Microbial Biofilm and Quorum Sensing Inhibition: Endowment of Medicinal Plants to Combat Multidrug-Resistant Bacteria

Continued emergence and spread of multidrug-resistant bacteria behooved the development of alternative treatment strategies, including antimicrobial drugs. A hopeful approach is to target cell-to-cell communications, commonly known as quorum-sensing (QS) and microbial biofilm formation. Quorum Sensing is a method used on bacteria to determine their physiological behavior and coordinate gene expression based on the cell to cell signaling. Many physiological functions of bacteria are controlled by quorum sensings such as virulence, motility, sporulation, luminescence, and biofilm formation. Microbial biofilms are organized aggregations of cells attached to a substratum and surrounded by a self-produced extrapolymeric substance (EPS) matrix. Currently, biofilm formation and quorum sensing are considered as a prospective novel target for antimicrobial therapy to control multi-drug-resistant infections. Plant-based natural products have been comprehensively studied in this context. In this review, a comprehensive overview of various research papers published in the last decade on plant-derived molecules that are capable of inhibiting quorum sensing or microbial biofilm formation is reviewed, mentioning the biosynthetic classes of active compounds and their biological activity in the performed assays.