Phytochemical Characterization and Biological Activities of Anthocleista nobilis Bark Extracts Against...

Urinary tract infections (UTIs) caused by multidrug-resistant (MDR) bacteria are a major public health concern, especially in low-resource settings. This study evaluated the antibacterial and antioxidant activities of aqueous, hydroethanolic, and hydroacetonic bark extracts of Anthocleista nobilis, a medicinal plant traditionally used in Côte d'Ivoire to treat UTIs. Clinical isolates (Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus) were analyzed for antibiotic resistance and susceptibility to the extracts. Antibacterial activity was assessed using disc diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Antioxidant activity was measured using DPPH and ABTS radical scavenging methods. All isolates showed high resistance to β-lactams and fluoroquinolones, with methicillin-resistant S. aureus (MRSA) identified in 46% of strains. The hydroacetonic extract demonstrated the strongest bactericidal activity (MBC/MIC = 2 in 67% of strains), while the aqueous extract showed the highest ABTS antioxidant capacity. Phytochemical analysis revealed high levels of polyphenols, flavonoids, and tannins, with variations depending on the solvent used. These results support the traditional use of A. nobilis for UTI treatment and highlight its potential as a source of bioactive compounds for alternative or complementary therapies against MDR pathogens.