Taylor Nelson, Weber State University
Botany
Arnica is a common form of complementary medicine used to treat bruises and sore muscles. Most arnica preparations are made as an oil or gel by soaking the flowers of Arnica montana (a member of the Asteraceae) in an oil, such as olive oil, to extract helenalin, the presumed active component. Helenalin, a sesquiterpene lactone, has been shown to inhibit transcription factor NF-?B, a factor which controls the expression of dozens of genes involved in inflammation responses (Rungeler et al. 1999). Due to arnica’s popularity, A. montana is becoming scarce in Europe (its native range) and is sometimes substituted commercially with A. chamissonis (Cassells et al. 1999). Therefore, this study focused on finding other sources of helenalin among the Asteraceae. A. chamissonis, A. cordifolia, A. latifolia, A. longifolia, A. mollis and Helianthella uniflora were collected from Alta, UT, and Helenium autumnale from Salt Lake City, UT, at elevations of approximately 10,500 feet and 4,200 feet, respectively. Sesquiterpenes were extracted from the flowers by dipping them in methylene chloride and separated by thin-layer chromatography. Helenalin and possible helenalin derivatives were identified by their reaction with vanillin and comparison to a pure helenalin standard. Flowers from all seven of the species contained helenalin, with Helenium autumnale containing the highest concentration and A. latifolia the lowest. Therefore, all of the species tested in this study have the potential to be used commercially to prepare arnica salves and thus allow the A. montana population to re-establish itself. An additional finding was that A. chamissonis grew the best under greenhouse conditions, which may explain its substitution in some commercial salves.