Anti-Quorum Sensing and Antibacterial Activity of Rumex alveolatus

[Background]Infections caused by resistant bacteria are spreading so that efficacy of antibiotics in curing diseases has decreased. Therefore, many attempts are made to find new active compounds of plant origin as suitable substitutes. This research intended to identify active compounds with antibacterial and anti-quorum sensing activities of aqueous and methanol extracts of Rumex alveolatus against a number of bacteria.[Methods]This empirical study was conducted against some of pathogenic bacteria. Using the Soxhlet method, extracts of R. alveolatus leaves and roots were prepared and antimicrobial effects of the extracts were evaluated by well diffusion method. Anti-quorum sensing activity of the methanol extract of R. alveolatus against pyocyanin production, proteases production and biofilm formation were also investigated. The active compounds in R. alveolatus were identified using the gas chromatography-mass spectrometry method.[Results]The inhibition zone produced by the methanol leaves extract at 500 mg/mL against P. aeruginosa, S. aureus, and S. typhi were 22.8 ± 0.8, 10.7 ± 1.3, and 12.1 ± 1.0 mm, respectively. The MICs and MBCs of the methanol leaves and roots extracts of this plant for P. aeruginosa, S. aureus, and S. typhi were similar, 125 and 250 mg/mL, respectively. The main phenolic compound obtained from R. alveolatus was 1, 2-benzenedicarboxylic acid (89.68%). The methanol leaves extract of R. alveolatus at 62.5 mg/mL prevented biofilm formation by P. aeruginosa and S. aureus and, when applied at 62.5 mg/mL, reduced pyocyanin production in P. aeruginosa by up to 66 percent. The aqueous extracts of R. alveolatus had not antibacterial and anti-quorum sensing activity.[Conclusions]The methanol extracts of Rumex alveolatus had antibacterial and anti-quorum sensing activity.