Evaluation of antimicrobial activities of some Bangladeshi medicinal plants

Abstract

The crude methanol extracts of aerial parts of Abrus precatorius L., leaf of Magnolia pterocarpa Roxb., Dracaena spicata Roxb. and Ravenala madagascariensis Sonn. as well as their hexane, carbon tetrachloride, chloroform and aqueous soluble partitionates were subjected to screenings for disc diffusion assay. Among the test samples of A. precatorius, the highest zone of inhibition (15.0mm) was exhibited by the carbon tetrachloride soluble fraction against Pseudomonas aeruginosa. The M. pterocarpa extractives exhibited significant zone of inhibition ranging from 7.0 to 23.0mm against the test organisms. The highest zone of inhibition (23.0mm) was demonstrated by the carbon tetrachloride soluble fraction against Pseudomonas aeruginosa. This fraction also exhibited 20.0mm zone of inhibition against the gram positive bacteria Staphylococcus aureus and gram negative bacteria Vibrio parahemolyticus. Among the test samples of D. spicata, the highest (18.0mm) zone of inhibition was demonstrated by the aqueous soluble fraction against Pseudomonas aeruginosa. The test samples of R. madagascariensis exhibited weak antimicrobial activity with zone of inhibition ranging from 2.0 to 9.0mm.