Trypanocidal Activity of Smallanthus sonchifolius : Identification of Active Sesquiterpene Lactones by Bioassay-Guided Fractionation

• Published in: Evidence-based complementary and alternative medicine Vol. 2013; no. 2013; pp. 1 - 8
• Main Authors: Frank, Fernanda M., Ulloa, J., Cazorla, S. I., Maravilla, G., Malchiodi, Emilio, Grau, A., Martino, Virginia S., Catalán, César A. N., Muschietti, Liliana V.
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Hindawi Puplishing Corporation 01.01.2013; Hindawi Publishing Corporation; Hindawi Limited
• Subjects: Antimicrobial agents; Bioactive compounds; Bioassays; Biological activity; Chagas' disease; Chemical compounds; Chemistry; Chromatography; Chronic illnesses; Cytotoxicity; Disease; Fractionation; Herbal medicine; Lactones; Natural products; NMR; Nuclear magnetic resonance; Parasites; Plants; Protozoa; Replication; Sesquiterpene lactones; Smallanthus; Smallanthus sonchifolius; Staphylococcus infections; Tropical diseases; Trypanosoma cruzi; Trypomastigotes; Vector-borne diseases; Vero cells; Argentina
• ISSN: 1741-427X; 1741-4288
• DOI: 10.1155/2013/627898

In order to find novel plant-derived biologically active compounds against Trypanosoma cruzi, we isolated, from the organic extract of Smallanthus sonchifolius, the sesquiterpene lactones enhydrin (1), uvedalin (2), and polymatin B (3) by bioassay-guided fractionation technique. These compounds showed a significant trypanocidal activity against the epimastigote forms of the parasite with IC50 values of 0.84 μM (1), 1.09 μM (2), and 4.90 μM (3). After a 24 h treatment with 10 μg/mL of enhydrin or uvedalin, parasites were not able to recover their replication rate. Compounds 1 and 2 showed IC50 values of 33.4 μM and 25.0 μM against T. cruzi trypomastigotes, while polymatin B was not active. When the three compounds were tested against the intracellular forms of T. cruzi, they were able to inhibit the amastigote replication with IC50 of 5.17 μM, 3.34 μM, and 9.02 μM for 1, 2, and 3, respectively. The cytotoxicity of the compounds was evaluated in Vero cells obtaining CC50 values of 46.5 μM (1), 46.8 μM (2), and 147.3 μM (3) and the selectivity index calculated. According to these results, enhydrin and uvedalin might have potentials as agents against Chagas disease and could serve as lead molecules to develop new drugs.