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Authors
Abstract(s)
As plantas são cada vez mais procuradas como alternativa aos fármacos
convencionais. O espinheiro (Crataegus monogyna Jacq.), tem sido bastante estudado
pelas suas características etnofarmacológicas documentadas desde há muito tempo.
Havendo já resultados promissores sobre o efeito antioxidante de extratos de diferentes
partes de C. monogyna, era credível que a sua incorporação em formulações
farmacêuticas poderia permitir o desenvolvimento de produtos com grande potencial.
A pele, sendo uma barreira entre o meio exterior e interior, está continuamente
exposta ao stresse oxidativo. Para reparar eventuais danos, são necessários
antioxidantes, que podem ser obtidos de forma endógena ou exógena. As formulações
semi-sólidas (géis) de aplicação tópica constituem uma forma eficaz de fornecer
compostos antioxidantes à pele. Neste trabalho, foram preparados hidrogéis livres de
parabenos, usando carbopol 940 como agente gelificante. Os extratos obtidos a partir de
diferentes partes de C. monogyna, incorporados nestes hidrogéis, bem como as
formulações finais, foram avaliados quanto à sua atividade antioxidante. As partes de C.
monogyna com maior bioatividade foram as flores e os frutos imaturos, enquanto os
extratos etanólicos se apresentaram mais bioativos que os aquosos. Os hidrogéis
apresentaram uma consistência adequada, uma textura não gordurosa e uma cor
agradável; a sua atividade antioxidante foi quase totalmente mantida em relação aos
extratos a partir dos quais foram preparados. Tendo sido testados na pele, os hidrogéis
foram prontamente absorvidos e não apresentaram alterações significativas de pH
durante 90 dias.
Foi também avaliada a capacidade de inibição do crescimento de células tumorais
em quatro linhas celulares humanas: MCF-7 (adenocarcinoma de mama), NCI-H460
(adenocarcinoma de pulmão), Hela (carcinoma do colo do útero) e HepG2 (carcinoma
hepatocelular). Os extratos de botões florais apresentaram a maior atividade
antiproliferativa, como indicado pelos menores valores de GI50 obtidos para todas as
linhas celulares. Para a avaliação da toxicidade dos extratos em células não tumorais,
utilizou-se uma cultura primária (PLP2) obtida a partir de fígado de porco. Estes
extratos foram caracterizados por HPLC-DAD-ESI/MS, verificando-se que osflavonóides, especialmente flavonóis e flavonas (maior quantidade nos botões florais) e
as procianidinas (maior quantidade nos frutos imaturos) foram as classes maioritárias.
Os ácidos fenólicos também foram detetados em quantidades significativas,
principalmente nos extratos florais. Os frutos maduros apresentaram uma maior
quantidade de antocianinas.
Em suma, o material vegetal estudado, obtido a partir do espinheiro, revelou bons
índices de bioatividade, quer antioxidante, quer antiproliferativa, e os seus extratos
demonstraram ser adequados para incorporar em géis hidrossolúveis de aplicação
dérmica. Estes géis apresentaram características físicas e bioativas que comprovam a
sua qualidade e potencial para aplicações dermatológicas
Plants have been increasingly sought as an alternative to conventional drugs. Hawthorn (Crataegus monogyna Jacq.), has been extensively studied for its previously documented ethnopharmacological benefits. The promising results on the antioxidant effect of extracts of different parts of C. monogyna, raised the possibility of its incorporation in pharmaceutical formulations to develop products with great potential. As a protective barrier between the exterior and interior milieu, the skin is continuously exposed to oxidative stress. To repair any damage, endogenous or exogenous antioxidants are needed. Semisolid formulations (gels) are topically applied to effectively provide antioxidants to the skin. In this work, hydrogels were prepared without parabens, using carbopol 940 as jellifying agent. The extracts incorporated into these hydrogels, as well as the final formulations, were evaluated for their antioxidant activity. The parts of C. monogyna with higher bioactivity were flowers and immature fruits, while ethanol extracts showed to be more bioactive than the aqueous. The hydrogels had a suitable consistency, non-greasy texture and a pleasing color. Their antioxidant activity was almost completely maintained in comparison to the extracts from which they were prepared. Having been tested on the skin, the hydrogels were readily absorbed and showed no significant changes in pH during 90 days. The ability to inhibit the growth of tumor cells was also assessed in four human cell lines: MCF-7 (breast adenocarcinoma), NCI-H460 (lung adenocarcinoma), Hela (cervical carcinoma) and HepG2 (hepatocellular carcinoma). Buds extracts gave the highest antiproliferative activity, as indicated by the lower GI50 values obtained for all cell lines. To evaluate the toxicity of the extracts in non-tumor cells, a primary culture (PLP2) was obtained from pig liver. These extracts were characterized by HPLC-DADESI/ MS, being verified that flavonoids, especially flavonols and flavones (higher in flower buds) and procyanidins (higher in immature fruits) were the major classes. Phenolic acids were also detected in significant amounts, especially in floral extracts. Ripe fruits had the highest anthocyanins amount. Briefly, the botanical parts of hawthorn showed good bioactivity (antioxidant and antiproliferative) and their extracts have shown to be appropriate to incorporate in water-soluble gels for dermal application. These gels showed physical and bioactive characteristics that prove their quality and potential for dermatological applications.
Plants have been increasingly sought as an alternative to conventional drugs. Hawthorn (Crataegus monogyna Jacq.), has been extensively studied for its previously documented ethnopharmacological benefits. The promising results on the antioxidant effect of extracts of different parts of C. monogyna, raised the possibility of its incorporation in pharmaceutical formulations to develop products with great potential. As a protective barrier between the exterior and interior milieu, the skin is continuously exposed to oxidative stress. To repair any damage, endogenous or exogenous antioxidants are needed. Semisolid formulations (gels) are topically applied to effectively provide antioxidants to the skin. In this work, hydrogels were prepared without parabens, using carbopol 940 as jellifying agent. The extracts incorporated into these hydrogels, as well as the final formulations, were evaluated for their antioxidant activity. The parts of C. monogyna with higher bioactivity were flowers and immature fruits, while ethanol extracts showed to be more bioactive than the aqueous. The hydrogels had a suitable consistency, non-greasy texture and a pleasing color. Their antioxidant activity was almost completely maintained in comparison to the extracts from which they were prepared. Having been tested on the skin, the hydrogels were readily absorbed and showed no significant changes in pH during 90 days. The ability to inhibit the growth of tumor cells was also assessed in four human cell lines: MCF-7 (breast adenocarcinoma), NCI-H460 (lung adenocarcinoma), Hela (cervical carcinoma) and HepG2 (hepatocellular carcinoma). Buds extracts gave the highest antiproliferative activity, as indicated by the lower GI50 values obtained for all cell lines. To evaluate the toxicity of the extracts in non-tumor cells, a primary culture (PLP2) was obtained from pig liver. These extracts were characterized by HPLC-DADESI/ MS, being verified that flavonoids, especially flavonols and flavones (higher in flower buds) and procyanidins (higher in immature fruits) were the major classes. Phenolic acids were also detected in significant amounts, especially in floral extracts. Ripe fruits had the highest anthocyanins amount. Briefly, the botanical parts of hawthorn showed good bioactivity (antioxidant and antiproliferative) and their extracts have shown to be appropriate to incorporate in water-soluble gels for dermal application. These gels showed physical and bioactive characteristics that prove their quality and potential for dermatological applications.
Description
Mestrado em cooperação com a Universidade de Salamanca