Stephan Maman and Holden Wagstaff, Southern Utah University
Life Sciences
Most plant species produce chemical compounds called secondary metabolites that enhance fitness in a variety of ways. Many of these compounds are also physiologically active in vertebrates and have widespread medicinal uses. The most ubiquitous secondary metabolites are the terpenoids, many of which cause vasodilation of the aorta and mesenteric arteries. In this study, we examined the vasoactive effects of the essential oil of Umbellularia californica, which contains the terpenoid umbellulone. Oil obtained via steam distillation using aerial portions of U. californica was applied directly to cutaneous arterioles of frogs. Arteriole diameter was monitored both before and after oil application by video microscopy. Within seconds of application, the oil caused significant vasoconstriction that persisted until the oil was washed off. Our control, medical grade sesame oil, caused no observable effects when applied using the same protocols. These results are opposite to the vasodilatory effects of terpenoids on aortic rings and mesenteric arteries. This suggests that the vasoactive effects of umbellulone are different from other terpenoids, that the vasoactive effects of terpenoids differ depending on blood vessel type, or that application of the complete essential oil affects vasculature differently than application of the isolated terpenoid.