Efficacy of cinnamon bark oil and cinnamaldehyde on anti-multidrug resistant Pseudomonas aeruginosa and the synergistic effects in combination with other antimicrobial agents

Abstract

BackgroundThe emergence of drug resistant pathogens becomes a crucial problem for infectious diseases worldwide. Among these bacteria, Pseudomonas aeruginosa is one of which highly resists to many currently used drugs and becomes a major concern in public health. Up till now, the search for potential antimicrobial agents has been still a challenge for researchers.MethodsBroth microdilution assay was used to determine minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the essential oils and antibiotics against P. aeruginosa. Inhibition activity of the essential oils under vapor condition was examined to obtain the minimum inhibitory dose (MID). Time-kill assay included in this study was performed according to CLSI guideline. Bioautographic assay was used to detect active components of the essential oil. Synergistic effect with currently used antibiotics was further examined by checkerboard assay.Results and DiscussionIn this study, a variety of essential oils were examined for anti-multidrug resistant P. aeruginosa (MDR-PA) activity, of which cinnamon bark oil showed the strongest antimicrobial activity against all clinical-isolated MDR-PA strains with MIC of 0.0562–0.225 % v/v and MBC of 0.1125–1.8 % v/v. Bioautographic results demonstrated that the active compounds of cinnamon bark oil were cinnamaldehyde and eugenol which showed strong inhibitory effect against P. aeruginosa. Interestingly, cinnamaldehyde, a major constituent of cinnamon bark oil, possessed stronger antimicrobial effect to P. aeruginosa than eugenol. Under gaseous condition, cinnamon bark oil and cinnamaldehyde showed antibacterial activity against MDR-PA strains with MID of 0.5–1 mg/L. Moreover, combination of cinnamon bark oil or cinnamaldehyde with currently used antibiotics was further studied by checkerboard assay to examine synergistic interactions on clinically isolated MDR-PA strains. Cinnamon bark oil and cinnamaldehyde combined with colistin demonstrated synergistic rates at 16.7 and 10 %, respectively.ConclusionThese results indicated that cinnamon bark oil and cinnamaldehyde might be active natural compounds which could be further examined as alternative treatment for multidrug-resistant P. aeruginosa infection.

Cinnamaldehyde Inhibits Staphylococcus aureus Virulence Factors and Protects against Infection in a Galleria mellonella Model

“…Cinnamaldehyde is the predominant active compound found in the cinnamon oil from the stem bark of Cinnamomum cassia . It is well-known for its wide spectrum antimicrobial activity at concentrations higher than 500 mg/ml (Chen et al, 2015; Shen et al, 2015; Utchariyakiat et al, 2016). The antimicrobial actions of cinnamaldehyde are related to inhibition of cell division through FtsZ (filamentation temperature sensitive protein Z; Domadia et al, 2007), reduction of energy generation and glucose uptake or expenditure (Gill and Holley, 2004) and effects on bacterial cell membrane permeability and integrity (Gill and Holley, 2004; Shen et al, 2015).…”

Antimicrobial effects of cinnamon essential oil and cinnamaldehyde combined with EDTA against canine otitis externa pathogens

“…aeruginosa , whereas cinnamon oil took around 4 h. Our studies are consistent with a previous study reporting that cinnamaldehyde took a shorter time to inhibit MDRPA growth at their MIC (0·1125–0·225%) compared to cinnamon bark oil, indicating the strong antimicrobial activity (Utchariyakiat et al . ). For Staph.…”

“…Cinnamaldehyde, the most abundant components of the cinnamon essential oil, either used alone or in combination exhibited potent antibacterial and antifungal activities (Utchariyakiat et al . ; Friedman ; Firmino et al . ; Garcia‐Salinas et al .…”

Study Effect Type of Extraction Method And Type of Solvent To Cinnamaldehyde and Trans-Cinnamic Acid Dry Extract Cinnamon (Cinnamomum burmanii [Nees & T, Nees]Blume)

“…1,2 Cinnamaldehyde have antibacterial activity. 3,4 The odourant molecule trans-cinnamaldehyde is the mayor of component of cinnamon oil and it responsible for its characteristic smell. 5 Cinnamic acid is a significantly important fuctional group as an effective insuling releasing agent.…”