The International Institute for Science, Technology and Education (IISTE)
Abstract
The current study represents the first attempt to investigate the effect of the Euscaphic acid (EA) on Rats isolated thoracic aortic smooth muscle cells. Isolated aorta was used to test the anti-contraction effects and the possible mode of action(s) of the EA (1*10-7 M) and (3*10-7 M) isolated from Crataegus azarolus var. aronia L. Euscaphic acid showed high anti-contraction effects on norepinephrin (NE), (1*10-9-10-4 M) induced contraction in aortic smooth muscle cells in endothelium-intact, endothelium-denuded, and aortic rings pre-incubated with potassium (K+)-channels blocker (tetraethylammonium, TEA), prostaglandin I2 (PGI2) inhibitor (indomethacin) and cyclic guanosine monophosphate (cGMP) inhibitor ( methylene blue). On the other hand, other K+ channels subtype blockers glibenclamide (GLIB); barium chloride (BaCl2) and 4-aminopyridine (4-AP) demonstrated that adenosine triphosphate sensitive K+ (KATP), inwardly rectifying K+ (Kir) and voltage-dependent K+ (KV) channels played no role in anti-contraction induced by EA. Furthermore, the role of L-types calcium (Ca++) channels in EA anti-contractile effects on aortic smooth muscle cells was proved, by using the Ca++-channel blocker verapamil, as indicated by the production of a potent anti-contraction effect . The results of the current study indicate that the anti-contraction effects of EA may be due to the activation of calcium dependent, K+ (KCa) channels and blocking of L-type Ca++ channels. Thus, from these results it can be concluded that both K+ and Ca++ channels play an important role in anti-contraction effects of EA, which are mediated possibly through opening of KCa channels and blockade of voltage-dependent calcium channels, which may justify the use of medicinal plant C. azarolus in cardiovascular disease. Keywords: Crataegus azarolus var. aronia, Euscaphic acid, smooth muscle cells, K+-channels blockers, Ca++-channels blocker
