Silencing Bacterial Communication: Quorum Sensing Inhibition by Cinnamon Extract

Abstract

Quorum sensing (QS) is a cell–cell communication system employed by many bacteria to coordinate population density–dependent physiological and pathogenic behaviors. Targeting QS has emerged as a promising anti-virulence strategy that does not exert direct selective pressure for resistance. The present study aimed to identify and evaluate quorum sensing inhibitory activity using Cinnamomum verum (cinnamon) extract. QS-interfering bacteria were isolated from environmental water samples using nutrient agar medium, followed by sub-culturing to obtain pure colonies. Molecular sequencing was performed to determine the taxonomic identity of the isolates. Cinnamon extract was prepared using 75% (v/v) methanol and assessed for antibacterial activity against the isolates by the agar well diffusion method on Mueller–Hinton agar. In addition, molecular interaction analysis was conducted to examine the binding relationship between the QS regulatory protein LasR and the bioactive compound cinnamaldehyde. The findings demonstrate that cinnamon extract exhibits notable quorum sensing inhibitory potential, supported by its interaction with LasR. These results suggest that cinnamon, a widely consumed spice, may serve as a natural quorum sensing inhibitor capable of attenuating bacterial virulence and pathogenesis, highlighting its potential application in antimicrobial and therapeutic strategies.