Abstract:
Antibacterial activity of the methanol extract of fruit peel of Punica granatum
Linn (Family: Punicaceae) was evaluated against two Gram positive and two Gram negative
bacteria. The Gram positive bacteria included Staphylococcus aureus, Streptococcus
pneumoniae and the Gram negative organisms included Escherichia coli and Pseudomonas
aeruginosa respectively. The culture media used for antibacterial assay was Mueller Hinton
agar for the growth of S. aureus, E. coli and P. aeruginosa. The media used for the growth of
S. pneumoniae was Mueller Hinton blood agar. The antibacterial assay was performed
through Disc diffusion technique. The methanol extract was tested at three different
concentrations (50, 100 and 200 mg/ml). Standard antibiotic discs containing vancomycin (30
μg) for S. pneumoniae, penicillin (10 units) for S. aureus, ceftriaxone (30 μg) for E. coli and
ciprofloxacin (5 μg) for P. aeruginosa were used for the activity comparison. The results of
the study revealed that the extract possesses antibacterial activity against S. aureus,
S. pneumoniae and P. aeruginosa at all tested concentrations. The maximum zone of
inhibition of 19 mm of the extract at 200 mg/ml was observed against S. pneumoniae.
However, no zone of inhibition was observed against E. coli at the tested concentrations of
the extract. Based on the results obtained in this study, it may be concluded that the fruit peel
of P. granatum possess broad spectrum of antibacterial activity against a number bacteria.