This study aimed to evaluate the effectiveness of Cynomorium coccineum extract on several quorum sensing dependent mechanisms, including biofilm formation, the production of virulence factors, and the production of autoinducers in Pseudomonas aeruginosa. The impact on biofilm formation has been evaluated using a crystal violet assay and visualized using a light microscope and scanning electron microscope. The effect of the extract on swarming motility, aggregation, hydrophobicity, and exopolysaccharide production has been investigated. The ability of the extract to suppress the production of P. aeruginosa virulence factors, including pyocyanin, rhamnolipids, protease, and chitinase, has been evaluated. The antiquorum sensing mechanism was evaluated in P. aeruginosa by determining the effect on the production of acyl homoserine lactone, and Chromobacterium violaceum, to produce a violacein pigment. The chemical composition of the extract was analyzed using liquid chromatography mass spectrometry (LC-MS). The results of LC-MS analysis showed that C. coccineum extract is rich in quercetin and palmitic acid. The lowest concentration that inhibits 50% of P. aeruginosa’s ability to form biofilm (MBIC50) is 0.39 mg/mL. The extract at 0.78, 0.39, and 0.2 mg/mL exhibited a significant reduction in swarming motility, aggregation ability, surface hydrophobicity, and exopolysaccharide production. At these concentrations, the extract significantly suppressed the production of pyocyanin, rhamnolipids, protease, and chitinase. The ability to inhibit the production of violacein and acyl homoserine lactone indicated the anti-quorum sensing activity of C. coccineum extract. In conclusion, C. coccineum extract can be considered a promising candidate to be developed as an anti-infective drug.
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