Evaluating the antimicrobial potential of green cardamom essential oil focusing on quorum sensing inhibition of Chromobacterium violaceum

Gan

Comp Rev Food Sci Food Safe

et al. 2020

In recent decades, reduced antimicrobial effectiveness, increased bacterial infection, and newly emerged microbial resistance have become global public issues, leading to an urgent need to find effective strategies to counteract these problems. Strategies targeting bacterial virulence factors rather than bacterial survival have attracted increasing interest, since the modulation of virulence factors may prevent the development of drug resistance in bacteria. Spices are promising natural sources of antivirulence compounds owing to their wide availability, diverse antivirulence phytochemical constituents, and generally favorable safety profiles. Essential oils are the predominant and most important antivirulence components of spices. This review addresses the recent efforts of using spice essential oils to inhibit main bacterial virulence traits, including the quorum sensing system, biofilm formation, motility, and toxin production, with an intensive discussion of related mechanisms. We hope that this review can provide a better understanding of the antivirulence properties of spice essential oils, which have the potential to be used as antibiotic alternatives by targeting bacterial virulence. K E Y W O R D Sbiofilm, mechanisms, motility, quorum sensing, spice essential oils, toxin 1018

Section: Bacterial Toxinsmentioning

confidence: 99%

Antivirulence properties and related mechanisms of spice essential oils: A comprehensive review

Gan

Comp Rev Food Sci Food Safe

et al. 2020

“…N -hexanoyl- l -homoserine lactone (C6-HSL), which is modulated by the cviI gene, binds to the transcriptional regulator to regulate biofilm formation, swarming movement, and the secretion of virulence factors such as violacein and exopolysaccharide (EPS) [10]. It was previously found that sub-minimal inhibitory concentration (sub-MIC) EO levels of green cardamom, rose, clove, and chamomile are capable of blocking the network in C. violaceum [11,12]. In this light, plant EOs are expected to be emerging QSIs to attenuate the virulence of pathogens and control bacterial infections and drug resistance.…”

Section: Introductionmentioning

confidence: 99%

Antibacterial Activity and Anti-Quorum Sensing Mediated Phenotype in Response to Essential Oil from Melaleuca bracteata Leaves

Wang

Huang

Yang

et al. 2019

IJMS

The prominent antibacterial and quorum sensing (QS) inhibition activity of aromatic plants can be used as a novel intervention strategy for attenuating bacterial pathogenicity. In the present work, a total of 29 chemical components were identified in the essential oil (EO) of Melaleuca bracteata leaves by gas chromatography-mass spectrometry (GC-MS). The principal component was methyleugenol, followed by methyl trans-cinnamate, with relative contents of 90.46% and 4.25%, respectively. Meanwhile, the antibacterial activity and the QS inhibitory activity of M. bracteata EO were first evaluated here. Antibacterial activity assay and MIC detection against seven pathogens (Dickeya dadantii Onc5, Staphylococcus aureus ATCC25933, Pseudomonas spp., Escherichia coli ATCC25922, Serratia marcescens MG1, Pseudomonas aeruginosa PAO1 and Chromobacterium violaceum ATCC31532) demonstrated that S. aureus ATCC25933 and S. marcescens MG1 had the higher sensitivity to M. bracteata EO, while P. aeruginosa PAO1 displayed the strongest resistance to M. bracteata EO. An anti-QS (anti-quorum sensing) assay revealed that at sub-minimal inhibitory concentrations (sub-MICs), M. bracteata EO strongly interfered with the phenotype, including violacein production, biofilm biomass, and swarming motility, as well as N-hexanoyl-L-homoserine lactone (C6-HSL) production (i.e., a signaling molecule in C. violaceum ATCC31532) of C. violaceum. Detection of C6-HSL indicated that M. bracteata EO was capable of not only inhibiting C6-HSL production in C. violaceum, but also degrading the C6-HSL. Importantly, changes of exogenous C6-HSL production in C. violaceum CV026 revealed a possible interaction between M. bracteata EO and a regulatory protein (cviR). Additionally, quantitative real-time polymerase chain reaction (RT-qPCR) analysis demonstrated that the expression of QS-related genes (cviI, cviR, vioABCDE, hmsNR, lasA-B, pilE1, pilE3, and hcnB) was significantly suppressed. Conclusively, these results indicated that M. bracteata EO can act as a potential antibacterial agent and QS inhibitor (QSI) against pathogens, preventing and controlling bacterial contamination.

“…Plants produce numerous secondary metabolites with antimicrobial properties as part of their normal growth process with the purpose to inhibit the attack of environmental pathogens; therefore, plant extracts are usually revealed with effective antibacterial properties. Previous studies have identified antibacterial and antifungal effects for: (i) black currant ( E. coli , A. niger, P. vulgaris, C. albicans —[ 64 ]); (ii) clove and thyme ( S. aureus, P. aeruginosa, E. coli, S. pyogenes, Corynebacterium spp, Salmonella spp, B. fragilis, C. albicans —[ 65 ]); (iii) blueberry ( L. monocytogenes, S. enteritidis —[ 66 ]); (iv) hibiscus ( S. typhimurium, S. aureus —[ 67 ]); (v) green tea ( S. mutans , dental bacteria—[ 68 ]); (vi) cardamom ( C. albicans, S. mutans, S. aureus, L. monocytogenes, B. cereus, S. typhimurium —[ 69 ]); (vii) alfalfa ( S. pneumonia, H. influenza, M. catarrhalis —[ 70 ]); (viii) sage ( S. mutans, S. aureus, E. coli —[ 71 ]); (ix) Echinacea ( Burkholderia cepacia complex bacteria—[ 72 ]). One mechanism through which plant extracts exhibit antimicrobial properties is the synergism between phytochemical compounds or between phytochemicals and associated antibiotics [ 73 ]; the synergistic mechanism can be explained by the association of numerous different molecules in plant extracts so that bacterial resistance through genetic mutations triggered by external stimuli is more difficult to develop [ 74 ].…”

Section: Resultsmentioning

confidence: 99%

Nutritional, Antioxidant, Antimicrobial, and Toxicological Profile of Two Innovative Types of Vegan, Sugar-Free Chocolate

Dumbrava

Popescu

Şoica

et al. 2020

Foods

Increased sugar consumption and unhealthy dietary patterns are key drivers of many preventable diseases that result in disability and death worldwide. However, health awareness has increased over the past decades creating a massive on-going demand for new low/non-caloric natural sweeteners that have a high potential and are safer for consumption than artificial ones. The current study aims to investigate the nutritional properties, in vitro toxicological profile, total/individual polyphenols content, and the antioxidant, anti-cariogenic, and antimicrobial activity of two newly obtained vegan and sugar-free chocolate (VHC1 and VHC2). The energy values for the two finished products were very similar, 408.04 kcal/100 g for VHC1 and 404.68 kcal/100 g for VHC2. Both products, VHC1 and VHC2 present strong antioxidant activities, whereas antimicrobial results show an increased activity for VHC1 compared to VHC2, because of a higher phenolic content. In vitro toxicological evaluation revealed that both samples present a safe toxicological profile, while VHC2 increased cellular turnover of dermal cell lines, highlighting its potential use in skin treatments. The current work underlines the potential use of these vegetal mixtures as sugar-free substitutes for conventional products, as nutraceuticals, as well as topic application in skin care due to antimicrobial and antioxidant effects.