تاثير خلاصتي نبات الاخيلية Achillea fragrantissima الايثانولية والمائية في التقلص الحاصل في الحلقات الابهرية المعزولة

Background & Objective: to investigate the relaxing effect of ethanolic and aqueous extracts of Achillea fragrantissima in rabbit aortic rings by investigation their effect on calcium movement through smooth muscle in which intracellular calcium concentrations increase during the phase of contraction. Material& methods: firstly: to elucidate the role of α1 adrenoceptors, a phenylephrine (PE) concentrationresponse curve was constructed in isolated rabbit aortic rings. Afterwards, the curve was repeated in presence of gradual- increased concentration of plant extract. The study was performed after checking the validation of this protocol. Secondly, contraction of rabbit aortic rings were done by high K+ Krebs solution (35 mM), then the extract was added cumulatively. there was a comparison with standard vasodilators: Prazocin, Nitroglycerine and Diltiazem as references. Results: The data showed an inhibition of this curve by the extracts with maximum effect for ethanolic one and the inhibition was for the maximum effect (Emax) to P.E. Indeed, the extracts have also shown a relaxing effect on aortic rings precontracted by high concentration of K+ ions. Conclusion: these data imply that the relaxing effect of the extracts includes an inhibition for calcium – induced contraction. The study should further continued to examine a possible effect of extract on calcium storage inside the cell.