PHYTOCHEMICAL CONSTITUENTS AND ANTIMICROBIAL ACTIVITIES OF METHANOLIC EXTRACTS OF Polyalthia longifolia AND Annona senegalensis PLANTS

Abstract

This study investigates the phytochemical profile and antimicrobial potential of methanolic extracts of Polyalthia longifolia and Annona senegalensis, medicinal plants extensively used in African traditional medicine. The extracts underwent preliminary phytochemical screening to detect the presence of secondary metabolites, including alkaloids, flavonoids, tannins, saponins, phenolics, terpenoids, steroids, glycosides, and anthraquinones using standard protocols. The antimicrobial activity of the extracts was assessed against Escherichia coli, Salmonella typhi, Bacillus subtilis, and Candida albicans using the agar well diffusion method. Qualitative phytochemical screening revealed the presence of alkaloids, flavonoids, glycosides, phenols, tannins, saponins, steroids, and terpenoids in different plant parts. Extracts of P. longifolia, particularly stem bark and root, exhibited broad-spectrum antimicrobial effects with zones of inhibition ranging from 21.0–27.0 mm, in some cases exceeding the efficacy of standard antibiotics. A. senegalensis root extract showed moderate antibacterial effects but was most active against C. albicans. These findings substantiate the traditional use of these plants and indicate the potential of their phytoconstituents for the development of novel antimicrobial agents