RESUMO
Ageratina havanensis (Kunth) R. M. King & H. Robinson is a species of flowering shrub in the family Asteraceae, native to the Caribbean and Texas. The aim of this work was to compare the quantitative chemical composition of extracts obtained from Ageratina havanensis in its flowering and vegetative stages with the antioxidant potential and to determine the effects on P-glycoprotein (P-gp) function. The quantitative chemical composition of the extracts was determined quantifying their major flavonoids by UPLC-ESI-MS/MS and by PCA analysis. The effects of the extracts on P-gp activity was evaluated by Rhodamine 123 assay; antioxidant properties were determined by DPPH, FRAP and inhibition of lipid peroxidation methods. The obtained results show that major flavonoids were present in higher concentrations in vegetative stage than flowering stage. In particular, the extracts obtained in the flowering season showed a significantly higher ability to sequester free radicals compared to those of the vegetative season, meanwhile, the extracts obtained during the vegetative stage showed a significant inhibitory effect against brain lipid peroxidation and a strong reductive capacity. This study also showed the inhibitory effects of all ethanolic extracts on P-gp function in 4T1 cell line; these effects were unrelated to the phenological stage. This work shows, therefore, the first evidence on: the inhibition of P-gp function, the antioxidant effects and the content of major flavonoids of Ageratina havanensis. According to the obtained results, the species Ageratina havanensis (Kunth) R. M. King & H. Robinson could be a source of new potential inhibitors of drug efflux mediated by P-gp. A special focus on all these aspects must be taking into account for future studies.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Ageratina/química , Antioxidantes/química , Antioxidantes/farmacologia , Ativação do Canal Iônico/efeitos dos fármacos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Estrutura Molecular , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em TandemRESUMO
Medium and high polarity extracts from Maytenus species are known to contain polyphenolic compounds such as proanthocyanidins. The high polarity and structural complexity of these compounds make very difficult their isolation even by modern chromatographic techniques. Maytenus cajalbanica (Borhidi & O. Muñiz) Borhidi & O. Muñiz is endemic from Cuba. So far, there are reports neither of phytochemical work nor of biological evaluation of extracts from this subspecies. The goal of this work is to determine the polyphenolic profile and the antioxidant capacity of the ethanolic extract from the barks of Maytenus cajalbanica. FIA/ESI/IT/MSn analysis allowed the identification of 5 flavan-3-ol monomers, 33 proanthocyanidins, 2 free flavonoids and their respective glycosides as major compounds of the ethanolic extract, which showed a strong radical scavenging capacity and a significant ferric reduction power. FIA/ESI/IT/MSn technique led the rapid, effective and sensitive determination of the polyphenolic profile of Maytenus cajalbanica without previous separation.
Assuntos
Antioxidantes/farmacologia , Maytenus/química , Extratos Vegetais/farmacologia , Polifenóis/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Antioxidantes/química , Compostos de Bifenilo/química , Etanol/química , Flavonoides/análise , Glicosídeos/análise , Picratos/química , Casca de Planta/química , Extratos Vegetais/química , Polifenóis/química , Proantocianidinas/análiseRESUMO
The antiviral activity of extracts obtained from Ageratina havanensis (Kunth) R.M.King & H.Rob., Asteraceae, against rabbit vesivirus (RaV) (Caliciviridae) and human herpes simplex viruses type 1 and 2 (HSV-1, HSV-2) (Herpesviridae) were analyzed, and the main metabolites from the most active extract were isolated and characterized. The antiviral properties were investigated by measuring the inhibition of viral-induced cytopathic effect in Vero cells. The strongest inhibitory effects were found for ethyl acetate extract from leaves (SI=5 for RaV and SI=5.4 for HSV-1). The crude ethyl acetate extract was further fractionated by chromatographic methods and the structures of isolated compounds were established through comprehensive spectroscopic analyses, including IR, 2D NMR and MS. Four flavonoids were identified: 5,4'-dihydroxy-7-methoxyflavanone (sakuranetin), 3,5,4'-trihydroxy-7-methoxyflavanone (7-methoxyaromadendrin), 4'-O-β-D-glucosyl-5,3'-dihydroxy-7-methoxyflavanone (4'-O-β-D-glucosyl-7-methoxy-eriodictyol) and 4'-O-β-D-glucosyl-5-hydroxy-7-methoxyflavanone (4'-O-β-D-glucosylsakuranetin). This is the first report on antiviral activity for Ageratina havanensis.