A comparative study of the antibacterial activity of the ethanolic extracts of Vitex negundo L., Fragaria vesca L., Terminalia arjuna and Citrus maxima

Abstract

Objective:-To study and compare the antibacterial activity of the ethanolic extracts of Vitex negundo L. (EEVN), Fragaria vesca L. (EEFV), Terminalia arjuna (EETA) and Citrus maxima (EECM) on Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Methods:-The ethanolic plant extracts were prepared from the bark of Terminalia arjuna and leaves of Fragaria vesca, Vitex negundo and Citrus maxima by percolation method. Clinical isolates of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were obtained from the Department of Microbiology, Assam Medical College & Hospital. Disc diffusion method for antimicrobial susceptibility testing was performed according to the Kirby Bauer method. The whatman-1 filter paper discs of 6mm sizes impregnated with the plant extracts were placed on MuellerHinton agar plates seeded with bacterial cultures of 0.5 Mc Farland standard. Ciprofloxacin (5µg/disc) was used as positive control. The antibacterial activities were assessed by the presence or absence of inhibition zones after incubating the plates at 37 0 c for 24 hours. Results:-The ethanolic extracts of Vitex negundo (EEVN), Fragaria vesca (EEFV) and Terminalia arjuna (EETA) showed significant activity against Staphylococcus aureus. Ethanolic extract of Citrus maxima (EECM) and EEFV showed zones of inhibition for Pseudomonas aeruginosa. Staphylococcus aureus was maximally inhibited by EEVN. Escherichia coli were maximally inhibited by EEFV. Maximum zone of inhibition for Pseudomonas aeruginosa was shown by EECM. EEVN and EETA showed no antibacterial effect against Pseudomonas aeruginosa. EECM showed no antibacterial activity for Staphylococcus aureus. Conclusion: The plant extracts showed significant antibacterial activity against the selected microorganisms.