Evaluation of antibacterial activity of the crude and defatted methanol extracts of Eucalyptus Camaldulensis using spectrophotometric method

Abstract

This study was designed to explore new antibacterial agent(s) from the crude and defatted methanol extracts of Eucalyptus camaldulensis. The extracts were extracted by cold maceration, prepared, reconstituted and examined for their antibacterial activity using standard procedures. The extracts were challenged with pure clinical isolates of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Acinectobacter baumanii and Burkolderia cepacia viz-a-viz standard antibiotics of chloramphenicol, gentamicin and amoxicillin at 25 μg/ml, 50 μg/ml and 100 μg/ml concentrations using spectrophotometric method. Using the zone of inhibition as inhibitory parameter, both the crude and defatted methanol extracts of E. camaldulensis showed promising antimicrobial activity comparable to the standard antibiotics for all tested microorganisms. This research holds promise for the exploration of various potentially active secondary metabolites which would help in developing pharmaceuticals especially antibacterial drugs. The isolation and characterization of the exact metabolites responsible for these activities are therefore highly recommended.

Keywords: Antimicrobial, Eucalyptus camaldulesnsis, Spectrophotometric method