Antibacterial Activity of Selected Medicinal Plants Used in Traditional Medicine in Taraba State

Traditional medicine practitioners across Nigeria's North East zone rely extensively on locally sourced plant materials to manage infectious diseases, yet the scientific validation of antibacterial efficacy for many of these plants remains limited. This study evaluates the antibacterial activity of five selected medicinal plants used by traditional healers in Taraba State, North East Nigeria, against common clinical bacterial isolates. Plants investigated include Azadirachta indica, Moringa oleifera, Terminalia avicennioides, Vitex doniana, and Senna siamea, selected based on ethnobotanical surveys conducted with 20 traditional medicine practitioners in Jalingo and Gashaka local government areas. Crude ethanolic and aqueous extracts were prepared from leaf, bark, and root samples. Antibacterial activity was assessed using the agar well diffusion method against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Minimum inhibitory concentrations (MIC) were determined by broth microdilution. Azadirachta indica leaf extract demonstrated the broadest-spectrum activity with MIC values of 0.78 mg/ml against Staphylococcus aureus and 1.56 mg/ml against Escherichia coli. Moringa oleifera showed notable activity against gram-positive organisms. Aqueous extracts generally showed weaker activity than ethanolic preparations. The study provides scientific evidence supporting selected ethnomedicinal plant use in Taraba and recommends further phytochemical characterisation and in vivo validation studies. Keywords: medicinal plants, antibacterial activity, Azadirachta indica, Taraba State, ethnomedicine