Cuminum cyminum L. Essential Oil: A Promising Antibacterial and Antivirulence Agent Against Multidrug-Resistant Staphylococcus aureus

Abstract

Cuminum cyminum L. (cumin) is valued for its aromatic and medicinal properties. There are several reports of antibacterial activity of C. cyminum essential oil (CcEO). Accordingly, the present study was conducted to investigate the mechanism(s) of action of the CcEO against multidrug-resistant (MDR) Staphylococcus aureus. Therefore, 10 S. aureus MDR isolates, obtained from different sources, were selected based on the antibiotic susceptibility patterns and the Clinical and Laboratory Standards Institute definition and subjected to the examinations. Our results exhibited promising bacteriostatic and bactericidal properties of the CcEO. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration values ranged from 5 to 10 and 10 to 20 μL ⋅ mL–1, respectively. Scanning electron microscope was used to assess the bacterial cell structure and morphology after the induction with 1/2 MIC concentration of the CcEO. The observed morphological changes appeared to be deformation of the cell membrane and destruction of the cells. In the case of quorum sensing inhibitory potential, treatment of S. aureus isolates with the sub-MIC concentrations (1/2 MIC) of the CcEO significantly reduced the hld expression (3.13-fold downregulation), which considerably controls S. aureus quorum-sensing accessory regulator system. Another virulence factor influenced by the CcEO was the polysaccharide intercellular adhesion production system, as an important component of cell–cell adhesion and biofilm formation. Consequently, the expression level of the intercellular adhesion (ica) locus in the S. aureus cells was examined following treatment with CcEO. The results showed significant decrease (−3.3-fold) in ica expression, indicating that the CcEO could potentially interfere with the process of biofilm formation. Using the ethidium bromide efflux inhibition assay, the S. aureus NorA efflux pump was phenotypically but not genotypically (in quantitative polymerase chain reaction assay) affected by the CcEO treatment. Using gas chromatography–mass spectrometry analysis, cuminic aldehyde (38.26%), α,β-dihydroxyethylbenzene (29.16%), 2-caren-10-al (11.20%), and γ-terpinene (6.49%) were the most detected compounds. The antibacterial and antivirulence action of the CcEO at sub-MIC concentrations means that no microbial resistance will be promoted and developed after the treatment with this agent. These findings revealed that the CcEO is a promising antibacterial agent to control infections caused by the MDR S. aureus strains.

Bisdemethoxycurcumin Reduces Methicillin-Resistant Staphylococcus aureus Expression of Virulence-Related Exoproteins and Inhibits the Biofilm Formation

“…The inhibition of the BDMC on the biofilm formation of S. aureus DPS-1, DPS-2, and ATCC 33591 was established in a crystal violet biofilm assay using a previously described protocol [36]. To each well of 96-well microtiter plates, 100 µL of overnight culture (0.5 MacFarland bacterial culture) was added and treated with sub-concentrations of BDMC.…”

Chemical Composition of Kickxia aegyptiaca Essential Oil and Its Potential Antioxidant and Antimicrobial Activities

“…This variation could be ascribed to the genetic differences in both species [ 24 ], and the environmental and climatic conditions have also been reported to affect the composition of the EO [ 23 , 25 , 26 , 27 ]. Cuminic aldehyde is basically the main compound of Cuminum cyminum, with a concentration of 22.4–41.5% [ 28 , 29 , 30 ]. On the other hand, p -cymen-7-ol was described as a major compound in the EOs of several plants, for instance, Curcuma cf.…”

“…A similar study by de Sousa, et al [ 50 ] indicated that the combination of carvacrol and 1,8-cineole maximizes the inhibitory activity against bacterial strains associated with vegetable processing. In addition, cuminic aldehyde has been reported to have antibacterial effects [ 29 , 30 ]. In contrast to our results, the EO of C. cyminum , rich with cuminic aldehyde, did not show antibacterial activity against Pseudomonas species [ 29 ].…”

1,8-Cineole inhibits biofilm formation and bacterial pathogenicity by suppressing luxS gene expression in Escherichia coli

“…Quorum-sensing-mediated inter-bacterial communication has been recognized as an important signaling communication mode in bacterial flora ( Mukherjee and Bassler 2019b ). Numerous studies have shown that bicyclic terpenoids have significant antibacterial and anti-biofilm activities ( Sharifi, Mohammadzadeh et al, 2021 ). 1,8-cineole is the active ingredient in the essential oil extracted from most camphoraceous plants.…”