Avaliação da capacidade antioxidante de extractos naturais de maçã e azeitona usando modelos celulares em monocamada (2D) e agregados (3D)
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2014
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Actualmente, os compostos bioactivos de alimentos têm vindo a ser comercializados na forma de produtos farmacêuticos, cosméticos e aditivos alimentares, reclamando efeito benéfico na saúde. Para o desenvolvimento e comercialização destes produtos é necessário a avaliação das propriedades biológicas. Este trabalho teve como objectivo a avaliação da capacidade antioxidante e neuroprotectora de extractos naturais de maçã e azeitona utilizando ensaios pré-clinicos, nomeadamente métodos químicos e modelos celulares em 2D e 3D. Foram analisados 11 extractos de maçã (variedade Bravo de Esmolfe) obtidos por diferentes tecnologias. A extracção com fluídos pressurizados (EFP) demonstrou ser mais eficiente do que a extracção convencional em termos de rendimento e de compostos extraídos. As condições de EFP 60:40:0 e 90:5:5 (v/v CO2:EtOH:H2O) permitiram obter fracções com maior concentração em compostos antioxidantes e maior capacidade de resgate de radicais livres (EROs) no modelo celular Caco-2, respectivamente. Os principais compostos responsáveis pela actividade antioxidante foram: epicatequina, glucósidos de quercetina e procianidina B2. Para o extracto de bagaço de azeitona, rico em hidroxitirosol, foi demonstrada a capacidade de resgate de EROs e de prevenção da morte celular em agregados de células NT2 diferenciadas em neurónios, sendo que este efeito neuroprotector foi superior ao obtido para o composto puro.
Nowadays, bioactive compounds from foods have been commercialized as pharmaceuticals, cosmetics and food additives products, claiming health promoting effects. For the development of these products the evaluation of their biological properties is required. The main aim of this work was the evaluation of antioxidant and neuroprotective effect of apple and olive natural extracts using preclinical assays, namely chemical methods and cellular models in 2D and 3D. Eleven extracts obtained by different technologies from ‘Bravo de Esmolfe’ apple variety were analyzed. High pressure extraction (HPE) proved to be more efficient in yield and extracted compounds than conventional method. The solvent ratio of 60:40:0 and 90:5:5 (v/v CO2:EtOH:H2O) allowed to obtain fractions with the highest concentration of antioxidants and increased ability in scavenging free radicals (ROS) in Caco-2 cell model, respectively. Epicatechin, quercetin glycosides and procyanidin B2 were identified as the main compounds responsible for the antioxidant of samples. The olive mill residues extract rich in hydroxytyrosol, demonstrated ability to scavenge ROS and prevent death of neurons derived from NT2 cells cultured as aggregates. This neuroprotective effect was superior to that obtained for the pure compound.
Nowadays, bioactive compounds from foods have been commercialized as pharmaceuticals, cosmetics and food additives products, claiming health promoting effects. For the development of these products the evaluation of their biological properties is required. The main aim of this work was the evaluation of antioxidant and neuroprotective effect of apple and olive natural extracts using preclinical assays, namely chemical methods and cellular models in 2D and 3D. Eleven extracts obtained by different technologies from ‘Bravo de Esmolfe’ apple variety were analyzed. High pressure extraction (HPE) proved to be more efficient in yield and extracted compounds than conventional method. The solvent ratio of 60:40:0 and 90:5:5 (v/v CO2:EtOH:H2O) allowed to obtain fractions with the highest concentration of antioxidants and increased ability in scavenging free radicals (ROS) in Caco-2 cell model, respectively. Epicatechin, quercetin glycosides and procyanidin B2 were identified as the main compounds responsible for the antioxidant of samples. The olive mill residues extract rich in hydroxytyrosol, demonstrated ability to scavenge ROS and prevent death of neurons derived from NT2 cells cultured as aggregates. This neuroprotective effect was superior to that obtained for the pure compound.
Descrição
Orientação: Ana Teresa de Carvalho Negrão Serra ; co-orientação: Maria Margarida de Carvalho Negrão Serra
Palavras-chave
ENGENHARIA BIOTECNOLÓGICA, BIOTECHNOLOGY ENGINEERING, FITOQUÍMICA, PLANT CHEMISTRY, ANTIOXIDANTES, ANTIOXIDANTS, CÉLULAS, CELLS, FRUTOS COMESTÍVEIS, EDIBLE FRUIT, MESTRADO EM ENGENHARIA BIOTECNOLÓGICA