Phytochemical and In vitro Antimicrobial Activities of the Fruit Extracts of Xylopia aethiopica [Dun] A. Rich. (Annonaceae)

Aim: The fruit of the plant Xylopia aethiopica has been used in ethno-medicine in southern Nigeria for treating dysentery, cough and bacterial infections. This present study investigates the phytochemical and antimicrobial activities of the different extracts of X aethiopica fruit. Method: The powdered dried fruits of Xylopia aethiopica was extracted with 95% ethanol and further fractionated into n-hexane and ethyl acetate fractions. The clinically isolated strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans were obtained from their stock cultures and characterized using biochemical tests and then standardized with 0.5 McFarland. The antimicrobial activities of the different extracts were investigated using agar diffusion method. Results: The n-hexane extract was most effective against Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans with a minimum inhibitory concentration (MIC) of 6.25, 50 and 50 mg/ml respectively while the ethyl acetate extract was active against Pseudomonas aeruginosa and Candida albicans with MIC of 6.25 and 12.5 mg/ml respectively. The crude ethanol extract showed most activity against Pseudomonas aeruginosa with MIC of 3.125 mg/ml. The phytochemical studies on the crude extract revealed the presence of triterpenoids /steroids, carbohydrates, cardenolides and saponins. Conclusion: The antimicrobial activities of the plant justify its usage in traditional healthcare practices especially in infections involving Pseudomonas aeruginosa which showed the highest sensitivity.