The Ethnobotanical Survey, Antibacterial Activity and Phytochemical Screening of Extracts of Prosopis africana (Guill. & Perr.) Taub

Aims: To investigate the ethnomedicinal uses of Prosopis africana (Guill. & Perr.) Taub and to screen the antimicrobial property as well as determine the phytochemical constituents of leaves, stems and root bark. Study Design: Ethnobotanical surveys, antibacterial activity and phytochemical screening of extracts of P. africana. Place and Duration of Study: The ethnobotanical survey was conducted during June 2015 in Zounweogo Province. The experiments were conducted at the Department of Medicine and Traditional Pharmacopeia-Pharmacy (MEPHATRA-PH) of the Institute of Research in Health and Laboratory of Applied Biochemistry and Chemistry (LA.BIO.C.A), University Joseph KI-ZERBO. Methodology: The semi-structured questionnaires were administrated to 36 traditional healers and elucidated out on the ethnomedicinal uses of P. africana in treating bacterial infections, the plant parts used and the mode of administration. The antimicrobial activity of different polar extracts of the leaves, the stem and root were evaluated by using the agar diffusion method and the determination of the minimal inhibitory concentration (MIC) of extracts via microdilution method. The phytochemical constituents of all extracts were also screened air Ciulei method. Results: The traditional healers consisted of 64% women and 36% men were surveyed.                 P. africana is used to treat tooth decay, childhood diarrhoea and chronic wounds. Leaves and the stem bark are the most commonly used plant part in treating bacterial infections while the roots are primarily used for other therapeutic purposes. The main method of administration was decoction. Methanol extracts of the leaves showed better antibacterial activity on all bacterial strains than aqueous extracts: Escherichia coli ATCC 25922 (MIC = 390 µg/ml; diameter of inhibition = 13.00 ±1.00 mm), Staphylococcus aureus ATCC 25923 (MIC = 390 µg/ml; diameter of inhibition = 12.33 ± 1.53 mm), Escherichia coli ATCC 35218 (MIC = 3120 µg/ml; diameter of inhibition = 13±1,00 mm), Pseudomonas aeruginosa PAO1 (MIC = 12500 µg/ml; diameter of inhibition = 12.33±0.58 mm). Alkaloid salts, tannins, sterols and triterpenes, saponosides, flavonic glycosides and leucoanthocyans were found in extracts of the leaves, as well as in the barks of the stem and root. Conclusion: These results demonstrated that P. africana is a potent source of antimicrobial compounds and could justify its traditional use of in the folklore medicine of Zounweogo Province.