Abstract

Punica granatum are utilized by local people as the part of their meal. Peoples supposed to consume Punica granatum seed and their peel was thrown as waste. Present study was designed to evaluate the antibacterial activity of the DMSO, ethanol and methanol extracts of Egyptian and Taif cultivars of Punica granatum peel and seeds extracts against five opportunistic pathogens namely Staphylococcus aureus, Pseudomonas sp. and Bacillus sp. (as a gram positive bacteria) and Escherichia coli and Aeromonas hydrophila (as a gram negative bacteria). The antimicrobial activity of plant peels and seeds extracts were compared with that of Streptomycin, as reference antibiotics. Evaluations were based on the zone of inhibition using agar well diffusion assay. The inhibitory activity was found to be dose dependent. The methanol extract of the peels from the two cultivars at 15 mg/ml dosage were found to be active antimicrobials against all the test microorganisms. While, the maximum antimicrobial activity for the seeds extracts were reported at 60 mg/ml. Escherichia coli was reported to have significant susceptibility against most of the extract followed by Staphylococcus aureus and Pseudomonas sp. Additionally, we evaluated the effect of the peels and seeds extract on the DNA damage of the bacterial genome using the repetitive element PCR analysis technique (Rep-PCR). The Rep-PCR results significantly showed that there are a polymorphic numbers of genetic bands, which were found in E. coli treated bacteria and absent in the untreated bacteria. This study indicates that aqueous DMSO, methanol and ethanol extracts of peels and seeds of the two cultivars of Punica granatum may be utilizes as a potential source of antimicrobial and mutagen agents.

Key words: Punica granatum, antibacterial activity, Peels and seeds extracts and Rep-PCR.