Quercetin from Cananga odorata – A Quorum quenching flavonoid inhibiting pyocyanin production in Pseudomonas aeruginosa

Authors :

Neethu Krishnan S, Sheetal Sivankutty, JayachandranK

 Abstract:

Quorum sensing is a phenomena of cell density mediated regulation of bacterial gene expression that can control the virulence factors causing pathogenesis.Acyl Homoserine Lactones (AHL) are a group of signaling molecules that regulate quorum sensing i n Gram negative bacteria resulting in the control of biofilm formation, pyocyanin production, twitching motility and proteolysis activity.In the present study the pyocyanin pigment was produced from Pseudomonas aeruginosa and was characterized by TLC,FT/IR, and LC/MS. Further an attempt was made to extract and purify possible quorum quenching compound from the ethyl acetate extracts of a highly aromatic and terpenoid containingCanangaodorataflower. The extract after characterization with gradient flash chromatography,TLC, FTIR and LCMS ,was found to contain quercetin, a riboflavin like flavanoid .The effect of this plant extract containing quercetin on pyocyanin pigment production in Pseudomonas aeruginosa was evaluated. It could be established that even though the plant extract did not cause any significant inhibition on bacterial growth it inhibited the quorum sensing based pyocyanin production in the bacteria. The quorum quenching properties of Canangaodorataflower extract carrying quercetin can therefore be considered as a potential therapeutic strategy against Pseudomonas aeruginosa mediated infections as this pigment production is a pathogenesis linked property.