Spasmolytic Activity of Essential Oil of Artemisia thuscula Cav. from the Canary Islands

ABSTRACT The present in vitro work studied (against carbachol) the spasmolytic activity of the essential oil obtained from the flowers of two chemotypes of Artemisia thuscula, endemic plant in the Canary Islands. Both oils displayed dose-dependent and essentially noncompetitive spasmolytic action. The davanone chemotype (46%) found in the samples gathered from the island of Tenerife, was more potent, and its spasmolytic activity was attributable mainly to the davanone itself. The camphor chemotype (36%) found in the samples gathered from the island of Hierro was less active; its spasmolytic effect clearly is not due to camphor. The spasmolytic effect of this camphor chemotype is believed to be due in part to the β-thujone content; however, the majority of the activity is probably due to other substances present in the oil.