Polyphenols from Salix tetrasperma Impair Virulence and Inhibit Quorum Sensing of Pseudomonas aeruginosa

Abstract

Bacterial resistance represents one of the emerging obstacles in plants, animals, and humans that impairs treatment with antibacterial agents. Targeting of the bacterial quorum sensing system is one of the strategies to overcome this problem. Recently, research has been focused on natural and food components which can function as quorum sensing inhibitors. In this study, a methanol extract from Salix tetrasperma stem bark was phytochemically profiled by LC-MS analysis. This resulted in the identification of 38 secondary metabolites with (epi)catechin-(epi)catechin, epicatechin, tremulacin, salicortin, and trichocarposide as the major constituents. The extracts of both stem bark and the previously profiled flower of S. tetrasperma were tested for anti-quorum sensing activity in a common and widely distributed pathogen Pseudomonas aeruginosa. The natural products inhibited swimming and swarming motilities, as well as proteolytic and hemolytic activities in a dose-dependent manner. Molecular docking of the constituents from both extracts against the quorum sensing controlling systems Lasl/LasR, rhll/rhlR, and PQS/MvfR showed that epicatechin, (epi)catechin-(epi)catechin, p-hydroxy benzoyl galloyl glucose, p-hydroxy benzoyl protocatechuic acid glucose, and caffeoylmalic acid could be the main active components. This study supports the importance of secondary metabolites, especially polyphenols, as quorum sensing inhibitors.

Paeonol Attenuates Quorum-Sensing Regulated Virulence and Biofilm Formation in Pseudomonas aeruginosa

“… Snoussi et al (2018) have reported that the essential oils and phenolics of Carum copticum inhibit violacein production. Similar results also have been reported for the phenolic compounds from plants ( Mostafa et al, 2020 ). There are three QS systems in bacteria: the LuxR/I-type systems, typically used by Gram-negative species, in which the signaling molecule is an N -acyl L -homoserine lactone (AI-1); the small oligopeptides (AIP) systems, typically used by Gram-positive species; and the LuxS/furanone metabolites (AI-2) interspecies signaling systems ( Galloway et al, 2011 ; Hawver et al, 2016 ).…”

Phytochemical Profiling of Lavandula coronopifolia Poir. Aerial Parts Extract and Its Larvicidal, Antibacterial, and Antibiofilm Activity Against Pseudomonas aeruginosa

“…The extract inhibited the biofilm formation of P. aeruginosa in a dose-dependent manner and ranged from 17 to 38% ( Figure 5 ). These considerable antibiofilm properties are similar to that of polyphenol-rich extract from the bark of Salix tetrasperma and the leaves of Annona glabra and Gynura procumbens [ 54 , 55 , 56 ]. A recent study by Koely et al described the antibiofilm activities of Enydra fluctuans against P. aeruginosa .…”

HPLC-PDA-ESI-MS/MS Profiling and Anti-Biofilm Potential of Eucalyptussideroxylon Flowers

“…The inhibition of biofilm is considered an important way for the treatment of bacterial infections [8]. Searching for bacterial virulence factors inhibitors is very important due to the well-known ability of pathogens to develop different mechanisms of antibiotics resistance.…”

“…Plant extracts have been reported to regulate biofilm formation and inhibit quorum sensing (QS) [5]. Various studies have explored different natural secondary metabolites to prevent the formation of biofilms in Gram-negative and Gram-positive bacteria, in addition to the dimorphic pathogenic yeast [4,[6][7][8].…”