Attenuating Vibrio harveyi Virulence Through Quorum Sensing Interference Using Piperine: An In Vitro and In Silico Approach.

Aquaculture diseases caused by pathogens such as Vibrio spp., amplified by the emergence of antibiotic resistance, threaten the aquaculture industry. Due to its critical role in regulating the expression of genes related to antibiotic resistance and virulence, quorum sensing (QS) was proved to be an ideal target in disease control. In this study, we investigated the effects of the alkaloid piperine on the QS system of a fish pathogenic Vibrio harveyi strain. In vitro assays showed that piperine inhibits biofilm formation of V. harveyi without affecting their growth. Moreover, piperine specifically reduced QS activity in V. harveyi, as evident in the inhibition of biofilm and bioluminescence, likely through the AI-2 pathway. Molecular docking simulations showed significant binding energies between piperine and QS proteins-LuxP, LuxQ, LuxR and LuxS-revealing competitive inhibitory effects against LuxP, LuxR, and LuxS, and non-competitive interactions with LuxQ. This study demonstrated the effects of piperine against V. harveyi and elucidated its mechanism of action against V. harveyi QS, implying its potential application in aquaculture systems.