Caracterização química dos extratos de carqueja (Pterospartum tridentatum, Wilk) e de erva de S. Roberto (Geranium robertianum, L.) e avaliação da sua toxicidade usando modelos in vitro
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2014
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As plantas são utilizadas pelo homem desde tempos imemoriais no tratamento de patologias diversas. As plantas contêm na sua composição inúmeros compostos, como por exemplo os compostos resultantes do metabolismo secundário, que, das suas várias funções, são responsáveis por inibir outras moléculas como por exemplo as espécies reativas de oxigénio (ROS) presentes nos seres vivos. Devido à crescente procura de terapias alternativas, recorrendo ao uso de substâncias não sintéticas, à evolução da tecnologia e ao interesse por parte dos investigadores em caracterizar e estudar a aplicação das plantas na área medicinal, tem aumentado a investigação da atuação de compostos naturais provenientes das plantas.
Existem inúmeras plantas utilizadas tradicionalmente em Portugal para o tratamento de várias patologias, como por exemplo a carqueja (Pterospartum tridentatum, Wilk) e a erva de S. Roberto (Geranium robertianum, L.) espécies endémicas de Portugal. São utilizadas pelo seu efeito anti-inflamatório, anti-diabético, anti-cancerígeno, anti-asmático, anti-alérgico e diurético, para o tratamento de problemas do sistema digestivo, entre outros. Assim, com a sua extensa aplicação é importante e necessário o conhecimento da aplicação dos extratos no organismo, sendo essencial saber a sua forma e local de ação e se efetivamente existe fundamento científico para todas estas aplicações.
O objetivo deste trabalho foi obter uma breve caracterização química dos extratos aquosos e hidro-etanólicos de carqueja (Pterospartum tridentatum Wilk.) e erva de S. Roberto (Geranium robertianum L.), bem como estudar o efeito da aplicação destes extratos nas linhas celulares HepG2 e Caco-2 (ensaios in vitro) para avaliar a sua potencial citotoxicidade e pesquisar a presença de possíveis compostos bioativos moduladores de vias intracelulares (e.g. apoptose) que interfiram com a proliferação celular ou com processos reresponsáveis pelos atributos medicinais das plantas.
Os principais compostos fenólicos encontrados para a carqueja foram a floretina, a isoquercetina e a miricetina. Na erva de S. Roberto foram identificados como compostos fenólicos a luteolina, o ácido elágico, um derivado da apigenina e a geraniina.
Aplicaram-se todos os extratos (aquosos e hidro-etanólicos) e frações após SPE (aquosas e metanólicas) obtidas às duas linhas celulares nas concentrações de 50, 100, 200 e 500 μg/mL, e a viabilidade celular foi medida ao fim de 24, 48 e 72 h de exposição. Verificou-se que os extratos que apresentam maior capacidade para reduzir o crescimento celular foram, no caso da carqueja os extratos aquosos iniciais nas concentrações de 200 e 500 μg/mL. Os extratos que
apresentam maior capacidade para reduzir o crescimento celular na erva de S. Roberto foram os extratos hidro-etanólicos iniciais e a fração metanólica após SPE nas concentrações de 100, 200 e 500 μg/mL.
Podemos concluir que efetivamente os extratos levaram à diminuição do crescimento e da viabilidade das linhas celulares Caco-2 e HepG2 demonstrado que a sua atividade biológica é determinada pelo tipo e concentração dos seus compostos.
Plants were always used by the human population like a traditional form of treatment for innumerous diseases. Resulting from plant’s secondary metabolism, plants have in their composition various compounds with several properties, among them the capacity to inhibit other molecules like reactive oxygen species (ROS) present in the living organisms. Due to the increasing demand of therapies that use non-synthetic substances, to the evolution of the technology and to the interest from the scientists in characterizing and studying the application of plants in the medicinal area, it has been increasing the research of the potential bioactive role of natural compounds from the plants. There are countless plants traditionally used for the treatment of several pathologies, as prickled broom or “carqueja” (Pterospartum tridentatum, Wilk) and herb Robert (Geranium robertianum, L.), two endemic plants of Portugal. They are used due to their anti-inflammatory, anti-diabetic, anti-carcinogenic, anti-asthmatic, anti-allergic and diuretics properties, as well as for the treatment of digestive system ailments, between others medicinal properties. Thus, with its extensive application, it is important and necessary to acquire knowledge about the effects of plants extracts in the organism, being essential to understand the targets and the metabolic pathways involved in the mechanism of action and if their use brings profits to cell metabolism or is just empirical. The main goal of the proposed research is to perform a brief chemical characterization of Pterospartum tridentatum Wilk. and Geranium robertianum L. extracts, and evaluate the in vitro effect of the application of these extracts, using Caco-2 and HepG2 cell lines, in order to investigate its potential cytotoxicity or its potencial effects as modulator of important physiological pathways involved on the cell proliferation and viability mechanisms. The presence of potential bioactive compounds with the ability to modulate/induce apoptotic pathways will also be investigated. The main phenolic compound identified in P. tridentatum were floretin, isoquercetin and mirycetin. G. robertianum major phenolic compounds found were luteolin, ellagic acid, apigenine derivative and geraniin The extracts (aqueous and hydro-ethanolic) and fractions (aqueous and methanolic) were applied to both cell lines at concentrations of 50, 100, 200 and 500 μg/mL and cell viability was measured after 24, 48 and 72 h of exposures. The extracts that show higher capacity to reduce cell growth were, in P. tridentatum the initial water extract at 200 and 500 μg/mL concentration. G. robertianum extracts that showed higher capacity to reduce cell viability were initial hydroethanolic extracts and methanolic fraction before SPE, in 100, 200 and 500 μg/mL. In conclusion the extracts showed a reduce of cell viability and/or cell growth in both cell lines, Caco-2 and HepG2 and their activity are determined by the type and concentration of the present compounds.
Plants were always used by the human population like a traditional form of treatment for innumerous diseases. Resulting from plant’s secondary metabolism, plants have in their composition various compounds with several properties, among them the capacity to inhibit other molecules like reactive oxygen species (ROS) present in the living organisms. Due to the increasing demand of therapies that use non-synthetic substances, to the evolution of the technology and to the interest from the scientists in characterizing and studying the application of plants in the medicinal area, it has been increasing the research of the potential bioactive role of natural compounds from the plants. There are countless plants traditionally used for the treatment of several pathologies, as prickled broom or “carqueja” (Pterospartum tridentatum, Wilk) and herb Robert (Geranium robertianum, L.), two endemic plants of Portugal. They are used due to their anti-inflammatory, anti-diabetic, anti-carcinogenic, anti-asthmatic, anti-allergic and diuretics properties, as well as for the treatment of digestive system ailments, between others medicinal properties. Thus, with its extensive application, it is important and necessary to acquire knowledge about the effects of plants extracts in the organism, being essential to understand the targets and the metabolic pathways involved in the mechanism of action and if their use brings profits to cell metabolism or is just empirical. The main goal of the proposed research is to perform a brief chemical characterization of Pterospartum tridentatum Wilk. and Geranium robertianum L. extracts, and evaluate the in vitro effect of the application of these extracts, using Caco-2 and HepG2 cell lines, in order to investigate its potential cytotoxicity or its potencial effects as modulator of important physiological pathways involved on the cell proliferation and viability mechanisms. The presence of potential bioactive compounds with the ability to modulate/induce apoptotic pathways will also be investigated. The main phenolic compound identified in P. tridentatum were floretin, isoquercetin and mirycetin. G. robertianum major phenolic compounds found were luteolin, ellagic acid, apigenine derivative and geraniin The extracts (aqueous and hydro-ethanolic) and fractions (aqueous and methanolic) were applied to both cell lines at concentrations of 50, 100, 200 and 500 μg/mL and cell viability was measured after 24, 48 and 72 h of exposures. The extracts that show higher capacity to reduce cell growth were, in P. tridentatum the initial water extract at 200 and 500 μg/mL concentration. G. robertianum extracts that showed higher capacity to reduce cell viability were initial hydroethanolic extracts and methanolic fraction before SPE, in 100, 200 and 500 μg/mL. In conclusion the extracts showed a reduce of cell viability and/or cell growth in both cell lines, Caco-2 and HepG2 and their activity are determined by the type and concentration of the present compounds.
Descrição
Dissertação de Mestrado em Bioquímica
Palavras-chave
Planta medicinal , Antioxidante , HPLC , Carqueja (Pterospartum tridentatum Wilk.) , Erva de S. Roberto (Geranium robertianum L.) , Atividade anticancerígena