Elecampane (Inula helenium), also called Horse-heal or Marchalan (in Welsh), is a perennial composite plant common in many parts of Great Britain, and ranges throughout central and Southern Europe, and in Asia as far eastwards as the Himalayas. It is naturalized in North America. Botanical Description It is a rather rigid herb, the stem of which attains a height of from 90 cm to 150 cm; the leaves are large and toothed, the flowers are yellow. The MeOH extract of the roots of Inula helenium showed a high inhibitory activity for cell growth against MK-1, HeLa and B16F10 cell lines. Significant activity was found in the hexane-soluble fraction. From the hexane-soluble fraction, seven sesquiterpenes, namely, one germacrane (4beta,5alpha-epoxy-1(10),11(13)-germacradiene-8,12-olide), one elemane (igalane), and five eudesmanes (alantolactone, isoalantolactone, 11alpha,13-dihydroalantolactone, 11alpha,13-dihydro-isoalantolactone, 5-epoxyalantolactone) were isolated.