Vasodilatory effects and underlying mechanisms of the ethyl acetate extracts from Gastrodia elata Blume

The objective of this study was to assess the ethyl acetate extracts of Gastrodia elata Blume (GEB) on vascular tone and the mechanisms involved. GEB was extracted with 95% EtOH followed by a further extraction with ethyl acetate. The effects of GEB and its ingredients on the isometric tensions of the aortic rings from rats were measured. The ethyl acetate extract of GEB induced a vasodilatatory effect on rat aorta which was partially dependent on endothelium. Four chemical compounds isolated from GEB were identified as 3, 4-dihydroxybenzaldehyde (DB), 4-hydroxy benzaldehyde (HB), 4-methoxybenzyl alcohol (MA) and 4, 4â -dihydroxydiphenyl methane (DM), respectively. All of these compounds induced vasodilatations which were dependent on the endothelium to different degrees. After pretreated with NĎ -nitro-L-arginine methyl ester, indomethacin or methylene blue, the vasodilatations induced by DB, HB and MA were significantly decreased. In addition, the contractions of the rat aortic rings due to Ca2+ influx and intracellular Ca2+ release were also inhibited by DM. Furthermore, the administration of DB significantly enhanced the productions of nitric oxide (NO) and the activities of the endothelial NO synthase in aorta and in endothelial cells. Thus, GEB may play an important role in the amelioration of hypertension by modulating vascular tones.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author