Antifungal and antiparasitic activity of Wunderlichia azulensis (Asteraceae) roots

The aim of this work was to evaluate the antifungal and antiparasitic activity of roots of Wunderlichia azulensis (Asteraceae). A CH2Cl2 partition of W. azulensis was tested against Candida tropicalis, C. buinensis and Trypanosoma cruzi parasites. A chemical study of the CH2Cl2 partition resulted in the isolation and identification of dehydrobrachylaenolide (1), lasiodiplodin (2), a taraxerane-type triterpene (3) and a mixture of sitosterol and stigmasterol (4-5). Of the 13 fractions tested, fractions 5 and 7 were the most bioactive ones. No live epimastigotes were observed even after the shortest time of exposure to fraction 7 (25 mu g.mL(-1)/24 h). Fractions 5 and 7 inhibited yeast growth in proportions between 63.9-80.7% at 50 mu g.mL(-1), and 70.3-96.7% at 100 mu g.mL(-1). Fractions 5 and 7 (100 mu g.mL(-1)) induced loss of viability of C. buinensis by 97.61 and 92.63%, respectively, whereas C. tropicalis was less susceptible. The SYTOX Green marker used on Candida yeasts suggested membrane permeabilization and consequently plasma membrane damage. We concluded that W. azulensis offers new sources of biologically-active components. However, complementary studies on other variables, such as synergy, toxicology, and mechanism of action, must be carried out.