Antimicrobial and Cytotoxic Properties of Leaf and Stem Bark Extracts of Faidherbia albida

This study evaluated the antimicrobial, cytotoxic and phytochemical properties of Faidherbia albida leaf and stem bark extracts. The methanolic extract of the plant parts was obtained and screened for phytochemical properties according to standard techniques. The antibacterial activities of the plant extract were investigated against ten clinical isolates using the agar well diffusion method while its cytotoxic potentials were assessed in accordance with established procedures. Flavonoids, tannins, alkaloids, saponins, glycosides, triterpenes, xanthoproteins, and anthraquinones were present in the leaf and stem bark extracts, and the extracts exerted antibacterial activities against the isolates with zones of inhibition showing no statistical difference from that of the positive control (p = 0.089). The minimum inhibitory concentrations of stem bark and leaf extracts ranged from 0.781 to 6.25 mg/ml and 0.472 to 6.43 mg/ml, respectively, while their minimum bactericidal concentrations ranged from 0.391 to 1.562 mg/ml and 0.290 to 1.782 mg/ml, respectively. There was no statistical difference between the activities of stem bark and leaf extracts (p > 0.106). The cytotoxicity test against the human embryonic kidney (HEK) 293 cells showed that the leaf and stem bark extracts were toxic at 0.1059 and 0.1179 μg/ml, respectively. The relatively high therapeutic indexes (TI) of the plant extracts indicated their safety. This study revealed that the leaf and stem bark extracts of F. albida possess robust antibacterial and cytotoxic properties that could be exploited in the treatment of related diseases and curtail further spread of antimicrobial-resistant pathogens.