Phytochemical composition and antimicrobial activity of ethanol and ethyl acetate extracts of Nauclea latifolia from Sierra Leone

Abstract

Nauclea latifolia (Pincushion tree) is a widely used medicinal plant across tropical Africa and Asia, traditionally employed to manage ailments such as jaundice, fever, dysentery, and malaria. This study investigated the phytochemical profile and antimicrobial activity of ethanol and ethyl acetate organic solvent extracts derived from the leaves, stems, and roots of Nauclea latifolia collected in Sierra Leone. Standard phytochemical screening revealed abundant secondary metabolites, including alkaloids, saponins, tannins, flavonoids, glycosides, and triterpenes, with ethanol extracts demonstrating the highest diversity and concentration. Thin-layer chromatography confirmed distinct bioactive compound patterns across plant parts. Antimicrobial assays against Klebsiella spp., Staphylococcus aureus, and Escherichia coli showed significant inhibitory effects, with ethanol extracts exhibiting superior activity, particularly against S. aureus (zone of inhibition: 17 mm). These findings validate the traditional medicinal uses of Nauclea latifolia and underscore its potential as a source of novel antimicrobial agents. The study advocates for further isolation and characterization of bioactive constituents, alongside safety and efficacy evaluations, to support integration of this plant into modern therapeutic applications in resource-limited settings.