Exploration of antiplasmodial activity of Miconia theaezans leaf extracts and isolated compounds against Plasmodium falciparum

Malaria remains one of the most devastating infectious diseases globally, causing hundreds of thousands of deaths annually, particularly in tropical and subtropical regions. Despite advances in prevention and treatment, the growing resistance to conventional antimalarial drugs emphasizes the urgent need for novel therapeutic agents [ 1 ] [ 2 ]. This study investigates the antiplasmodial potential of Miconia theaezans (Melastomataceae) leaf extracts and isolated compounds and fractions. The antiplasmodial activity of various extracts, chromatographic fractions, and isolated compounds was evaluated in vitro against Plasmodium falciparum FCR-3, showing significant inhibition of parasite growth with IC 50 values below 100 μg/mL. Bioassay-guided fractionation led to the isolation of two compounds, whose structures were elucidated by NMR and MS analyses. One of the isolated compounds demonstrated notable antiplasmodial activity. Cytotoxicity was assessed in 3T3 fibroblasts, confirming minimal toxicity to mammalian cells. These findings support the antiplasmodial potential of M. theaezans , both in crude extracts and in specific isolated compounds [ 3 ]. The ongoing identification and profiling of secondary metabolites through LC-MS aim to further clarify the chemical basis of the observed bioactivity. This work contributes to the discovery of novel lead compounds for the development of future antimalarial therapies. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany