EFEITO DE EXTRATOS VEGETAIS SELECIONADOS SOBRE A MUSCULATURA LISA DO TRATO GASTRINTESTINAL / EFFECT OF SOME EXTRACTS ON SMOOTH MUSCLE OF GASTRINTESTINAL TRACT

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The current study evaluated the possible antispasmodic activity of methanolic extracts, fractions and an active component from Brazilian medicinal plants on isolated guinea-pig ileum and rat duodenum preparations. Guinea-pigs of both sexes (300-350 g) and Male Wistar rats (250-300g) were sacrificed and the ileum and the duodenum muscle strips, respectively, were set up for recording the isotonic contractions in 5mL jacketed organ baths containing Tyrode solution at 37C, continuously bubbled with air under 1g of load. After an initial equilibration period of about 30-45 minutes, cumulative concentration-effect curves for acetylcholine (1 nM to 100 μM) in the absence or presence of methanolic extract of Rubus imperialis, Maytenus robusta, Epidendrum mosenii, Ipomoea pes-caprae, Calophyllum brasiliense and C. scolymus (0.102.0 mg/ml), of hexane, ethyl acetate, dichloromethane and butanolic fractions (0.10-2.0 mg/mL), obtained from the crude extract of C. scolymus leaves and cynaropicrin (0.01-0.2 mg/mL), a sesquiterpene isolated from dichloromethane fraction. Of the six medicinal plants evaluated, only C. brasiliense and C. scolymus exhibited significant inhibitory activity for the contractile response elicited by acetylcholine in a noncompetitive and concentration-dependent manner. The C. scolymus was studied in more detail because the promising results. Thus, the dichloromethane fraction showed the same oncompetitive and concentration-dependent manner antagonism obtained with the crude methanolic extract. This same antagonism was shown by cynaropicrin, with IC50 values of 65 ug/mL. These results confirm and justify the popular use of this plant for the treatment of gastrointestinal disorders, and that cynaropicrin is the main active principle of C. scolymus. However, additional studies are required to elucidate the mechanism of action.

ASSUNTO(S)

acetylcholine íleo isolado de cobaia acetilcolina guinea-pig ileum plantas medicinais medicinal plants farmacia farmacologia

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