• Zumaana Rafiq Dr Mgr Educational and Research Institute
  • Magesh Haridoss
  • Rosy Vennila


Objective: With a rise in multidrug resistant (MDR) bacterial isolates, search for antibiotics or compounds that could act synergistically with them
is a significant area of research. Efflux-mediated resistance, in particular, is a great hurdle that needs to be overcome. In an effort to identify such
synergistic compounds and potential efflux pump inhibitors (EPI), we analyzed the rind of Punica granatum (pomegranate) against MDR clinical
Klebsiella pneumoniae isolates.
Methods: Sequential fractionation of P. granatum rind ethanol (PGR) extract was carried out to obtain hexane, butanol and water fractions.
Antibacterial activity of the plant extracts was confirmed, and synergistic interaction with antibiotics was determined by the checkerboard assay. Gas
chromatography-mass spectrometry (GC-MS) analysis was performed to identify the phytochemical constituents of the hexane extract. To study EPI
activity of the extracts, norfloxacin accumulation assay was carried out.
Results: PGR ethanol extract was found to have synergistic activity with ciprofloxacin, levofloxacin, ceftazidime, cefoxitin, meropenem, and gentamicin
resulting in fold decrease of minimum inhibitory concentration (MIC) ranging from 2 to 32 fold. The hexane fraction was found to have maximum
synergistic activity resulting in a 32-fold reduction of ciprofloxacin MIC followed by butanol and water fractions. The PGR ethanol extract was also
found to have efflux inhibition activity by the norfloxacin accumulation assay. Of the sequential fractions, the butanol fraction had maximum efflux
inhibition activity.
Conclusion: Therefore, our study shows that PGR extract can potentiate the effect of antibiotics on MDR bacteria, and the mode of action is likely to
be due to EPI.
Keywords: Punica granatum rind, Pomegranate, Synergy with antibiotics, Multidrug resistant, Klebsiella pneumoniae, Efflux pump inhibition.


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Fig. 2: Efflux inhibition activity of Punica granatum rind ethanol extract and sequential fractions
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How to Cite
Rafiq, Z., S. NARASIMHAN, M. Haridoss, R. Vennila, and R. VAIDYANATHAN. “PUNICA GRANATUM RIND EXTRACT: ANTIBIOTIC POTENTIATOR AND EFFLUX PUMP INHIBITOR OF MULTIDRUG RESISTANT KLEBSIELLA PNEUMONIAE CLINICAL ISOLATES”. Asian Journal of Pharmaceutical and Clinical Research, Vol. 10, no. 3, Mar. 2017, pp. 191-5, doi:10.22159/ajpcr.2017.v10i3.16000.
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