Abstract

IN VITRO ANTIBACTERIAL ACTIVITY AND MINIMUM INHIBITORY CONCENTRATION OF METHANOLIC EXTRACT OF MESUA FERREA L. FLOWERS AGAINST PATHOGENIC BACTERIA

A. Rajasekaran*, B. Akshya

Abstract

Background: Mesua ferrea L. flowers have a history of use in traditional medicine and have been investigated for antimicrobial activity. Previous studies on different parts and extracts of the plant have reported activity against a range of Gram-positive and Gram-negative organisms. The present study evaluated the in vitro antibacterial activity of a methanolic extract of M.ferrea flower buds against ten bacterial strains representing both Gram-positive and Gram-negative organisms. Methods: Dried M. ferrea flower buds were extracted by cold maceration with methanol. Antibacterial activity was assessed by agar well diffusion, and the minimum inhibitory concentration (MIC) was evaluated by broth microdilution using two-fold serial concentrations from 1000 to 7.81 μg/mL. The bacterial strains and culture collection numbers were documented. Results: The methanolic extract produced inhibition zones against nine of the ten tested strains, with zones ranging from 16 to 28 mm; no inhibition was recorded for Bacillus subtilis. The largest inhibition zone was observed against Escherichia coli (28 mm), followed by Staphylococcus aureus (27 mm). MIC values ranged from 62.5 to 250 μg/mL. The lowest MIC (62.5 μg/mL) was observed against Pseudomonas aeruginosa and Micrococcus luteus, whereas the remaining susceptible strains showed MIC values of 125 or 250 μg/mL. Conclusion: The findings demonstrate measurable broad-spectrum antibacterial activity of the methanolic extract of M.ferrea flower buds, although the response varied among organisms and the tested organism panel represents only part of the broader antibacterial spectrum reported for this species in the literature. The present dataset supports further investigation of the extract and its bioactive constituents.

Keywords: Mesua ferrea; flower buds; methanolic extract; antibacterial activity; agar well diffusion; minimum inhibitory concentration; MIC.