Antiplasmodial Activity and Interactions of Persea americana Seed Flavonoids Against Plasmepsin II

Malaria caused by Plasmodium falciparum remains a major global health burden, and the increasing resistance to conventional antimalarial drugs urgently demands the discovery of novel bioactive compounds from natural sources. This study aimed to evaluate the antiplasmodial potential of methanol extract from Persea americana seeds and to identify its active phytochemical constituents through an integrated experimental and computational approach. The research design combined phytochemical profiling, in vitro antiplasmodial bioassay, and molecular docking simulation, contributing a mechanistic correlation between phytochemical composition and target-specific inhibitory activity-an aspect that remains insufficiently explored for this plant species. Phytochemical characterization was performed using high-performance liquid chromatography (HPLC) and gas chromatography–mass spectrometry (GC–MS). The in vitro antiplasmodial activity was evaluated against the P. falciparum strain 3D7 using a four-parameter logistic model, and molecular docking was performed against Plasmepsin II (PDB ID: 1LF3) using AutoDock Vina. HPLC analysis revealed the presence of seven flavonoids, of which rutin was the major compound (84.15%), followed by epicatechin (10.59%). GC–MS analysis detected volatile constituents, including avocadene acetate, avocadenofuran, linoleic acid, and palmitic acid. The extract showed high antiplasmodial activity with an IC₅₀ of 3.41 µg/mL against P. falciparum 3D7, which was within the WHO threshold for highly active plant extracts. Molecular docking revealed that kaempferol exhibited the strongest binding affinity toward Plasmepsin II (−8.10 kcal/mol), closely approaching chloroquine (−8.44 kcal/mol), and directly engaged the catalytic residue ASP214. These results demonstrate that P. americana seeds are a promising source of antiplasmodial compounds, and that structural compatibility with the target enzyme is a stronger determinant of binding affinity than compound abundance, positioning kaempferol as a lead candidate for further enzymatic and in vivo investigation.