Abstract

Ethanolic extracts of the stem bark, root bark and leaves of Terminalia avicennioides were assayed against Staphylococcus aureus, Escherichia coliand Pseudomonas aeruginosa obtained from patients suffering from complicated respiratory tract infections for their antimicrobial activity. Analysis of variance showed that the ethanolic extracts of the plant material exhibit a significant (P > 0.05) antimicrobial activity against S. aureus. The various zone of inhibitions onEscherichia coli was moderate (P < 0.05) at different concentrations, very low antimicrobial activity was observed against P. aeruginosa. Important bioactive agents like phenols, steroids, glycosides, flavonoids, tannins, ellagic acids were detected in the bark, leaves and root of T. avicennioides.  Anthraquinone was not absent in all the plant parts tested.  The bioactive constituents detected in T. avicennioides may be responsible for the observed antimicrobial activity of the plant and hence, its potential use as antimicrobial agent.

Key words: Antimicrobial activity, bacterial pathogens, Phytochemical, respiratory tract diseases, Terminalia avicennioides.