Quorum sensing inimical activity of Tribulus terrestris against gram negative bacterial pathogens by signalling interference

Bacterial virulence is controlled by a cascade of genes influenced by quorum sensing alias bacterial signalling.The present study was intended to develop an effective module that could constrain bacterial communication without harming the host. Quorum quenching ability of Tribulus terrestris was screened upon chromogenic reporter strains such as Chromobacterium violaceum, Serratia marcescens and Pseudomonas aeruginosa. Hydro-alcoholic extracts of root showed positive quorum quenching activity by effectively down regulating quorum sensing controlled mechanisms such as pigment production and biofilm formation. Lead component was purified and found to be s-1, 5-O-dibenzoyl ribofuranose by GC–MS NIST and NMR spectrometry. Interestingly it was observed that the compound was neither bactericidal nor bacteriostatic but rather it’s only disturbing its interaction. Further studies revealed that the antagonist is not inhibiting the production of signalling molecule acyl homoserine lactone, instead inhibiting its action.