Cuminaldehyde inhibits biofilm formation by affecting the primary adhesion of Staphylococcus aureus

In Iranian, ethnopharmacological studies show that Cuminum cyminum is commonly used in pain relief. The most abundant component in C. cyminum seeds is cuminaldehyde (CUM). However, there are few articles that have evaluated the anti-biofilm activity against Staphylococcus aureus (S. aureus). The nobility of this study was to evaluate the anti-biofilm effect of CUM and to investigate its possible mechanism of action. Crystal violet staining assay showed that CUM decreased biofilm biomass. The morphological observation indicated that CUM restrained the adhesion of biofilm, and destroyed the integrated and cohesive structure of biofilm. MTT assay proved that the metabolic activity of adherent cells treated with CUM was reduced. In vitro assays exhibited that cell motility, cell surface hydrophobicity, and extracellular polymers production of S. aureus were also inhibited in the presence of CUM. Furthermore, quantitative real-time PCR analysis confirmed the ability of CUM to interfere with the expression of adhesion genes associated with biofilm formation such as agrA, icaA, sigB, ebpS, fnbA, fib and clfA. Molecular docking speculated that the interaction of CUM with SarA could inhibit SarA-DNA binding, and ultimately inhibit the formation of biofilm. The results of this trial provided scientific experimental data for the use of CUM as an anti-biofilm agent.