Author(s): Haydelba D’Armas, Victoria Vásquez and Gabriel Ordaz

Abstract: Crude extracts from Helicteres guazumifolia aerial parts were obtained with petroleum ether and methanol, and their biological activities were evaluated. Preliminary phytochemical screening of extracts indicated the possible presence of alkaloids, saponins, sesquiterpenlactones, sterols, and terpenoids in several extracts tested. Almost all of them were lethal against brine shrimp Artemia salina, especially polar extracts of the fruit (LC₅₀ = 17.82 μg·mL^-1), which suggest the presence of possible potent pharmacological agents in this Helicteres specie. Additionally, these extracts showed a sight antimicrobial activity, inhibiting the growth of several bacteria (Micrococcus lutens, Enterobacter cloacae, Acinetobacter calcoaceticus, Bacillus subtilis) and fungus (Aspergillus oryzae, Curvularia lunata, Mucor sp.). The results obtained indicate that H. guazumifolia Kunth collected in Venezuela is a promising source of bioactive secondary metabolites with pharmacological activity.