Establecimiento de condiciones óptimas para obtener un aislado proteico de avellana chilena (Gevuina avellana, Mol)

Una alternativa para resolver el problema del déficit global de proteínas ha sido la utilización de tortas desgrasadas generadas por la extracción de aceite de fuentes vegetales tales como raps, soya, lupino, etc, proceso que al mismo tiempo incrementa el contenido proteico, siendo factible que sea usada para enriquecer algunos tipos de alimentos. Tal es el caso de la avellana chilena (Gevuina avellana, Mol), especie monotípica caracterizada por su elevado porcentaje de aceite (50%) y cuya torta desgrasada podría utilizarse para obtener un aislado proteico. Con este fin se optimizaron las condiciones de extracción de proteína utilizando para ello la metodología superficie de respuesta (MSR) seleccionando el diseño central compuesto, tres variables independientes: tiempo de contacto de la torta con el solvente, relación muestra/solvente y pH, con 5 niveles de trabajo cada uno y tres replicaciones en el punto central. Los datos fueron sometidos a un análisis de regresión y después de ANOVA. El primero para determinar la ecuación polinómica y el segundo para seleccionar los factores de control con efecto significativo sobre el rendimiento de la proteína. La mejor combinación de los factores resultó ser tiempo entre 30 y 40 minutos, pH entre 9 y 9,5 y la relación muestra/ solvente entre 1/15 a 1/16, con un rendimiento final de 76%. En cuanto a las características físicas esta fueron: densidad aparente 0,504 g/cm3, compactación 43,34% y color amarillo claro. El análisis proximal mostró una concentración de proteínas de 76%, hidratos de carbono 13%, fibra cruda 0,68% y aceite 1,29%. En cuanto a las propiedades funcionales destacó absorción de agua (320 g/100 g), absorción de aceite (410 g/100g) y capacidad espumante (221, 05 %).

Establishment of optimun conditions in order to obtain a protein isolate from Chilean Hazelnut. An alternative to solve the problem of the overall deficit of proteins has been the use of defatted cakes generated by the extraction of oil from vegetable sources such as rapeseed, soybean, lupin, etc. This process at the same time increases the protein content, making this feasible to be used to enrich some types of food. This is the case of the chilean hazelnut (Gevuina avellana, Mol), monotypic species characterized by their high percentage of oil (50%) and whose defatted cake isolated protein could be used to obtain an isolated protein. For this purpose optimized conditions of extraction of protein were carried out using the surface response methodology (SRM) and a central composite design with three independent variables: time of contact of the cake with the solvent, sample /solvent ratio and pH was used. All variables were controlled at five different levels. The data were subjected to an analysis of regression and ANOVA, the first to determine the polynomial equation and the second to select the control factors with significant effect on the extraction of the protein. The best combination of factors turned out to be: time between 30 and 40 minutes, pH between 9 and 9.5 and a relationship sample / solvent between 1/15 to 1/16 with a final yield of 76%. The physical characteristics were: density 0,504 g/cm3, compaction 43, 34 % apparent and pale yellow. Proximal analysis showed a concentration of protein of 76%, 13%, raw fiber carbohydrate 0.68% and oil 1.29%. With regard to the functional properties emphasized water absorption (320 g / 100 g), absorption of oil (410 g / 100 g) and foaming capacity (221 %).

[Establishment of optimun conditions in order to obtain a protein isolate from Chilean Hazelnut]. / Establecimiento de condiciones optimas para obtener un aislado proteico de avellana chilena (Gevuina avellana, Mol).

An alternative to solve the problem of the overall deficit of proteins has been the use ofdefatted cakes generated by the extraction of oil from vegetable sources such as rapeseed, soybean, lupin, etc. This process at the same time increases the protein content, making this feasible to be used to enrich some types of food. This is the case of the chilean hazelnut (Gevuina avellana, Mol), monotypic species characterized by their high percentage of oil (50%) and whose defatted cake isolated protein could be used to obtain an isolated protein. For this purpose optimized conditions of extraction of protein were carried out using the surface response methodology (SRM) and a central composite design with three independent variables: time of contact of the cake with the solvent, sample/solvent ratio and pH was used. All variables were controlled at five different levels. The data were subjected to an analysis of regression and ANOVA, the first to determine the polynomial equation and the second to select the control factors with significant effect on the extraction of the protein. The best combination of factors turned out to be: time between 30 and 40 minutes, pH between 9 and 9.5 and a relationship sample/solvent between 1/15 to 1/16 with a final yield of 76%. The physical characteristics were: density 0,504 g/cm3, compaction 43, 34% apparent and pale yellow. Proximal analysis showed a concentration of protein of 76%, 13%, raw fiber carbohydrate 0.68% and oil 1.29%. With regard to the functional properties emphasized water absorption (320 g/100 g), absorption of oil (410 g/100 g) and foaming capacity (221%).

Protection against Plasmodium falciparum challenge induced in Aotus monkeys by liver-stage antigen-3-derived long synthetic peptides.

The vaccine potential of Plasmodium falciparum liver stage antigen-3 (LSA3) was investigated in Aotus monkeys using two long synthetic peptides corresponding respectively to an N-terminal non-repeat peptide (NRP) and repeat 2 (R2) region of the LSA3, adjuvanted by ASO2. Both 100-222 (NRP) and 501-596 repeat peptides induced effector B- and T-cell responses in terms of antigen-driven antibodies and/or specific IFN-gamma secretion. Animals challenged with P. falciparum sporozoites were protected following immunization with either the NRP region alone or the NRP combined with the R2 repeat region, as compared with controls receiving the adjuvant alone. These results indicate that the NRP may be sufficient to induce full, sterile protection and confirm the vaccine potential of LSA3 previously demonstrated in chimpanzees and in Aotus.

Effect of Solanum nudum Dunal (Solanaceae) steroids on hepatic trophozoites of Plasmodium vivax.

Steroids isolated from the plant Solanum nudum showed antiplasmodial activity against the blood stages of Plasmodium falciparum. It has been demonstrated that these steroids are neither mutagenic in vitro nor clastogenic in vivo. This study evaluated the effect of five steroids of S. nudum (SN-1, SN-2, SN-3, SN-4 and SN-5) on hepatic trophozoites of P. vivax, using an experimental design, non-balanced, with blind determination of the effect expressed as the percentage reduction of hepatic trophozoites. The sporozoites used to inoculate human hepatoma cells HepG2-A16 were obtained from gametocytemic blood of volunteers infected only with P. vivax, and passed into laboratory-reared Anopheles albimanus mosquitoes. Steroids were added at three different doses (100, 10 and 1 microg/mL) just after inoculation of the cells with sporozoites. The effect was determined by indirect immunofluorescence assays using the monoclonal antibodies Pv210 or Pv47E-2E10 and steroid cytotoxicity on HepG2-A16 cells was assessed by the MTT method. All the steroids reduced the number of hepatic P. vivax trophozoites, SN-2 and SN-4 reduced the number of hepatic trophozoites by 47% and 39% (p < 0.05), respectively.

Proceso para el desarrollo de una vacuna contra la fase hepática de Plasmodium vivax / Process to development a vaccine against to hepatic phase of Plasmodium vivax

Introducción: Anualmente se producen en el mundo entre 80 y 100 millones de casos de malaria ocasionada por Plasmodium vivax, segunda especie de Plasmodium en importancia a nivel mundial y primera en el continente americano. Ante la falla de los métodos clásicos de control de la malaria, derivada de la creciente resistencia de los mosquitos a los insecticidas y de los parásitos a los medicamentos disponibles, se ha trabajado intensamente en la búsqueda de vacunas que puedan prevenir completamente la infección o limitar los efectos patológicos de la enfermedad. Objetivos: Este trabajo describe el proceso de desarrollo de una vacuna experimental dirigida contra las formas pre-eritrocíticas del parásito, para lo cual se ha seleccionado la proteína circumesporozoito (CS) que se expresa de forma abundante en la superficie del parásito y que se halla comprometida en el proceso de invasión hepática. Metodología: El proceso consistió en una exhaustiva caracterización inmunológica de la proteína, mediante péptidos sintéticos de diferente longitud, seguida de pruebas de toxicidad e inmunogenicidad en animales con los tres péptidos largos que cubren las regiones N, R y C de la CS. Como etapa inicial de la prueba en humanos, se hizo un ensayo clínico fase I que probó la seguridad e inmunogenicidad, de cada uno de los péptidos formulados en el adyuvante Montanide ISA-720. El ensayo fue al azar, doble ciego y comprometió a 23 voluntarios sanos, hombres y mujeres entre 18 y 33 años de edad, sin historia de malaria. Conclusiones: La vacuna fue muy bien tolerada y demostró buena seguridad e inmunogenicidad en los ensayos preclínicos así como en todos los voluntarios, facilitando el avance a ulteriores fases de investigaciónclinica

Immunogenicity and protective efficacy of Plasmodium falciparum liver-stage Ag-3 in Aotus lemurinus griseimembra monkeys.

Three recombinant proteins spanning the Plasmodium falciparum liver-stage Ag-3 (LSA-3) were used to immunize Aotus monkeys. The proteins were delivered subcutaneously without adjuvant, adsorbed onto polystyrene 0.5 microm particles at a concentration of 2 microg per immunization. Control animals received glutathione-S-transferase formulated similarly. Animals were challenged as late as 5 months after the last immunization, by intravenous inoculation of 100,000 P. falciparum sporozoites of a strain heterologous to the one from which the immunogens were derived. Sterile protection was achieved in three of the five immunized monkeys but in none of four controls. Antibodies were at low titer, but reacted with the native parasite protein and were boosted by parasite challenge. Ag-specific IFN-gamma secretion was detectable in all LSA-3-immunized animals in response to the LSA-3-derived Ag. The protection was apparently associated with high levels of IFN-gamma production in response to in vitro recall Ag. These results lend support to the vaccine potential of LSA-3 indicated by previous results obtained in chimpanzees, as well as the value of yet another Ag-delivery system. They also support the value of the Aotus model for the pre-clinical development of pre-erythrocytic-stage vaccines.

Serum factors inhibitory for in vitro development of Plasmodium falciparum blood-stage parasites

Sera from 29 individuals residing in a malaria-endemic region of Colombia were evaluated by an inhibition assay for their capacity to retard the growth of Plasmodium falciparum in vitro. The inhibitory activity was found to be independent of antibody activity. Furthermore, the degree of inhibition of parasite development was variable, depending on the parasite isolate used for the assay and the season of malaria transmission. We selected sera with high inhibitory activity and carried out partial analytical characterization by anion exchange fast protein liquid chromatography (FPLC) to identify the chemical nature of the inhibitory factor(s). The results suggested that the in vitro inhibitory activity might result from the additive effect of different molecules. It appears that these molecules could be non-specifically induced by stimulation of the immune system, they seem to play a role in the immunity to malaria.