Vasorelaxant Effects of Coriandrum SativumL. Extract on Rat Isolated Aorta

Aim: Coriander(Coriandrum sativum L.) is an annual plant belonging to the family Umbelliferae, which distributed in Central and Western Europe, India, Bangladesh, Thailand, China, and other Asian regions. Besides being edible, coriander is an important traditional medicine in India and China, and is used to treat circulatory disorders, such as respiratory, urinary tract, and skin diseases. In this study, we investigated the vasorelaxant effects of extracts from coriander and further studied to clarify their action mechanisms. Method: The aerial part of coriander, which analyzed the rutin content as its quality evaluand using a chromatographic method (HPLC), was cut and extracted with ethyl acetate or hot water. The extracts were concentrated under the reduced pressure. Vasorelaxant effects of these extracts were assessed on rat isolated aorta. The aorta was placed in a well-oxygenated bath of modified Krebs-Henseleit solution and the mechanical tension was measured isometrically. Results: These extracts showed vasorelaxant effects on aorta precontracted with 3×10-7 M norepinephrine (NE). The ethyl acetate extract showed biphasic vasorelaxation (fast and slowly developing relaxations) on isolated rat aortic rings with endothelium. Fast relaxation disappeared in deendothelialized or pre-administration of 10-4 M L-NG-monomethylarginine. Furthermore, the hot water extract showed only slowly developing relaxations independent in endothelium. After treatment with the hot water extract, NE-induced phasic vasoconstriction was not inhibited. While the hot water extract inhibited vasoconstrictions induced by a high concentration (60 mM) of K+ and also showed inhibitory effect on NE-induced vasoconstriction in the presence of nicardipine. Conclusion: These results suggest that the vasorelaxant effect of ethyl acetate extract of coriander on NE-induced vasoconstriction may be attributed to Nitric Oxide (NO) releasing dependent on endothelium. And the hot water extract of coriander showed vasorelaxant activities attributed to blocking of Ca2+ influx via voltage-depended Ca2+ channels (VDCs) and receptor-operated Ca2+ channels (ROCs), but not competing for the adrenergic receptor. Keywords: Coriandrum sativum; quality evaluation; vasorelaxant effects; aorta; endothelium; Ca2+ channel