IN-VITRO ANTIBACTERIAL EFFICACY OF VITELLARIA PARADOXA EXTRACT AGAINST HUMAN CUTANEOUS BACTERIAL ISOLATES IN OYO STATE, NIGERIA: IMPLICATIONS FOR DERMATOLOGICAL ETHNOMEDICINE

Antibiotic resistance is spreading faster than new treatments are appearing, which has pushed researchers toward plant-derived options that traditional medicine has long relied on. Vitellaria paradoxa C.F. Gaertn. (Shea butter tree) is traditionally used in West African medicine for skin ailments, yet rigorous evidence of its killing activity against bacteria that actually live on human skin is still thin. This study evaluated the in-vitro antibacterial efficacy of V. paradoxa extract dissolved in dimethyl sulfoxide (DMSO) against skin bacterial flora, using the agar-well diffusion method at four concentrations (300, 150, 75, and 32.5 mg/L). Skin swabs were collected from four healthy volunteers at Ajayi Crowther University, Oyo, Nigeria. Bacteria were isolated on nutrient agar and characterised by colonial morphology, Gram-staining, and biochemical tests. Eighteen Gram-positive isolates were recovered: Bacillus spp. (38.9%), Corynebacterium spp. (27.8%), Staphylococcus aureus (11.1%), Staphylococcus epidermidis (11.1%), and Staphylococcus spp. (11.1%). At 300 mg/L, 77.8% (14/18) of isolates were susceptible, with the highest zone of inhibition (35 mm) recorded for Bacillus spp. All Bacillus spp. were susceptible, while both S. epidermidis isolates exhibited complete resistance, and a dose-dependent inhibition pattern was observed. V. paradoxa extract showed clear killing activity against Gram-positive skin organisms, notably Bacillus spp. and S. aureus, supporting its ethnomedicinal use in dermatology. The resistance of S. epidermidis points to biofilm-related defence as a likely explanation worth investigating further.