Antifungal and antiparasitic activity of Wunderlichia azulensis (Asteraceae) roots

Abstract

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 μg.mL⁻¹/24 h). Fractions 5 and 7 inhibited yeast growth in proportions between 63.9–80.7% at 50 μg.mL⁻¹, and 70.3–96.7% at 100 μg.mL⁻¹. Fractions 5 and 7 (100 μg.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.

Keywords:

• Asteraceae
• anticandidal activity
• antiparasitic activity
• roots
• sesquiterpene lactones

Acknowledgements

We thank the Multiuser Center of the Laboratório de Biologia Celular e Tecidual for the infrastructure provided, and Beatriz F. Ribeiro for the technical work at the Laboratório de Biologia Celular e Tecidual of the Universidade Estadual do Norte Fluminense Darcy Ribeiro. We also thank Tatiane Pereira de Souza for identifying the species.

Disclosure statement

The authors report there are no competing interests to declare.

Additional information

Funding

This study was financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES - PNADB 1146/2012), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq − 474966/2012-7), and Fundação de Amparo à Pesquisa do Rio de Janeiro (FAPERJ - E-26/010.002647/2014).