Phytochemical screening and evaluation of the antibacterial activity of Atractogyne bracteata (Rubiaceae) bark extracts

Medicinal plants are a valuable source of bioactive molecules, which are generally secondary metabolites. This study is part of the search for new natural molecules from a plant in the Tonkpi region. The plant in question is Atractogyne bracteata, belonging to the Rubiaceae family, and used in traditional medicine. Phytochemical screening revealed the presence of bioactive substances, namely polyphenols, flavonoids, saponins, and tannins. Antibacterial activity was assessed through a qualitative study (disc diffusion and wells), and the results were confirmed by a quantitative study that determined the MICs and MBCs of the studied extracts against six bacterial strains (ATCC Escherichia coli, ESBL Escherichia coli, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella and susceptible Klebsiella).The aqueous extract showed significant antibacterial activity against the tested strains, particularly P. aeruginosa, Staphylococcus aureus Meti-R and E. coli ESBL (Extended-Spectrum Beta-Lactamase), with inhibition zone diameters of 20 and 14 mm, respectively, at concentrations of 200 mg/ml. Minimum inhibitory concentration (MIC) values showed a wide range, from 3.12 mg/ml to 20 mm. This study supports the antibacterial properties attributed to this plant.