Anupma Malik, Sheema Bai, Leena Seasotiya, Pooja Bharti and Sunita Dalal
The study was aimed to study the efficacy of P. granatum ethyl acetate extract against multi drug resistant bacterial strains and to characterize the compounds at tributing synergistic and antibacterial potential by GC-MS analysis. Bacterial strains were screened for antibiotic resistance by the disk diffusion method. Antibacterial and synergistic activities of extract were explored by agar well diffusion method and microdilution method respectively. Synergy testing was carried out with antibiotics amikacin, ampicillin, ciprofloxacin, erythromycin, lincomycin, nitrofurantoin, tetracycline and trimethoprim. The extract was subjected to Gas chromatography and Mass spectroscopy (GC-MS) analysis to identify the bioactive compounds responsible for the studied activity. All the test bacterial strains were found to be multidrug resistant. Antibacterial studies showed that the ethyl acetate extract exhibited strong antibacterial activity with zone of inhibition and minimum inhibitory concentration ranged from 16-30 mm and 1.87 to 15 mg/ml respectively. The results of the synergistic studies revealed that good synergistic interaction was exhibited by the combination of the extract and antibiotic lincomycin and tetracycline. MICs of lincomycin and tetracycline were declined from 150 to 5μg/ml and 250 to 2.5μg/ml in combination with the peel extract. GC-MS revealed the presence of various medicinally significant phytochemicals like Citronellol, 5- Hydroxy methyl furfural and linoleic acid etc. Synergistic activity of P. granatum may be attributed to the different mode of action of the extract from the antibiotics. The findings provide substantial basis for future use of P. granatum ethyl acetate extract as potential antibacterial and antibiotic modulating agent.
