Selected phytochemical bioactive compounds as quorum sensing inhibitors

Abstract

Bacterial infections remain an important problem for human health. The control of bacterial infections has been traditionally treated by inhibiting microbial growth using different types of antibiotics. However, the ability of different bacteria to resist the inhibitory action of antibiotics has become a global problem. In fact, there is an important need for the development of new antimicrobials that act on novel bacterial targets. Many pathogenic bacteria control their population and regulate gene expression in response to their cell population density using diffusible signalling com¬pounds. This type of communication has been referred to as “quorum sensing” (QS). This phenomenon can be essential for the synchronization of the virulence production factors, which make it an attractive therapeutic target. Therefore, the search of non-toxic compounds, which inhibit QS and so, the virulence of pathogenic bacteria can bring new alternatives for the treatment of bacterial infections in humans. In this work, we made an attempt to screen the anti-QS activity of 11 bioactive compounds extracted from fruits and vegetables using the biosensor strain, Chromobacterium violaceum. The anti-QS activity was determined quantifying the violacein production of the biosensor strain at three concentrations (50, 100 and 200 µg/ml). At least five of the tested compounds (cinnamaldehyde, pomegranate extracts, ellagic acid resveratrol and rutin) showed anti-QS activity against the biosensor strain. The obtained results showed the potential of bioactive compounds extracted from fruits and vegetables to be used as a new category of anti-pathogenic compounds against bacterial infections.