Chemical composition and cruzain inhibitory activity of croton draco bark essential oil from monteverde, costa rica

Abstract

American trypanosomiasis, Chagas disease, is a great cause of human morbidity and mortality in the Neotropics. Although there is currently no effective treatment for this parasitic disease, a number of potential biochemical targets have been identified, including the cysteine protease cruzain. Croton draco Cham. & Schldl. (Euphorbiaceae), commonly known as sangre de drago, is used in traditional medicine for a number of maladies. In this study, Croton draco bark essential oil has been shown to inhibit the activity of cruzain. The bark oil has been analyzed by GC-MS and the major components found to be β-caryophyllene (31.9%), caryophyllene oxide (22.0%), 1,8-cineoIe (6.2%), and α-humulene (5.6%). The major components have been tested for cruzain inhibitory activity, but show minimal activity, so it is not clear if the activity of Croton draco bark oil is due to a synergistic effect of the essential oil components or due to very active minor components. Croton draco bark oil has also been tested for cytotoxic activity against a panel of human tumor cell lines, but shows little activity.