Evaluation of the Antimicrobial Potential of Punica Granatum Leaves Hydro-methanolic Extract against Selected Pathogens

For a long time, extracts of Punica granatumhave been used in alternative and complementary medicine. The object of the present study was to evaluate the activity of Punica granatumleaves hydro-methanolic extract against some Gram-positive, Gram-negative bacteria and Candida albicans using agar diffusion assay.The leaves yielded 34.7% of raw semisolid extract after maceration in hydro-methanol (50:50 v/v) andevaporation.After lyophilization, the dry powder was reconstituted in Muller-Hinton broth to get a concentration of 128 mg/mL; from which further 5lower concentrations have been prepared (64, 32, 16, 8, and 4 mg/mL in Muller-Hinton Broth).The extract exhibitedconcentration-dependent activity against some Gram-positive bacteria, namely,Listeria monocytogenes (20.67 ± 0.82), Clostridium perfringens (17.33 ± 0.52), Staphyllococcus aureus (10.5 ± 0.55), Bacillus cereus (8.83 ± 0.41), and Enterococcus fecalis (6.33 ± 0.52);and against three Gram-negative bacteria, namely, Shigellaflexneri (13.33 ± 0.8), Vibrio parahaemolyticus(12.17 ± 0.42) and Proteus vulgaris (8.5 ± 0.55);as well as against Candida albicans (15.8 ± 0.98); (the values are in mm after 128 mg/mL extract). However, the extract was without any visible activity againstEscherichia coli, Salmonella typhimuriumand Klebsiellaaerogenes.The minimum inhibitory concentrations (MICs) against susceptible organisms were1.06 mg/mL (Clostridium perfringens), 1.11 mg/mL (Vibrio parahaemolyticus), 2.08 mg/mL (Staphyllococcus aureus), 2.16 mg/mL (Bacillus cereus),2.76 mg/mL (Candida albicans), 3.07 mg/mL (Listeria monocytogenes), 3.80 (Shigella flexneri), 12.92 mg/mL (Proteus vulgaris) and 15.55 (Enterococcus faecalis)