RESUMO
AbstractAphelandra scabra (Vahl) Sm., Acanthaceae, is a shrub widely used by some Mayan communities as carminative, antidote, and remedy for some infections. Bio-guided isolation of the methanol extract of leaves led us to the purification of the anti-giardial metabolites cirsimaritin and sorbifolin, along with the inactive metabolites cirsimarin, sorbifolin-6-O-β-glucopyranoside, and squalene. Cirsimaritin displayed high activity in the anti-giardial bioassay with an IC50 = 3.8 μM, being considered as outstanding when compared to previous reported metabolites, while sorbifolin showed a low activity with an IC50 = 75.6 μM. Additionally, both compounds proved not to be cytotoxic in an in vitro bioassay against HEK-293, a normal cell line. This is the first investigation on anti-giardial properties of A. scabra and its phytochemistry as well, thus the isolated compounds are considered as new for the plant genus and for the species.