Plant-Derived Inhibitors of Density-Dependent Communication in Bacteria: Diversity of Structures, Bioactivity Mechanisms, and Sources of Origin

This review summarizes the current data on plant-derived compounds that inhibit bacterial density-dependent communication (quorum sensing, QS). The most frequent types of QS are described and interpreted as promising targets for a new way of antimicrobial therapy directed at suppression of virulence factors production and biofilm formation. The methodology for screening of the plant-derived QS inhibitors and their in-depth analyses is described. Diversity of known inhibitors, which are terpenes and terpenoids, phenols and methoxyphenols, coumarins, flavonoids, sulfoxides and isothiocyanates, is shown. The effects of various plant-derived compounds on bacteria with different QS types are analyzed, and molecular mechanisms of anti-QS bioactivity are characterized. The taxonomy of plant sources of QS inhibitors and the bio-synthetic pathways of these secondary metabolites are discussed. A concept of suppression of bacterial density-dependent communication as a novel plant innate immunity component is presented, as well as of the possible application of plant-derived QS inhibitors for animal and human protection.