Open AccessVasorelaxant and hypotensive effects of the extract and the isolated flavonoid rutin obtained from Polygala paniculata L.
Author(s) -
da Rocha Lapa Fernanda,
Soares Kelly Cristina,
Rattmann Yanna Dantas,
Crestani Sandra,
Missau Fabiana Cristina,
Pizzolatti Moacir Geraldo,
Marques Maria Consuelo Andrade,
Rieck Lia,
Santos Adair Roberto Soares
Publication year - 2011
Publication title -
journal of pharmacy and pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 118
eISSN - 2042-7158
pISSN - 0022-3573
DOI - 10.1111/j.2042-7158.2010.01240.x
Subject(s) - pharmacology , rutin , chemistry , apamin , antagonist , nitric oxide , potassium channel , nitric oxide synthase , atropine , histamine , receptor , biochemistry , anesthesia , endocrinology , medicine , antioxidant , organic chemistry
Objectives This study aimed to investigate the in‐vitro and in‐vivo cardiovascular effects of the crude hydroalcoholic extract from Polygala paniculata (HEPP) in rats. Methods The procedures were performed on aortic rings and on normotensive anaesthetized rats. Key findings When tested in endothelium‐intact aorta rings, HEPP (30–1000 µg/ml) produced a significant non‐concentration‐dependent relaxing effect (∼40%), which was completely prevented by incubation with L‐NAME (nitric oxide synthase inhibitor), ODQ (soluble guanylate cyclase inhibitor) and partially inhibited by tetraethylammonium (TEA; a non‐selective potassium channel blocker) and charybdotoxin (a large‐ and intermediate‐conductance calcium‐activated potassium channel blocker). In contrast, atropine (a muscarinic receptor antagonist) or pyrilamine(a histamine H 1 receptor antagonist) had no effect. Furthermore, oral administration of HEPP (30–300 mg/kg) in anaesthetized rats caused a dose‐dependent and sustained hypotensive action. This effect was unchanged by atropine or TEA, but was strongly reduced in rats continuously infused with L‐NAME or methylene blue. Moreover, rutin (1–3 mg/kg) administered by an intravenous route also caused a dose‐dependent hypotensive effect in rats. Conclusions Our results demonstrated that the extract obtained from P. paniculata induces potent hypotensive and vasorelaxant effects that are dependent on the nitric oxide/guanylate cyclase pathway. These effects could be related, at least in part, to the rutin contents in this extract.