167 research outputs found
Natural products for the treatment of Type 2 Diabetes Mellitus
Type 2 diabetes mellitus is a metabolic disease characterized by persistent hyperglycemia. High blood sugar can produce long-term complications such as cardiovascular and renal disorders, retinopathy, and poor blood flow. Its development can be prevented or delayed in people with impaired glucose tolerance by implementing lifestyle changes or the use of therapeutic agents. Some of these drugs have been obtained from plants or have a microbial origin, such as galegine isolated from Galega officinalis, which has a great similarity to the antidiabetic drug metformin. Picnogenol, acarbose, miglitol, and voglibose are other antidiabetic products of natural origin. This review compiles the principal articles on medicinal plants used for treating diabetes and its comorbidities, as well as mechanisms of natural products as antidiabetic agents. Inhibition of α-glucosidase and α-amylase, effects on glucose uptake and glucose transporters, modification of mechanisms mediated by the peroxisome proliferator-activated receptor, inhibition of protein tyrosine phosphatase 1B activity, modification of gene expression, and activities of hormones involved in glucose homeostasis such as adiponectin, resistin, and incretin, and reduction of oxidative stress are some of the mechanisms in which natural products are involved. We also review the most relevant clinical trials performed with medicinal plants and natural products such as aloe, banaba, bitter melon, caper, cinnamon, cocoa, coffee, fenugreek, garlic, guava, gymnema, nettle, sage, soybean, green and black tea, turmeric, walnut, and yerba mate. Compounds of high interest as potential antidiabetics are: fukugetin, palmatine, berberine, honokiol, amorfrutins, trigonelline, gymnemic acids, gurmarin, and phlorizin.Fil: Barrios, José Luis. Universidad de Valencia; EspañaFil: Francini, Flavio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Schinella, Guillermo Raúl. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; Argentin
Actividad antioxidante y efecto cardioprotector de Ilex brasiliensis: un estudio comparativo con Ilex paraguariensis (yerba mate)
La relevancia de la investigación de Ilex brasiliensis (Spreng.) Loes. (Aquifoliaceae) se justifica en la proximidad filogenética y biogeográfica con Ilex paraguariensis (yerba mate), en su uso popular como sustituto o adulterante de la yerba mate y en la escasa información respecto a sus propiedades biológicas. Esta tesis estudia el órgano foliar que es la materia prima de uso popular para preparar las infusiones y se propone establecer características farmacognósticas, evaluar la actividad antioxidante y los efectos en la fisiopatología del daño miocárdico inducido por isquemia y reperfusión.\nEn el análisis micrográfico se distinguen caracteres morfoanatómicos diferenciales con I. paraguariensis, en particular: los tipos de estomas, la estructura del haz vascular y la vaina de esclerénquima de la vena media foliar.\nEl estudio de I. brasiliensis utilizando HPLC-PDA-UV demuestra dos características fitoquímicas diferenciales respecto I. paraguariensis: la ausencia total de cafeína y la mayor riqueza en isoquercitrina. El análisis con HPLC-ESI-MS pone en evidencia que I. brasiliensis posee una mayor variedad de flavonoides derivados de quercetina y kaempferol. Los métodos colorimétricos determinan una mayor concentración de fenoles totales y ácido ascórbico.\nI. brasiliensis posee una elevada actividad antioxidante in vitro como atrapador de radicales libres estables (DPPH y ABTS) y de especies reactivas derivadas del oxígeno y del nitrógeno (superóxido y peroxinitrito). También, la capacidad para inhibir la peroxidación lipídica enzimática y no enzimática de microsomas hepáticos de rata y proteger a las LDL de la peroxidación lipídica inducida por cobre. En comparación a I. paraguariensis, el extracto acuoso de I. brasiliensis tiene una mayor actividad antioxidante como atrapador de ABTS•+ y peroxinitrito y como reductor de Fe+3. Estos hallazgos se atribuyen a su mayor contenido de ácido ascórbico.\nLos resultados alcanzados demuestran, por primera vez, que un extracto acuoso de hojas de I. brasiliensis disminuye las alteraciones post-isquémicas de la función miocárdica y el daño oxidativo producidos como consecuencia del proceso de isquemia y reperfusión. Asimismo, que el mecanismo cardioprotector es dependiente de la NOS. Efectos similares se observan después del tratamiento con I. paraguariensis. Se postula que las acciones cardioprotectoras de I. brasiliensis no son simplemente debidas a sus propiedades redox; sino más bien, a la capacidad de algunos de sus constituyentes para unirse a proteínas dianas.Magister en Plantas Medicinale
Actividad antioxidante y efecto cardioprotector de <i>Ilex brasiliensis</i>: un estudio comparativo con <i>Ilex paraguariensis</i> (yerba mate)
La relevancia de la investigación de Ilex brasiliensis (Spreng.) Loes. (Aquifoliaceae) se justifica en la proximidad filogenética y biogeográfica con Ilex paraguariensis (yerba mate), en su uso popular como sustituto o adulterante de la yerba mate y en la escasa información respecto a sus propiedades biológicas. Esta tesis estudia el órgano foliar que es la materia prima de uso popular para preparar las infusiones y se propone establecer características farmacognósticas, evaluar la actividad antioxidante y los efectos en la fisiopatología del daño miocárdico inducido por isquemia y reperfusión.
En el análisis micrográfico se distinguen caracteres morfoanatómicos diferenciales con I. paraguariensis, en particular: los tipos de estomas, la estructura del haz vascular y la vaina de esclerénquima de la vena media foliar.
El estudio de I. brasiliensis utilizando HPLC-PDA-UV demuestra dos características fitoquímicas diferenciales respecto I. paraguariensis: la ausencia total de cafeína y la mayor riqueza en isoquercitrina. El análisis con HPLC-ESI-MS pone en evidencia que I. brasiliensis posee una mayor variedad de flavonoides derivados de quercetina y kaempferol. Los métodos colorimétricos determinan una mayor concentración de fenoles totales y ácido ascórbico.
I. brasiliensis posee una elevada actividad antioxidante in vitro como atrapador de radicales libres estables (DPPH y ABTS) y de especies reactivas derivadas del oxígeno y del nitrógeno (superóxido y peroxinitrito). También, la capacidad para inhibir la peroxidación lipídica enzimática y no enzimática de microsomas hepáticos de rata y proteger a las LDL de la peroxidación lipídica inducida por cobre. En comparación a I. paraguariensis, el extracto acuoso de I. brasiliensis tiene una mayor actividad antioxidante como atrapador de ABTS•+ y peroxinitrito y como reductor de Fe+3. Estos hallazgos se atribuyen a su mayor contenido de ácido ascórbico.
Los resultados alcanzados demuestran, por primera vez, que un extracto acuoso de hojas de I. brasiliensis disminuye las alteraciones post-isquémicas de la función miocárdica y el daño oxidativo producidos como consecuencia del proceso de isquemia y reperfusión. Asimismo, que el mecanismo cardioprotector es dependiente de la NOS. Efectos similares se observan después del tratamiento con I. paraguariensis. Se postula que las acciones cardioprotectoras de I. brasiliensis no son simplemente debidas a sus propiedades redox; sino más bien, a la capacidad de algunos de sus constituyentes para unirse a proteínas dianas.Facultad de Ciencias Exacta
Capacidad antioxidante total y contenido de polifenoles de vinos argentinos
Existe evidencia sobre los beneficios del consumo de dietas ricas en frutas y vegetales y una moderada cantidad de vinos tintos en situaciones de salud asociadas a la producción de riesgo oxidativo. Estos efectos protectores se atribuyen a la presencia en los alimentos citados de compuestos con actividad antioxidante, particularmente los polifenoles. En los vinos, los principales compuestos fenólicos son los ácidos galico y cafeico, epicatequina, catequina, cianidina y malvidina-3-glucósidos, rutina, miricetina, quercetina y resveratrol. La Argentina posee regiones muy aptas para la producción vitivinícola siendo el vino obtenido de la Vitis vinifera var. Malbec, uno de los más representativos del país. En la zona del Rio de La Plata y particularmente en Berisso se cultiva la Vitis labrusca var. Isabela de la cual se obtienen el denominado vino de la costa (VC). Existe escasa evidencia sobre la capacidad antioxidante total (CAT) de los vinos Malbec argentinos producidos en diferentes regiones y prácticamente ninguna sobre el vino de la costa. Objetivos: Como parte de un proyecto general del estudio de la capacidad antioxidante de productos naturales, en este trabajo se evalúa la CAT y el contenido de fenoles totales de vinos Malbec de 4 regiones vitivinícolas argentinas y del VC de Berisso utilizando diferentes modelos experimentales
Natural Products for the Treatment of Type 2 Diabetes Mellitus
Type 2 diabetes mellitus is a metabolic disease characterized by persistent hyperglycemia. High blood sugar can produce long-term complications such as cardiovascular and renal disorders, retinopathy, and poor blood flow. Its development can be prevented or delayed in people with impaired glucose tolerance by implementing lifestyle changes or the use of therapeutic agents. Some of these drugs have been obtained from plants or have a microbial origin, such as galegine isolated from Galega officinalis, which has a great similarity to the antidiabetic drug metformin. Picnogenol, acarbose, miglitol, and voglibose are other antidiabetic products of natural origin. This review compiles the principal articles on medicinal plants used for treating diabetes and its comorbidities, as well as mechanisms of natural products as antidiabetic agents. Inhibition of α-glucosidase and α-amylase, effects on glucose uptake and glucose transporters, modification of mechanisms mediated by the peroxisome proliferator-activated receptor, inhibition of protein tyrosine phosphatase 1B activity, modification of gene expression, and activities of hormones involved in glucose homeostasis such as adiponectin, resistin, and incretin, and reduction of oxidative stress are some of the mechanisms in which natural products are involved. We also review the most relevant clinical trials performed with medicinal plants and natural products such as aloe, banaba, bitter melon, caper, cinnamon, cocoa, coffee, fenugreek, garlic, guava, gymnema, nettle, sage, soybean, green and black tea, turmeric, walnut, and yerba mate. Compounds of high interest as potential antidiabetics are: fukugetin, palmatine, berberine, honokiol, amorfrutins, trigonelline, gymnemic acids, gurmarin, and phlorizin.Facultad de Ciencias MédicasCentro de Endocrinología Experimental y Aplicad
Phenolics as GABA-A receptor ligands:an updated review
Natural products can act as potential GABA modulators, avoiding the undesirable effects of traditional pharmacology used for the inhibition of the central nervous system such as benzodiazepines (BZD). Phenolics, especially flavonoids and phlorotannins, have been considered as modulators of the BZD-site of GABAA receptors (GABAARs), with sedative, anxiolytic or anticonvulsant effects. However, the wide chemical structural variability of flavonoids shows their potential action at more than one additional binding site on GABAARs, which may act either negatively, positively, by neutralizing GABAARs, or directly as allosteric agonists. Therefore, the aim of the present review is to compile and discuss an update of the role of phenolics, namely as pharmacological targets involving dysfunctions of the GABA system, analyzing both their different compounds and their mechanism as GABAergic modulators. We focus this review on articles written in English since the year 2010 until the present. Of course, although more research would be necessary to fully establish the type specificity of phenolics and their pharmacological activity, the evidence supports their potential as GABAAR modulators, thereby favoring their inclusion in the development of new therapeutic targets based on natural products. Specifically, the data compiled in this review allows for the directing of future research towards ortho-dihydroxy diterpene galdosol, the flavonoids isoliquiritigenin (chalcone), rhusflavone and agathisflavone (biflavonoids), as well as the phlorotannins, dieckol and triphlorethol A. Clinically, flavonoids are the most interesting phenolics due to their potential as anticonvulsant and anxiolytic drugs, and phlorotannins are also of interest as sedative agents
T cell leukemia control via Ras-Raf pathway inhibition with peptides
RATIONALE: RAS-RAF-MEK-ERK pathway has been considered a promising target for anticancer therapy. However, tumor cells may develop resistance against such drugs via hyperactivation of N-Ras, which explains why novel therapeut-ic approaches. In this sense, the Institute Curie- Université Pierre et Marie Curie (Paris 6) designed peptides in order to disturb Ras/Raf interaction which showed pro-apoptotic properties. These peptides were patented as WO2015001045 A2 (PCT/EP2014/064243)5.
OBJECTIVE: In order to check the anti-tumoral action of WO2015001045 A2 peptides in a very aggressive BALB/c mice spontaneous leukemia called LB, we performed the present study.
METHOD & RESULTS: 50 BALB/c mice inoculated with 106 LB tumor cells were randomly assigned either to control (placebo) or treatment group (that daily received 3 mg of peptide per kg of mice) during 30 days. By day 15 only 24% of the control group was alive vs. 100% of the treatment group. The average survival in treated group was 20,27 days while in control group the mean survival was 15,48 days. Either bone marrow, spleen or axillary nodes demonstrated a higher level of malignant T cell presence compare with treated group (89,78% ; 95,64% & 77,68% versus 72,45%, 80,23% & 63.44% respectively for each organ inspected.
DISCUSSION: Our study demonstrated an improvement in survival curves in mice model affected by spontaneous T lymphoid leukemia when peptides WO2015001045 A2 were used. These peptides might be a valid option to become part of the therapeutic armory for malignant lymphoproliferative diseases control.Facultad de Ciencias Médica
T cell leukemia control via Ras-Raf pathway inhibition with peptides
RATIONALE: RAS-RAF-MEK-ERK pathway has been considered a promising target for anticancer therapy. However, tumor cells may develop resistance against such drugs via hyperactivation of N-Ras, which explains why novel therapeut-ic approaches. In this sense, the Institute Curie- Université Pierre et Marie Curie (Paris 6) designed peptides in order to disturb Ras/Raf interaction which showed pro-apoptotic properties. These peptides were patented as WO2015001045 A2 (PCT/EP2014/064243)5.
OBJECTIVE: In order to check the anti-tumoral action of WO2015001045 A2 peptides in a very aggressive BALB/c mice spontaneous leukemia called LB, we performed the present study.
METHOD & RESULTS: 50 BALB/c mice inoculated with 106 LB tumor cells were randomly assigned either to control (placebo) or treatment group (that daily received 3 mg of peptide per kg of mice) during 30 days. By day 15 only 24% of the control group was alive vs. 100% of the treatment group. The average survival in treated group was 20,27 days while in control group the mean survival was 15,48 days. Either bone marrow, spleen or axillary nodes demonstrated a higher level of malignant T cell presence compare with treated group (89,78% ; 95,64% & 77,68% versus 72,45%, 80,23% & 63.44% respectively for each organ inspected.
DISCUSSION: Our study demonstrated an improvement in survival curves in mice model affected by spontaneous T lymphoid leukemia when peptides WO2015001045 A2 were used. These peptides might be a valid option to become part of the therapeutic armory for malignant lymphoproliferative diseases control.Facultad de Ciencias Médica
APOPTOTIC ACTIVITY OF BOSWELLIA CARTERII EXTRACT ON HUMAN NEUTROPHILS.
Neutrophil activation is required for the initiation of the defence mechanisms which include phagocytosis. Paradoxically, neutrophils also represent one of the main mediators of tissue injury in various human diseases. The resolution of inflammation requires getting rid of excess inflammatory cells through natural cell death and phagocyte clearance. Frankincense, an oleogum resin of different species of the genus Boswellia (Burseraceae), has long been used in eastern countries' traditional medicine to alleviate pain and inflammation. Although it was demonstrated that boswellic acids are potent activators of polymorphonuclear cells, little is known about the effects of the total extract on the human phagocytes’ apoptosis.
We here undertake a characterization of the Boswellia carteri resin extract (BCE) effects on human neutrophils activity and viability in vitro. Oxidative burst after stimulation with BCE was evaluated by reduction of nitroblue tetrazolium (NBT) colorimetric method for superoxide anion radical in the the presence of different compounds (N-ethyl maleimide, diltiazem, chelerythrine and wortmannin). Neutrophils viability was assessed by MTT. Flow analyses were performed with propidium iodide (PI) and annexin V-FITC.
Our results show that BCE induces the release reactive species of oxygen in human neutrophils in a dose dependent manner. The superoxide anion radical is principally produced via NADPH oxidase since inhibitors of the enzyme may prevent it. Ca+2 depletion reduce the magnitude of activation and PKC and PI3-K are also apparently involved in the process. The BCE has also cytotoxic activity revealed by the MTT assay. This effect seems to be produced by an apoptotic process as shown by the exclusion of the dye propidium iodide and the annexin V-FITC binding.
The capacity of the Boswellia carterii extract to accelerate the cellular death by an apoptotic process suggest that either the extract or its active compounds could have applications for the resolution of some inflammatory conditions
Design and validation of an instrument to evaluate metacognition on study in medicine students
Este artículo expone el diseño y la validación de un instrumento para evaluar la metacognición sobre procesos del estudio independiente en estudiantes de la Carrera de Medicina de la Facultad de Ciencias Médicas de la Universidad Nacional de La Plata, Argentina. El instrumento está conformado de 32 ítems escala Likert que examinan la percepción de si mismo, las acciones específicas y las formas de autoseguimiento en el estudio. Se complementa con una serie de preguntas abiertas. Los resultados muestran una estrecha asociación entre los tipos de conocimiento metacognitivo y once factores que gravitan en los distintos niveles de conciencia, las actividades de estudio y el rendimiento académico. Las dificultades detectadas en el estudio ponen en tensión la función de la enseñanza universitaria vinculada con la posibilidad de acceso por parte de los estudiantes al desarrollo de habilidades de alto nivel cognitivo en el estudio universitario y la inclusión educativa.This article discusses the design and validation of an instrument to evaluate the metacognition of independent study processes in students of the Medical Career of the Faculty of Medical Sciences of the National University of La Plata, Argentina. The instrument is composed of 32 Likert scale items that examine self-perception, specific activities and self-monitoring in the study. It is complemented by a series of open questions. The results show a close association between the types of metacognitive knowledge and eleven factors that influence the different levels of consciousness, study activities and academic performance. The difficulties detected in the study put in tension the role of university education linked to the possibility of access by students to the development of high level cognitive abilities in university study and educational inclusion.Facultad de Humanidades y Ciencias de la EducaciónFacultad de Ciencias Médica
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