[Detection the vasodilator aspects of achillea fragrantissima ethanolic extract in comparison with vasodilator drugs]

ABSTRACT

The vasodilator effect of ethanolic extract of Achillea Fragrantissima [Asteraceae] was detected at several levels in isolated and phenylephrine- precontracted rabbit aortic rings. First, The role of potassium channels and beta[2] receptors was determined by using the selective blockers for each of them Charybdotoxine and Propranolol, respectively. Secondly, there was a set of experiments in which a Ca[+2] free Krebs solution was used and pheylephrine contracted the rings following by re-injection of Ca[+2] ions to the medium, this step was repeated in the presence of the extract. The vasodilator drugs Diltiazem and Prazocine were used as reference and for evaluation. This extract showed a profound relaxing effect on phenylephrine- precontracted aortic rings, which was partially related to potassium channels and beta[2] receptors. In experiments that used Ca[+2] free Krebs solution, the extract inhibited partially the first phase contraction [pheylephrine contraction] and the second phase contraction which is due for calcium entry via calcium channels, with more potent for the last one and this was similar to Diltiazem. The vasodilator effect of ethanolic extract of Achillea Fragrantissima is largely related to calcium channels and this emphasis the need for isolation of related compound[s].