Phytochemical Profiling and Antimicrobial Activity of Selected Ethiopian Medicinal Plants: Comparative Evaluation of Solvent Extracts Against Bacterial and Fungal Pathogens

Objective This study evaluated the phytochemical composition and antimicrobial activity of selected Ethiopian medicinal plants traditionally used for the treatment of infectious diseases. Leaves of Rhamnus prinoides , Croton macrostachyus , and Vernonia amygdalina were extracted using methanol, ethanol, and acetone solvents. Methods Preliminary phytochemical screening revealed the presence of bioactive compounds including alkaloids, terpenoids, flavonoids, tannins, saponins, steroids, and phenolics. Antimicrobial activity was assessed against selected bacterial ( S. aureus, S. pneumoniae, S. pyogenes, E. coli, P. aeruginosa ) and fungal ( C. albicans, A. flavus, A. niger Trychophyton spp., Cryptococcus spp. ) strains using the standard agar disc diffusion method, followed by determination of minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) using standard microdilution techniques. Results Among the tested extracts, acetone extracts of V. amygdalina exhibited the highest antibacterial activity, with significant inhibition zones against S. aureus . MIC values ranged from 500 to 5000 µ/ml, and 500 to 6000 µ/ml indicating moderate to strong antibacterial and antifungal potency, respectively. Conclusion The findings support the ethnopharmacology usage of these plants and suggest their potential as sources of bioactive compounds for the development of alternative antimicrobial agents. Further studies on compound isolation, toxicity, and mechanism of action are recommended.