In Vitro Antimicrobial Activities of Four Medicinally Important Plants of Bangladesh

Abstract

In this study, methanolic crude extracts and their different fractions i.e. hexane, carbon tetrachloride, dichloromethane and aqueous soluble fractions of the B. daigremontianum(Raym.), C. cordifolia, (Linn.), L. glutinosa(Laur.) and M. minutum(G. Forst.)were subjected for antimicrobial activity. All the fractions were tested against different gram positive and gram negative bacteria and fungi to find out their antimicrobial activity. This study showed that among different fractions of the four important medicinal plants, carbon tetrachloride fraction and crude methanol soluble fraction of leaves' extract of L. glutinosa showed significant activity against gram positive bacteria, gram negative bacteria and fungi at a dose of 400 μg/ disc. Leaves' extract of B. daigremontianum showed mild to moderate antimicrobial activity, especially dichloromethane solvent extract showed significant antimicrobial activity showing 10-13 mm zone of inhibition in diameter, against Shigelladysenteriaethe extract showed highest activity (13 mm). Carbon tetrachloride extracts of leaves' extract of L. glutinosa showed significant antimicrobial activity which ranged from 11-16 mm zone of inhibition. For extract of M. minutum, dichloromethane solvent extract showed marked antimicrobial activity ranging from 9-13 mm zone of inhibition in diameter. Kanamycin at a concentration of 30 μg/dise was used as positive control in this study.