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Caracterização fitoquímica da pitaia (Hylocereus sp.): estudo das propriedades antioxidantes, anti-hiperglicémicas e anti-inflamatórias
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Doenças crónicas não transmissíveis são uma das principais causas de morte prematura em todo o mundo, tais como diabetes, doenças cardiovasculares e cancro. Na base do desenvolvimento destas doenças há fatores de risco que podem ser controlados. Um deles é a alimentação. Alimentações muito calóricas, ricas em açúcares e gordura, principalmente saturada favorecem o desenvolvimento destas doenças. Por outro lado, existem alimentos que contêm compostos com efeitos antioxidantes e anti-inflamatórios, capazes de prevenir estas doenças, ou pelo menos retardar o seu desenvolvimento. A procura desses alimentos tem sido uma preocupação nos últimos tempos.
A pitaia, fruto ainda pouco conhecido pela população da Europa, começa a ser descrito como sendo uma fonte de compostos com propriedades funcionais capazes de prevenir o desenvolvimento de algumas doenças. Como exemplo desses compostos podem citar-se algumas vitaminas e compostos fenólicos com ações fisiológicas importantes na prevenção de algumas doenças crónicas.
O objetivo deste trabalho é caracterizar fitoquimicamente o extrato de pitaia vermelha (Hylocereus costaricensis) e avaliar as suas atividades antioxidante, anti-hiperglicémica e anti-inflamatória.
Foram encontrados 165,8 ± 0,8 mg EAG/100 g de fruto fresco de fenóis totais e 110,1 ± 0,6 mg EC/100 g de fruto fresco de flavonóides no extrato obtido com água que foi o reagente de extração que mostrou ter maior rendimento. Utilizando o método de HPLC-DAD-MS/MS foi possível identificar no extrato de pitaia compostos como o ácido cítrico, ácido succínico, ácido ferúlico, cianidina-3-o-rutinósido, rutina, filocactina e betanina.
A atividade antioxidante do extrato de pitaia foi avaliada pelo método DPPH, e apresentou uma capacidade de eliminação de radicais livres de 33,4%; e pelo método in vitro de produção intracelular de espécies reativas de oxigénio em células HaCaT, onde o extrato de pitaia de 10 mg/mL mostrou uma capacidade de redução de espécies reativas de oxigénio causadas pelo stress oxidativo por luz ultravioleta, de 95%. Estes resultados indicam que o extrato tem um potencial antioxidante.
Para avaliação da atividade anti-hiperglicémica foi utilizado um modelo animal de indução hiperglicémica com uma sobrecarga de glucose. A administração do extrato na dose de 10 mg EAG/kg durante 15 dias, antes da sobrecarga com a glucose, mostrou atividade anti-hiperglicémica.
Para avaliação da atividade anti-inflamatória foi utilizado o modelo animal de inflamação local aguda, induzida pela carragenina. A administração de extratos na dose 5 mg EAG/kg e 10 mg EAG/kg durante 15 dias, mostrou ter atividade anti-inflamatória, já que os compostos fenólicos do extrato foram capazes de reduzir o edema causado pela carragenina. Foi possível verificar uma maior eficácia na diminuição do edema com a dose mais concentrada (10 mg EAG/kg) do extrato, o que sugere que o efeito anti-inflamatório é dependente da dose.
Os nossos resultados sugerem assim que o extrato fenólico de pitaia, pode ter um papel importante na proteção da saúde humana quando incorporado na dieta. Uma vez que foi capaz de apresentar propriedades antioxidantes, anti-hiperglicémicas e anti-inflamatórias.
Chronic non-communicable diseases are one of the main causes of premature death worldwide, such as diabetes, cardiovascular disease, and cancer. At the root of the development of these diseases are risk factors that can be controlled. One of them is diet. High-calorie foods, high in sugar and fat, especially saturated fat, favor the development of these diseases. On the other hand, there are foods that contain compounds with antioxidant and anti-inflammatory effects, capable of preventing these diseases, or at least slowing down their development. The search for these foods has been a concern recently. Dragon fruit, a fruit that is still little known to the European population, is beginning to be described as a source of compounds with functional properties that can prevent the development of certain diseases. Examples of these compounds include some vitamins and phenolic compounds with important physiological actions in the prevention of some chronic diseases. The aim of this work is to phytochemically characterize the extract of red dragon fruit (Hylocereus costaricensis) and evaluate its antioxidant, anti-hyperglycemic and anti-inflammatory activities. 165.8 ± 0.8 mg EAG/100 g of fresh fruit of total phenols and 110.1 ± 0.6 mg EC/100 g of fresh fruit of flavonoids were found in the extract obtained with water, which was the extraction reagent with the highest yield. Using the HPLC-DAD-MS/MS method, it was possible to identify phenolic compounds such as citric acid, succinic acid, ferulic acid, cyanidin-3-o-rutinoside, rutin, phyllocactin and betanin in the dragon fruit extract. The antioxidant activity of the dragon fruit extract was assessed by the DPPH method, which showed a free radical scavenging capacity of 33.4%; and by the in vitro method of intracellular reactive oxygen species production in HaCaT cells, where the 10 mg/mL dragon fruit extract showed a 95% reduction capacity of reactive oxygen species caused by oxidative stress by ultraviolet light. These results indicate that the extract has antioxidant potential. An animal model of hyperglycemic induction with glucose overload was used to evaluate the antihyperglycemic activity. Administration of the extract at a dose of 10 mg EAG/kg for 15 days, before glucose overload, showed anti-hyperglycemic activity. The animal model of acute local inflammation induced by carrageenan was used to assess anti-inflammatory activity. The administration of extracts at doses of 5 mg EAG/kg and 10 mg EAG/kg for 15 days proved to have anti-inflammatory activity, since the phenolic compounds in the extract were able to reduce the edema caused by carrageenan. It was possible to see greater efficacy in reducing edema with the more concentrated dose (10 mg EAG/kg) of the extract, which suggests that the anti-inflammatory effect is dose dependent. Therefore, our results suggest that the phenolic extract of dragon fruit may play an important role in protecting human health when incorporated into the diet, since it was able to show antioxidant, anti-hyperglycemic and anti-inflammatory properties.
Chronic non-communicable diseases are one of the main causes of premature death worldwide, such as diabetes, cardiovascular disease, and cancer. At the root of the development of these diseases are risk factors that can be controlled. One of them is diet. High-calorie foods, high in sugar and fat, especially saturated fat, favor the development of these diseases. On the other hand, there are foods that contain compounds with antioxidant and anti-inflammatory effects, capable of preventing these diseases, or at least slowing down their development. The search for these foods has been a concern recently. Dragon fruit, a fruit that is still little known to the European population, is beginning to be described as a source of compounds with functional properties that can prevent the development of certain diseases. Examples of these compounds include some vitamins and phenolic compounds with important physiological actions in the prevention of some chronic diseases. The aim of this work is to phytochemically characterize the extract of red dragon fruit (Hylocereus costaricensis) and evaluate its antioxidant, anti-hyperglycemic and anti-inflammatory activities. 165.8 ± 0.8 mg EAG/100 g of fresh fruit of total phenols and 110.1 ± 0.6 mg EC/100 g of fresh fruit of flavonoids were found in the extract obtained with water, which was the extraction reagent with the highest yield. Using the HPLC-DAD-MS/MS method, it was possible to identify phenolic compounds such as citric acid, succinic acid, ferulic acid, cyanidin-3-o-rutinoside, rutin, phyllocactin and betanin in the dragon fruit extract. The antioxidant activity of the dragon fruit extract was assessed by the DPPH method, which showed a free radical scavenging capacity of 33.4%; and by the in vitro method of intracellular reactive oxygen species production in HaCaT cells, where the 10 mg/mL dragon fruit extract showed a 95% reduction capacity of reactive oxygen species caused by oxidative stress by ultraviolet light. These results indicate that the extract has antioxidant potential. An animal model of hyperglycemic induction with glucose overload was used to evaluate the antihyperglycemic activity. Administration of the extract at a dose of 10 mg EAG/kg for 15 days, before glucose overload, showed anti-hyperglycemic activity. The animal model of acute local inflammation induced by carrageenan was used to assess anti-inflammatory activity. The administration of extracts at doses of 5 mg EAG/kg and 10 mg EAG/kg for 15 days proved to have anti-inflammatory activity, since the phenolic compounds in the extract were able to reduce the edema caused by carrageenan. It was possible to see greater efficacy in reducing edema with the more concentrated dose (10 mg EAG/kg) of the extract, which suggests that the anti-inflammatory effect is dose dependent. Therefore, our results suggest that the phenolic extract of dragon fruit may play an important role in protecting human health when incorporated into the diet, since it was able to show antioxidant, anti-hyperglycemic and anti-inflammatory properties.
Descrição
Tese de mestrado, Qualidade Alimentar e Saúde, 2023, Universidade de Lisboa, Faculdade de Farmácia.
Palavras-chave
Hylocereus costaricensis Atividade antioxidante Atividade antihiperglicémica Atividade anti-inflamatória Teses de mestrado - 2023