The rise of gingerol as anti-QS molecule: Darkest episode in the LuxR-mediated bioluminescence saga.

The phenomenon of bioluminescence is the most widely investigated model of quorum sensing (QS) that occurs in various strains of Vibrio. Of lately, most of the virulence exhibited by other microbes is also attributed by similar quorum sensing pathways. Any leap towards blocking of such mechanisms is the need of the hour which is hypothesized to be achieved by interfering with normal QS interactions between ligands and their receptors. Gingerol, a pungent oil easily available from ginger is a structural analog of N-acylhomoserine lactone (AHL), which is an actual signalling ligand of QS-receptor LuxR responsible for initiating a cascade of reactions leading to bioluminescence. In-silico study suggested the antagonistic binding of gingerol to LuxR by hydrogen bonding and hydrophobic interactions which should, in theory, reduce bioluminescence. This was corroborated experimentally by rigorous image analysis of luminescence using hue, saturation and luminescence (HSL) values. Hence, we conclude gingerol as a potent QS-inhibitor for LuxR that may also inhibit the other members of AHL-receptor family.