Abstract

Studies on the antibacterial activity and chemical constituents of the aqueous and methonolic leaf extracts of Khaya senegalensis and Ximenia americana were carried out using standard methods. Disc concentrations of 125, 250, 500 and 1000 µg/ml of the extracts were used against five bacterial isolates obtained from post-surgical wounds at the National Orthopaedic Hospital, Kano, Nigeria. Both extracts showed no activity against all the test bacteria. The minimum inhibitory concentration for both extracts was above 1000 µg/ml. Phytochemical screening showed the presence of saponins and absence of flavonoids in both the aqueous and methonolic extracts of K. senegalensis. Steroids and reducing sugars were found only in the methonolic extract while alkaloids and tannins were present only in the aqueous extract. In X. americana, flavonoids, steroids, tannins and reducing sugars were found in the methonolic extract while the aqueous extract revealed the presence of alkaloids, saponins and tannins. Although there was no activity of both extracts against the test bacteria, however, the presence of these chemical constituents signifies the potential of these plants as sources of therapeutic agents. This supports the traditional use of these plants in curing wound infections. It is therefore suggested that further studies be carried out using higher extract concentrations as well as to isolate, purify and identify the active compounds present in these extracts with a view to justifying these claims.

Key words: Phytochemistry, antibacterial activity, Khaya senegalensis, Ximenia americana, leaf extracts.