Identificação de agonistas e antagonistas de receptores nucleares em extratos de plantas medicinais : morus nigra l., plectranthus ornatus codd., ipomoea cairica (L) sweet e pouteria torta (mart.) radlk

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The use of plants for treatment and prevention of diseases is one the oldest medicinal practices. However, for several of these plants, few or none scientific evidence of their pharmacological properties are known. Natural products, including plant derivatives, have contributed to the development of new drugs. The aim of this study is evaluate four species widely used in Brazilian folk medicine, Morus nigra, Pouteria torta, Plectranthus ornatus, and Ipomoea cairica, in relation to their activities on estrogen (ERa and ERb) and glucocorticoid (GR) receptors. In the experimental conditions the ethanol extract of Morus nigra showed to be toxic for the U937 cells, the aqueous and hexane extracts did not present either an agonist or an antagonist action on ERa and ERb. The hexane extract of Pouteria torta presented non-competitive antagonist activity on ERb and no action on ERa. Ipomoea cairica hexane extract showed an antagonist effect on ERa and no action on ERβ. The compounds isolated from Ipomoea cairica, arctigenin glucoside, trachelogenin glucoside, 3,5-di-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid activated the transcription of ERa. This activation was lower than the activation obtained with estradiol. The trachelogenin glucoside and the 4,5-di-O-caffeoylquinic acid, in presence of estradiol, enhanced the ERb transcriptional activity. The hexane extract of Plectranthus ornatus increased the GR transcriptional activity as well as dexametasone. When were togheter, the hexane extract of Plectranthus ornatus and dexametasone, the GR transcriptional activity was enhanced. Diterpenes 11R*-acetoxykolavenic acid, 1a,6b,7b-triacetoxy-8,13R*-epoxy-14-labden-11-one, 1a,6b,7b-triacetoxy-9-hydroxy-8,13R*-epoxy-14-labden-11-one, isolated from the hexane extract of P. ornatus did not showed effects on the GR receptor. The use of plants for treatment and prevention of diseases is one the oldest medicinal practices. However, for several of these plants, few or none scientific evidence of their pharmacological properties are known. Natural products, including plant derivatives, have contributed to the development of new drugs. The aim of this study is evaluate four species widely used in Brazilian folk medicine, Morus nigra, Pouteria torta, Plectranthus ornatus, and Ipomoea cairica, in relation to their activities on estrogen (ERa and ERb) and glucocorticoid (GR) receptors. In the experimental conditions the ethanol extract of Morus nigra showed to be toxic for the U937 cells, the aqueous and hexane extracts did not present either an agonist or an antagonist action on ERa and ERb. The hexane extract of Pouteria torta presented non-competitive antagonist activity on ERb and no action on ERa. Ipomoea cairica hexane extract showed an antagonist effect on ERa and no action on ERβ. The compounds isolated from Ipomoea cairica, arctigenin glucoside, trachelogenin glucoside, 3,5-di-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid activated the transcription of ERa. This activation was lower than the activation obtained with estradiol. The trachelogenin glucoside and the 4,5-di-O-caffeoylquinic acid, in presence of estradiol, enhanced the ERb transcriptional activity. The hexane extract of Plectranthus ornatus increased the GR transcriptional activity as well as dexametasone. When were togheter, the hexane extract of Plectranthus ornatus and dexametasone, the GR transcriptional activity was enhanced. Diterpenes 11R*-acetoxykolavenic acid, 1a,6b,7b-triacetoxy-8,13R*-epoxy-14-labden-11-one, 1a,6b,7b-triacetoxy-9-hydroxy-8,13R*-epoxy-14-labden-11-one, isolated from the hexane extract of P. ornatus did not showed effects on the GR receptor.

ASSUNTO(S)

plectranthus ornatus fármacos ciencias da saude morus nigra(l) plantas medicinais

ACESSO AO ARTIGO

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