Phytochemical composition and antimicrobial, and anti-quorum sensing activities of Punica granatum L. methanolic extract

In this work, our aims were to investigate the antimicrobial resistance, and anti-quorum sensing activities of Punica granatum L. methanolic extract.

Antibacterial and antifungal activities were performed against thirteen bacteria and five fungal pathogens. Ultra-high performance liquid chromatography was used to identify the polyphenolic extract. The inhibition of pyocyanin production, proteolytic and elastolytic activity and swarming motility in Pseudomonas aeruginosa PAO1 test strain were estimated.

The methanolic extract from P. granatum L. was dominated by chlorogenic acid (34.028 mg/g), rutin (26.05 mg/g), epicatechin (12.207 mg/g), gallic acid (11.157 mg/g), and caffeic acid 9.768 mg/g). Results showed antibacterial activities against almost all tested microorganisms with mean diameter of growth inhibition zone ranging from 6 ± 0 to 30 ± 0 mm for Candida species and from 6 ± 0 to 22.66 ± 0.57 for bacterial strains. The lowest minimal inhibitory concentrations were recorded for Listeria monocytogenes ATCC 19115 and Salmonella enterica CECT 529 (0.14 mg/ml, respectively). The anti-quorum sensing activity of methanolic extract against P. aeruginosa showed a significant inhibition of swarming motility and an attenuation in virulence factors like pyocyanin production at low concentrations.

The obtained results indicates that P. granatum L. extracts is a rich source of phenolic compounds and highlighted the possibilities uses of pomegranate to attenuate the expression of quorum sensing controlled factors in P. aeruginosa PAO1 strain.