivery is a strategy that is currently gaining great interest. The objective of this study is to evaluate the effect of microencapsulation of caffeic acid and pinocembrin on the antioxidant and antiangiogenic activity of both polyphenols, by the use of nPSi-βCD composite microparticles. For this HUVEC, cells were exposed to H2O2 and to treatments with polyphenols in solution and loaded in the composite microparticle. The polyphenols were incorporated into a microparticle using nanoporous silicon, chitosan and a β-cyclodextrin polymer as the biomaterial. The evaluation of the antiangiogenic effect of the treatments with polyphenols in solution and microencapsulated was carried out through functional tests, and the changes in the expression of target genes associated with the antioxidant pathway and angiogenesis was performed through qPCR. The results obtained show that the caffeic acid and pinocembrin have an antioxidant and antiangiogenic activity, both in solution as microencapsulated. In the caffeic acid, a greater biological effect was observed when it was incorporated into the nPSi-βCD composite microparticle. Our results suggest that the nPSi-βCD composite microparticle could be used as an alternative oral drug administration system.

Published
2022
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2. Use of nPSi-βCD Composite Microparticles for the Controlled Release of Caffeic Acid and Pinocembrin, Two Main Polyphenolic Compounds Found in a Chilean Propolis

Author

Dina Guzmán-Oyarzo, Tanya Plaza, Gonzalo Recio-Sánchez, Dulcineia S. P. Abdalla, Luis A. Salazar, and Jacobo Hernández-Montelongo

Subjects
controlled release, nanoporous silicon, βCD polymer, caffeic acid, pinocembrin, polyphenols, HUVECs, Pharmacy and materia medica, RS1-441
Abstract

Propolis is widely recognized for its various therapeutic properties. These are attributed to its rich composition in polyphenols, which exhibit multiple biological properties (e.g., antioxidant, anti-inflammatory, anti-angiogenic). Despite its multiple benefits, oral administration of polyphenols results in low bioavailability at the action site. An alternative to face this problem is the use of biomaterials at nano-micro scale due to its high versatility as carriers and delivery systems of various drugs and biomolecules. The aim of this work is to determine if nPSi-βCD microparticles are a suitable material for the load and controlled release of caffeic acid (CA) and pinocembrin (Pin), two of the main components of a Chilean propolis with anti-atherogenic and anti-angiogenic activity. Polyphenols and nPSi-βCD microparticles cytocompatibility studies were carried out with human umbilical vein endothelial cells (HUVECs). Results from physicochemical characterization demonstrated nPSi-βCD microparticles successfully retained and controlled release CA and Pin. Furthermore, nPSi-βCD microparticles presented cytocompatibility with HUVECs culture at concentrations of 0.25 mg/mL. These results suggest that nPSi-βCD microparticles could safely be used as an alternate oral delivery system to improve controlled release and bioavailability of CA or Pin—and eventually other polyphenols—thus enhancing its therapeutic effect for the treatment of different diseases.

Published
2019
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3. Efecto Antiangiogénico del Ácido Cafeico y Pinocembrina en el Proceso de Angiogénesis Fisiológica de Fetos de Pollo

Author

Carlos Rosas-C, Luis A. Salazar, Pedro Leiva-A, María Paz Riquelme, Dina Guzmán-Oyarzo, and Patricia Olivares-O

Subjects
Polifenoles, Angiogénesis, Pinocembrina, Anatomy, Ácido Cafeico
Abstract

RESUMEN: La angiogénesis es el proceso por el cual se forman nuevos vasos sanguíneos a partir de otros ya existentes. Para que esto se lleve a cabo de forma correcta debe existir un balance entre los factores proangiogénicos y los factores antiangiogénicos dentro del microambiente tisular. Por otra parte, la existencia de productos químicos naturales como los polifenoles, que son capaces de adquirirse en la dieta, inducen a estos factores a intervenir en el proceso de angiogénesis. Se administraron los polifenoles en filtros de metilcelulosa sobre la membrana alantocoriónica de huevos White Leghorn, manteniendo el posterior desarrollo normal del feto. Se utilizaron 15 fetos de pollo fijados en formalina tamponada, a los cuales se extrajo el corazón. El procesamiento de las muestras de corazón se realizó a través de técnicas histológicas, histoquímicas e inmunohistoquímica. Finalmente se evaluó la presencia del VEGF y la capacidad de formar vasos sanguíneos bajo el tratamiento con los polifenoles. La inmunorreactividad fue cuantificada mediante Image J®. Los resultados indican que Ácido cafeico y Pinocembrina disminuyen la densidad microvascular y la expresión de VEGF en corazones de fetos de pollo tratados con estos polifenoles. Tanto el Ácido Cafeico como la Pinocembrina cumplen un rol inhibitorio en el proceso de angiogénesis fisiológica en corazón de pollo, pudiendo modular las vías de señalización mediadas por los VEGFR o modulando la disponibilidad de VEGF. Estos polifenoles podrían utilizarse para el estudio de otros tejidos asociados a angiogénesis patológica.

Published
2020

4. Farmacogenómica de los anticoagulantes orales: la importancia de establecer algoritmos de dosificación en población chilena

Author

Franco Reyes, Rodrigo Boguen, Mario Vega, Neftalí Guzmán, Marcela Andaur, Pablo Letelier, and Dina Guzmán-Oyarzo

Subjects
education.field_of_study, Candidate gene, Dose, Pharmacogenomic Variants, Population, Anticoagulants, General Medicine, Computational biology, Biology, Vitamin k, Coumarins, Pharmacogenomics, Dosing, education
Abstract

There is an important interindividual variability in dose requirement for coumarinic anticoagulants, which could be explained by genetic and non-genetic factors. Among hereditary factors, there are gene polymorphisms that code the therapeutic target and the main enzyme responsible for their metabolism. However, there are other candidate genes that could modulate dose requirements. The is a paucity of pharmacogenomic platforms to determine dose requirements of coumarinics in the Chilean population. Therefore, algorithms considering different variables to adjust individual dosages are required. Herein, we analyze the available evidence about factors that can modify the effects of vitamin K antagonists and that should be incorporated to dosing algorithms.

Published
2020

5. [Pharmacogenomics of vitamin K antagonists]

Author

Neftalí, Guzmán, Mario, Vega, Franco, Reyes, Dina, Guzmán-Oyarzo, Marcela, Andaur, Rodrigo, Boguen, and Pablo, Letelier

Subjects
Vitamin K, Dose-Response Relationship, Drug, Genotype, Pharmacogenetics, Vitamin K Epoxide Reductases, Anticoagulants, Humans, Warfarin, Chile, Cytochrome P-450 CYP2C9
Abstract

There is an important interindividual variability in dose requirement for coumarinic anticoagulants, which could be explained by genetic and non-genetic factors. Among hereditary factors, there are gene polymorphisms that code the therapeutic target and the main enzyme responsible for their metabolism. However, there are other candidate genes that could modulate dose requirements. The is a paucity of pharmacogenomic platforms to determine dose requirements of coumarinics in the Chilean population. Therefore, algorithms considering different variables to adjust individual dosages are required. Herein, we analyze the available evidence about factors that can modify the effects of vitamin K antagonists and that should be incorporated to dosing algorithms.

Published
2019

6. Use of nPSi-βCD composite microparticles for the controlled release of caffeic acid and pinocembrin, two main polyphenolic compounds found in a chilean propolis

Author

Dulcinéia Saes Parra Abdalla, Tanya Plaza, Luis A. Salazar, Dina Guzmán-Oyarzo, Jacobo Hernandez-Montelongo, and Gonzalo Recio-Sánchez

Subjects
POLIFENÓIS, Antioxidant, medicine.medical_treatment, Pharmaceutical Science, lcsh:RS1-441, 02 engineering and technology, Article, lcsh:Pharmacy and materia medica, 03 medical and health sciences, chemistry.chemical_compound, Oral administration, medicine, Caffeic acid, polyphenols, 030304 developmental biology, HUVECs, 0303 health sciences, Pinocembrin, Chromatography, nanoporous silicon, pinocembrin, Propolis, 021001 nanoscience & nanotechnology, Controlled release, Bioavailability, chemistry, Polyphenol, βCD polymer, 0210 nano-technology, controlled release, caffeic acid
Abstract

Propolis is widely recognized for its various therapeutic properties. These are attributed to its rich composition in polyphenols, which exhibit multiple biological properties (e.g., antioxidant, anti-inflammatory, anti-angiogenic). Despite its multiple benefits, oral administration of polyphenols results in low bioavailability at the action site. An alternative to face this problem is the use of biomaterials at nano-micro scale due to its high versatility as carriers and delivery systems of various drugs and biomolecules. The aim of this work is to determine if nPSi-&beta, CD microparticles are a suitable material for the load and controlled release of caffeic acid (CA) and pinocembrin (Pin), two of the main components of a Chilean propolis with anti-atherogenic and anti-angiogenic activity. Polyphenols and nPSi-&beta, CD microparticles cytocompatibility studies were carried out with human umbilical vein endothelial cells (HUVECs). Results from physicochemical characterization demonstrated nPSi-&beta, CD microparticles successfully retained and controlled release CA and Pin. Furthermore, nPSi-&beta, CD microparticles presented cytocompatibility with HUVECs culture at concentrations of 0.25 mg/mL. These results suggest that nPSi-&beta, CD microparticles could safely be used as an alternate oral delivery system to improve controlled release and bioavailability of CA or Pin&mdash, and eventually other polyphenols&mdash, thus enhancing its therapeutic effect for the treatment of different diseases.

Published
2019

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