Exploring the anti-quorum sensing potential of synthetic lipstick dyes against Pseudomonas aeruginosa.

Lip care products such as balms, glosses, and lipsticks are widely used to enhance lip health, appearance, and protection. Lipsticks provide aesthetic appeal, social and psychological benefits, that act as a protective barrier against environmental stressors. However, growing concerns have emerged regarding chronic lip infections associated with multidrug-resistant bacteria, particularly Pseudomonas aeruginosa. This is especially concerning in individuals with conditions such as juvenile bullous pemphigoid, hypochromic microcytic anemia, and sickle cell trait. The persistence of P. aeruginosa is largely attributed to its quorum sensing systems, which regulate its virulence. This study explores the anti-QS potential of synthetic dyes found in lipsticks, such as acid red 92, brilliant blue FCF, eosin yellow, titanium dioxide, and carmine, against P. aeruginosa. By the broth dilution method, the minimum inhibitory concentrations (MICs) and sub-MIC levels were determined, and the effects on virulence factors, such as biofilm, pyocyanin, elastase, and rhamnolipid, were assessed by biochemical assays. Further, biofilms formation was visualized using confocal laser scanning microscopy, and gene expression analysis revealed a significant QS inhibition by acid red 92. In-silico analysis by molecular docking studies inferred the potential binding of the dyes with the QS-regulating proteins. Thus, our findings highlight acid red 92 as a promising candidate for therapeutic lip products, offering both cosmetic and anti-QS properties.