Potential antitumor properties of a protein isolate obtained from the seeds of Amaranthus mantegazzianus

Background: Amaranth is a crop that can be grown in different soils and climates, being resistant to high temperatures, drought, and some pests. The amaranth plant has nutritional qualities and desirable biological properties. Aim of the study The aim of the study is to investigate the potential antitumor properties of Amaranthus-mantegazzianus-protein isolate (MPI) and to elucidate the possible mechanism of action. Methods: We use four different tumor-derived and in vitro-transformed cell lines with different morphology and tumorigenicity (MC3T3E1, UMR106, Caco-2, and TC7). Results: The MPI showed an antiproliferative effect on four cell lines with different potencies. The tumor-cell line UMR106 was the most sensitive (IC50: 1 mg/ml). This antiproliferative effect of the MPI was enhanced by protease treatment (IC50: 0.5 after 30% hydrolysis). In addition, the MPI produced morphological changes and caused a rearrangement of the cytoskeleton in UMR106 cell line. In an attempt to elucidate the mechanism of action, we observed that the MPI inhibited cell adhesion and induced apoptosis and necrosis in the UMR106 cell line. In reversibility studies, we were able to observe both temporary and permanent cytostatic and cytotoxic effects on the part of the MPI, depending on its concentration. Conclusions: we report a protein isolate from the seeds of Amaranthus mantegazzianus that exhibit potential antitumor properties and propose a putative mechanism of action.Fil: Barrio, Daniel Alejandro. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

Farmacología de compuestos de vanadio: efectos sobre células osteoblásticas en cultivo

Objetivos generales • Sintetizar e identificar diversos compuestos de vanadio con ligandos de interés biológico y farmacológico. • Evaluar el efecto de los compuestos de vanadio(IV) sobre la actividad específica de diferentes fosfatasas. • Estudiar los efectos biológicos de los derivados de vanadio sobre células osteoblásticas en cultivo. • Seleccionar complejos de vanadio(IV) con potencial aplicación farmacológica. • Investigar el mecanismo de acción de los complejos de vanadio(IV) seleccionados. Objetivos específicos: • Sintetizar e identificar complejos del catión vanadilo(IV) con azúcares simples y compuestos relacionados. • Estudiar el efecto inhibitorio de los complejos del catión vanadilo(IV) sobre la actividad específica de fosfatasa alcalina de origen intestinal y óseo. • Evaluar los efectos de los complejos de vanadio(IV) sobre la proliferación, diferenciación, consumo de glucosa, morfología celular y citotoxicidad de células osteoblásticas en cultivo. • Seleccionar complejos de vanadio(IV) con actividad insulinomimética y antitumoral. • Estudiar el efecto de los complejos de vanadio(IV) con potencial aplicación farmacológica sobre las diferentes etapas del desarrollo osteoblástico. • Investigar los posibles mecanismos de acción implicados en algunos de los efectos biológicos y farmacológicos de los complejos seleccionados.Tesis digitalizada en SEDICI gracias a la Biblioteca Central de la Facultad de Ciencias Exactas (UNLP).Facultad de Ciencias Exacta

Chemical and Biological Characterization from Condalia microphylla Fruits, a Native Species of Patagonia Argentina

Condalia microphylla Cav. (Rhamnaceae), popularly known as “piquillin”, is widely distributed in Patagonia. The drupes are consumed as fresh fruits by Argentine communities. The aim of this work was to quantify the nutritional value of C. microphylla fruit and the phenolic compounds present and to determine the functional antioxidant properties in vitro and in vivo. The nutritional value was determined according to the Association of Official Analytical Chemists (AOAC) methodology, and phenolic compounds were quantified by diode-array detection (HPLC-DAD). Antioxidant activity in vitro and in vivo was analyzed through the use of the radical species 2,2-diphenyl-1-picrylhydrazyl (DPPH) and zebrafish model, respectively. Quercetin-3-O-rutinoside (rutin) was the single principal phenolic compound. The extracts contained in vitro antioxidant activities and total phenolic contents (TPCs) between 1,143 ± 112 µg and 4,633 ± 174 µg gallic-acid equivalents (GAEs) per 100 g dry weight (DW), though no relationship was found between the latter parameter and the antioxidant activity of the extracts. When zebrafish larvae were exposed to oxidative stress (2.4% v/v H2O2), a concentration as low as 1.44 µg of GAEs/mL of piquillin-derived polyphenols inhibited lipid oxidation by up to 40%. Thus, in view of these advantageous functional food properties and the opportunity to exploit this Patagonian natural resource, piquillin consumption should be promoted worldwide.Fil: Boeri, Patricia. Universidad Nacional de Río Negro. Sede Atlántica; ArgentinaFil: Piñuel, Maria Lucrecia. Universidad Nacional de Rio Negro. Centro de Investigaciones y Transferencia de Rio Negro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Rio Negro; Argentina. Universidad Nacional de Río Negro. Sede Atlántica; ArgentinaFil: Sharry, Sandra Elizabeth. Universidad Nacional de Río Negro. Sede Atlántica; Argentina. Universidad Nacional de la Plata. Facultad de Cs.agrarias y Forestales. Departamento de Tecnología Agropecuaria y Forestal. Centro Exptal.de Propagación Vegetativa; ArgentinaFil: Tombari, Andrea Diana. Universidad Nacional de Río Negro. Sede Atlántica; ArgentinaFil: Barrio, Daniel Alejandro. Universidad Nacional de Río Negro. Sede Atlántica; Argentina. Universidad Nacional de Rio Negro. Centro de Investigaciones y Transferencia de Rio Negro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Rio Negro; Argentin

Development of a new zebrafish (Danio Rerio) model bioassay for detection of marine biotoxins in bivalve shellfish

La extracción, producción y procesamiento de moluscos bivalvos presenta un inconveniente para la calidad e inocuidad agroalimentaria, dado que pueden estar contaminados con toxinas marinas. El consumo de mariscos contaminados con dichas sustancias provoca intoxicaciones graves y constituye un problema para la salud de la población. Por eso, es necesario contar con un método rápido, sensible y específico para determinar su presencia. El bioensayo en ratón, establecido como método oficial por la asociación de comunidades analíticas –Association of Analytical Communities (AOAC 2012)–, es el utilizado; sin embargo la polémica en torno al uso de mamíferos en ensayos, sumada a los problemas y limitaciones inherentes a su realización, han impulsado el desarrollo de otros métodos. El objetivo de este proyecto es desarrollar un bioensayo para la detección de biotoxinas marinas en moluscos bivalvos empleando el modelo del pez cebra. El embrión del pez cebra (Danio rerio) es ampliamente utilizado como modelo vertebrado de estudio para ensayos toxicológicos. Este sistema se aplica cada vez más para el estudio de toxinas marinas. Las ventajas del modelo son la simplicidad y economía de mantenimiento y reproducción y el bajo cuestionamiento social a su uso. Para el desarrollo del bioensayo se realizarán curvas dosis-respuesta con extractos de moluscos bivalvos con toxina y sin ella evaluados previamente por el método del ratón y por cromatografía líquida de alto desempeño (HPLC). Se determinará la dosis letal mediana (DL50) y los cambios morfológicos producidos por la toxina a fin de establecer los parámetros y condiciones del ensayo. Una vez definido un protocolo de trabajo, se validará (selectividad, linealidad, sensibilidad, límites, rango, precisión, veracidad, robustez y aplicabilidad) y contrastará con el ensayo del ratón y los resultados de la HPLC. La instalación de este modelo vertebrado en los laboratorios de toxicología permitiría adicionalmente la adopción de nuevas técnicas para la realización de ensayos toxicológicos en alimentos, aguas residuales y otras matrices.Shellfish extraction, production and processing poses an inconvenience for quality and food safety, because the product may be contaminated with marine toxins. The consumption of toxin-contaminated shellfish produces severe poisoning, being a problem for the human health. That is why it is necessary to have a rapid, sensitive and specific method to determine the presence of these substances. The mouse bioassay is the standard method (AOAC 2012), but the controversy around the use of mammals in testing, and the problems and limitations of its implementation, has promoted the development of new methods. The aim of this project is to develop a bioassay for detecting marine toxins in shellfish using the zebrafish model. The zebrafish (Danio rerio) embryo is widely used as a vertebrate model for toxicological studies. This system is increasingly applied to the study of marine toxins. The advantages of the model are the simplicity and economy of its maintenance and reproduction, and the low social opposition to its use. To develop the bioassay, we will perform doseresponse curves with shellfish extracts –with and without toxin– previously evaluated by both the mouse method and HPLC. The lethal dose (LD50) and the morphological changes produced by the toxin will be determined in order to establish test parameters and conditions. Then, we will define a working protocol and it must be validated (selectivity, linearity, specificity, limits, range, precision, accuracy, robustness and applicability) and contrast with the mouse assay and HPLC results. The incorporation of this model by toxicology laboratories, additionally allows the adoption of new techniques for toxicological testing of food, sewage and other matrices.Fil: Fellenz, Nicolás Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rio Negro. Sede Atlantica; ArgentinaFil: Piñuel, Lucrecia. Universidad Nacional de Rio Negro. Sede Atlantica; ArgentinaFil: Boeri, Patricia. Universidad Nacional de Rio Negro. Sede Atlantica; ArgentinaFil: Fernández, Carolina. Universidad Nacional de Rio Negro. Sede Atlantica; ArgentinaFil: Barrio, Natalia. Universidad Nacional de Rio Negro. Sede Atlantica; ArgentinaFil: Barrio, Daniel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Rio Negro. Sede Atlantica; Argentin

Osteogenic activity of vanadyl(IV)-ascorbate complex: evaluation of its mechanism of action

We have previously shown that different vanadium(IV) complexes regulate osteoblastic growth. Since vanadium compounds are accumulated in vivo in bone, they may affect bone turnover. The development of vanadium complexes with different ligands could be an alternative strategy of use in skeletal tissue engineering. In this study, we have investigated the osteogenic properties of a vanadyl(IV)–ascorbate (VOAsc) complex, as well as its possible mechanisms of action, on two osteoblastic cell lines in culture. VOAsc (2.5–25 M) significantly stimulated osteoblastic proliferation (113–125% basal, p < 0.01) in UMR106 cells, but not in the MC3T3E1 cell line. VOAsc (5–100 M) dose-dependently stimulated type-I collagen production (107–156% basal) in osteoblasts. After 3 weeks of culture, 5–25 M VOAsc increased the formation of nodules of mineralization in MC3T3E1 cells (7.7–20-fold control, p < 0.001). VOAsc (50–100 M) significantly stimulated apoptosis in both cell lines (170–230% basal, p < 0.02–0.002), but did not affect reactive oxygen species production. The complex inhibited alkaline and neutral phosphatases from osteoblastic extracts with semi-maximal effect at 10 M doses. VOAsc induced the activation and redistribution of P-ERK in a time- and dose-dependent manner. Inhibitors of the mitogen activated protein kinases (MAPK) pathway (PD98059 and UO126) partially blocked the VOAsc-enhanced osteoblastic proliferation and collagen production. In addition, wortmanin, a PI-3-K inhibitor and type-L channel blocker nifedipine also partially abrogated these effects of VOAsc on osteoblasts. Our in vitro results suggest that this vanadyl(IV)–ascorbate complex could be a useful pharmacological tool for bone tissue regeneration.Facultad de Ciencias Exacta

Potential antitumor properties of a protein isolate obtained from the seeds of <i>Amaranthus mantegazzianus</i>

Background: Amaranth is a crop that can be grown in different soils and climates, being resistant to high temperatures, drought, and some pests. The amaranth plant has nutritional qualities and desirable biological properties. Aim of the study: The aim of the study is to investigate the potential antitumor properties of Amaranthus-mantegazzianus-protein isolate (MPI) and to elucidate the possible mechanism of action. Methods: We use four different tumor-derived and in vitro-transformed cell lines with different morphology and tumorigenicity (MC3T3E1, UMR106, Caco-2, and TC7). Results: The MPI showed an antiproliferative effect on four cell lines with different potencies. The tumor-cell line UMR106 was the most sensitive (IC₅₀: 1 mg/ml). This antiproliferative effect of the MPI was enhanced by protease treatment (IC₅₀: 0.5 after 30% hydrolysis). In addition, the MPI produced morphological changes and caused a rearrangement of the cytoskeleton in UMR106 cell line. In an attempt to elucidate the mechanism of action, we observed that the MPI inhibited cell adhesion and induced apoptosis and necrosis in the UMR106 cell line. In reversibility studies, we were able to observe both temporary and permanent cytostatic and cytotoxic effects on the part of the MPI, depending on its concentration. Conclusions: we report a protein isolate from the seeds of Amaranthus mantegazzianus that exhibit potential antitumor properties and propose a putative mechanism of action.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Spectroscopic Characterization of a VO²⁺ Complex of Oxodiacetic Acid and its Bioactivity on Osteoblast-like Cells in Culture

The oxovanadium(IV) complex of oxodiacetic acid (H₂oda) of stoichiometry [VO(oda)(H₂O)₂], which presents an unprecedented tridentate OOO coordination, was thoroughly characterized by infrared, Raman, electronic, and electron paramagnetic resonance spectroscopies. The biological activity of the complex on the cell proliferation and differentiation was tested on osteoblast-like cells (MC3T3E1 osteoblastic mouse calvaria-derived cells and UMR106 rat osteosarcoma-derived cells) in culture. The complex caused inhibition of cellular proliferation in both osteoblast-like cells in culture, but the cytotoxicity was stronger in the normal (MC3T3E1) than in the tumoral (UMR106) osteoblasts. The effect of the complex in cell differentiation was tested through the specific activity of alkaline phosphatase of the UMR106 cells because they expressed a high activity of this enzyme. What occurs with other vanadium compounds [VO(oda)(H₂O)₂] is an inhibitory agent of osteoblast differentiation.Facultad de Ciencias ExactasCentro de Química Inorgánic

Osteogenic activity of vanadyl(IV)-ascorbate complex: evaluation of its mechanism of action

We have previously shown that different vanadium(IV) complexes regulate osteoblastic growth. Since vanadium compounds are accumulated in vivo in bone, they may affect bone turnover. The development of vanadium complexes with different ligands could be an alternative strategy of use in skeletal tissue engineering. In this study, we have investigated the osteogenic properties of a vanadyl(IV)–ascorbate (VOAsc) complex, as well as its possible mechanisms of action, on two osteoblastic cell lines in culture. VOAsc (2.5–25 M) significantly stimulated osteoblastic proliferation (113–125% basal, p < 0.01) in UMR106 cells, but not in the MC3T3E1 cell line. VOAsc (5–100 M) dose-dependently stimulated type-I collagen production (107–156% basal) in osteoblasts. After 3 weeks of culture, 5–25 M VOAsc increased the formation of nodules of mineralization in MC3T3E1 cells (7.7–20-fold control, p < 0.001). VOAsc (50–100 M) significantly stimulated apoptosis in both cell lines (170–230% basal, p < 0.02–0.002), but did not affect reactive oxygen species production. The complex inhibited alkaline and neutral phosphatases from osteoblastic extracts with semi-maximal effect at 10 M doses. VOAsc induced the activation and redistribution of P-ERK in a time- and dose-dependent manner. Inhibitors of the mitogen activated protein kinases (MAPK) pathway (PD98059 and UO126) partially blocked the VOAsc-enhanced osteoblastic proliferation and collagen production. In addition, wortmanin, a PI-3-K inhibitor and type-L channel blocker nifedipine also partially abrogated these effects of VOAsc on osteoblasts. Our in vitro results suggest that this vanadyl(IV)–ascorbate complex could be a useful pharmacological tool for bone tissue regeneration.Facultad de Ciencias Exacta

Synthesis of a new vanadyl(IV) complex with trehalose (TreVO): insulin-mimetic activities in osteoblast-like cells in culture

Vanadium compounds show interesting biological and pharmacological properties. Some of them display insulin-mimetic effects and others produce antitumor actions. The bioactivity of vanadium is present in inorganic species like the vanadyl(IV) cation or vanadate( V) anion. Nevertheless, the development of new vanadium derivatives with organic ligands which improve the beneficial actions and decrease the toxic effects is of great interest. On the other hand, the mechanisms involved in vanadium bioactivity are still poorly understood. A new vanadium complex of the vanadyl(IV) cation with the disaccharide trehalose (TreVO), Na6 [VO(Tre)2].4H2O, here reported, shows interesting insulin- mimetic properties in two osteoblast cell lines, a normal one (MC3T3E1) and a tumoral one (UMR106). The complex affected the proliferation of both cell lines in a different manner. On tumoral cells, TreVO caused a weak stimulation of growth at 5 lM but it inhibited cell proliferation in a dose-response manner between 50 and 100 lM. TreVO significantly inhibited UMR106 differentiation (15–25% of basal) in the range 5–100 lM. On normal osteoblasts, TreVO behaved as a mitogen at 5–25 lM. Different inhibitors of the MAPK pathway blocked this effect. At higher concentrations (75–100 lM), the complex was a weak inhibitor of the MC3T3E1 proliferation. Besides, TreVO enhanced glucose consumption by a mechanism independent of the PI3-kinase activation. In both cell lines, TreVO stimulated the ERK phosphorylation in a dose- and time-dependent manner. Different inhibitors (PD98059, wortmannin, vitamins C and E) partially decreased this effect, which was totally inhibited by their combination. These results suggest that TreVO could be a potential candidate for therapeutic treatments.Facultad de Ciencias Exacta

Synthesis of a new vanadyl(IV) complex with trehalose (TreVO): insulin-mimetic activities in osteoblast-like cells in culture

Vanadium compounds show interesting biological and pharmacological properties. Some of them display insulin-mimetic effects and others produce antitumor actions. The bioactivity of vanadium is present in inorganic species like the vanadyl(IV) cation or vanadate( V) anion. Nevertheless, the development of new vanadium derivatives with organic ligands which improve the beneficial actions and decrease the toxic effects is of great interest. On the other hand, the mechanisms involved in vanadium bioactivity are still poorly understood. A new vanadium complex of the vanadyl(IV) cation with the disaccharide trehalose (TreVO), Na6 [VO(Tre)2].4H2O, here reported, shows interesting insulin- mimetic properties in two osteoblast cell lines, a normal one (MC3T3E1) and a tumoral one (UMR106). The complex affected the proliferation of both cell lines in a different manner. On tumoral cells, TreVO caused a weak stimulation of growth at 5 lM but it inhibited cell proliferation in a dose-response manner between 50 and 100 lM. TreVO significantly inhibited UMR106 differentiation (15–25% of basal) in the range 5–100 lM. On normal osteoblasts, TreVO behaved as a mitogen at 5–25 lM. Different inhibitors of the MAPK pathway blocked this effect. At higher concentrations (75–100 lM), the complex was a weak inhibitor of the MC3T3E1 proliferation. Besides, TreVO enhanced glucose consumption by a mechanism independent of the PI3-kinase activation. In both cell lines, TreVO stimulated the ERK phosphorylation in a dose- and time-dependent manner. Different inhibitors (PD98059, wortmannin, vitamins C and E) partially decreased this effect, which was totally inhibited by their combination. These results suggest that TreVO could be a potential candidate for therapeutic treatments.Facultad de Ciencias Exacta