Phytochemical Screening and Antibacterial Activity of Ocimum gratissimum Leaf Extracts Against Wound Pathogens in Ibadan, South West Nigeria

Ocimum gratissimum, commonly called scent leaf, is extensively used in traditional wound care across South West Nigeria, particularly in peri-urban and rural settings in Ibadan where it is applied as a topical agent and wound compress for infected lacerations and ulcers. This study investigates the phytochemical composition and antibacterial activity of aqueous and ethanolic leaf extracts of Ocimum gratissimum against wound-associated bacterial pathogens. Fresh plant materials were collected from home gardens and local markets in Ibadan, Oyo State, dried under shade, and extracted using cold maceration. Wound swab samples were obtained from surgical wound infection cases at the University College Hospital, Ibadan, with isolates including Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Agar well diffusion and minimum inhibitory concentration assays were performed. Phytochemical screening detected flavonoids, terpenoids, saponins, tannins, and phenols. The ethanolic extract demonstrated significant activity against all tested pathogens, with the largest zones of inhibition (21 mm) recorded against S. aureus. MIC values ranged from 6.25 to 50 mg/mL. Eugenol and thymol, confirmed by GC-MS, were identified as probable contributors to the observed activity. These results support the rational development of Ocimum gratissimum-based topical antimicrobial formulations for wound care in resource-limited Nigerian communities. Keywords: Ocimum gratissimum, wound pathogens, antibacterial, Ibadan, phytochemical