Métabolites secondaires et activités biologiques des extraits de l’écorce de tronc de Khaya senegalensis, une plante à usage vétérinaire récoltée au Bénin

Abstract

: In Africa, and particularly in Benin, medicinal plants are the most widely used means of solving human and animal health problems. The Beninese flora is rich in plants used to treat gastrointestinal diseases of farm animals whose chemical and biological potentials are still unknown. It is to correct this insufficiency that the present work aims at the chemical and biological recovery of Khaya senegalensis. After phytochemical screening, the phenolic compound contents of Khaya senegalensis extracts were determined spectrophotometer. Antibacterial and antiradical activities were evaluated by microplate dilution methods and DPPH respectively. The active ingredients of K. senegalensis were characterized by GC/MS. Several metabolites have been identified. The crude extracts (ethanolic, hydroethanolic and aqueous extracts) of K. senegalensis showed a lower antiradical activity compared to ethyl ether (IC50=0.09 μg/ml) and ethyl acetate (IC50=1μg/ml) fractions, which are more active that BHA (IC50= 4.8μg/ml), quercetin (IC50=3μg/ml) which are synthetic compounds. From the antibacterial activity, it appears that the objective extracts and fractions of this plant have a bactericidal activity with respect to Escherichia coli and Klebsiella pneumoniae. From the results of the chromatographic analysis, it appears that the bark of K. senegalensis contains glycerol, glycerol ethanoate, pyrocatechol, octadecanamide and neoergosterone as major components. The diversity of metabolites, the anti-fungal and antibacterial activities of K. senegalensis, could justify the use of this plant in the veterinary pharmacopoeia in Benin