Effects of extract, fractions and 2,3-dihydromyricetin-3-O-α-L-rhamnoside from Pradosia huberi (Ducke) Ducke on rat isolated mesenteric arteries

Revista Brasileira de Farmacognosia

Queiroz, Thyago M.¹  Silva, Marcelo S.¹  Medeiros, Alessandra A. N.¹  Medeiros, Fernando A.¹  Medeiros, Isac A.¹  Tavares, Josean F.¹  Instituto de Pesquisas Científicas e Tecnológicas do Amapá, Macapá, Brasil¹  Universidade Federal da Paraíba, João Pessoa, Brazil¹ 

关键词: Pradosia huberi;    mesenteric artery;    vasodilatation;    dependent-endothelium;    2;    3-dihydromyricetin 3-O-α-L-rhamnoside;    Amazon Rainforest.;   

DOI  :  10.1590/S0102-695X2010000400013

来源: Sociedade Brasileira de Farmacognosia

【 摘 要 】

Pradosia huberi (Ducke) Ducke (Sapotaceae), an Amazonian species, is popularly known as "casca-doce" and used in the folk medicine for the treatment of gastritis. The ethanol extract of the bark contains mainly polyphenolic compounds, which are known to show a large number of activities, including cardioprotective and vasorelaxant effects. The aim of this study was to evaluate the pharmacological properties induced by P. huberi ethanol extract (PHEE) and fractions and 2-3-dihydromyricetin-3-O-α-L-rhamnoside derived from this extract, in isolated rat mesenteric arteries. PHEE was separated and the following fractions were obtained: CHCl3, CHCl3:AcOEt (1:1), AcOEt, AcOEt:MeOH (1:1) and MeOH. We isolated 2-3-dihydromyricetin-3-O-α-L-rhamnoside from the MeOH fraction, which was identified by 1H and 13C NMR spectra and compared with data in the literature. PHEE (1-100 µg/mL) induced concentration-dependent relaxations of 10 µM phenylephrine-induced tone (EC50=17,1±2,9 µg/mL; Emax=87.4±2.9 %, n=8). The MeOH fraction also relaxed mesenteric rings (EC50=31±2.0 µg/mL; Emax=54±12.5%, n=6) but less effectively when compared to PHEE. Both effects were completely abolished after removal of the vascular endothelium. The AcOEt:MeOH (1:1) fraction and the isolated flavonoid were ineffective in eliciting vasorelaxation. The study demonstrates that PHEE and MeOH fraction of Pradosia huberi possess a vasorelaxant effect, which may be completely dependent upon endothelium. The isolated flavonoid is not responsible for this vasorelaxant effect.

【 授权许可】

Unknown