In vitro evaluation of pomegranate (Punica granatum L.) peels antibacterial activity against bacteria responsible of diabetic foot infections

Abstract

Diabetic foot infections are common complications of diabetes. Antibioresistant bacteria are associated with a higher incidence of lower-limb amputation. Punica granatum L. is one of the plants used by many civilisations in the treatment of infectious maladies. Our work consists of evaluating in vitro the antibacterial activity of three extracts of pomegranate peels on Gram positive and Gram negative bacterial strains isolated from diabetic foots pus. The active molecules were obtained by maceration of pomegranate peel powder in ethanol/water (30/70) and fractionation using three solvents: dichloromethane (EDCM), ethyl acetate (EEA)  and the n-Butanol (En-BuOH). The bacterial susceptibility to the extracts was determined using  the disks diffusion test and the Minimal Inhibitory Concentration (MIC) by dilution in liquid medium using sterile microplates. The three extracts were active against the tested strains with maximum activity of the extract (En-BuOH) against Staphylococcus epidermidis (35.3 ±0.3 mm). Enterobacter aerogenes was less sensitive to the extracts (EDCM) and (EEA) (9±0.9 and 9.6±0.6 mm respectively). The weakest MIC (0.12 mg/ml) was recorded within Morganilla morganii with the three fractions and within Proteus mirabilis with the fraction ethyl acetate. Furthermore, the highest MIC (> 250 mg/ml) was fond within Staphylococcus aureus and Enterobacter aerugenes with dichloromethane, Escherichia coli and Pseudomonas aeruginosa with different fractions. More of that, the extracts were characterised by an antibacterial activity better than some used antibiotics to whom the strains were  multiresistant.