Antibacterial and quorum sensing regulatory activities of some traditional Eastern-European medicinal plants

Abstract

The increasing resistance of human and animal bacterial pathogens to a wide spectrum of antibiotics has become an emerging problem in the 21st century (1). In view of the slow progress in the development of antibiotic classes that can overcome drug-resistance mechanisms, the next generation of safe and effective antimicrobial drugs is likely to be The objective of this study was to screen extracts of twenty Eastern European medicinal plants, using wild-type and reporter Chromobacterium violaceum bioassays, for novel components that target bacterial cells and their quorum sensing (QS) communication systems. Three types of activity and their combinations were revealed: (i) direct antimicrobial growth-inhibitory activity, (ii) non-specific and specific pro-QS activities, (iii) anti-QS activity. Among seven plant extracts showing direct growth-inhibitory activity, the strongest effect was shown by Arctostaphylos uva--ursi (bearberry) leaves. Many plants stimulated violacein production by wild-type C. violaceum ATCC 31532 in a non-specific manner, and only the herb Bidens tripartita (three-lobe beggarticks) contained compounds that mimic acyl-homoserine lactone and operated as a QS agonist. Anti-QS activity was found in eleven plants including Quercus robur (oak) cortex, Betula verrucosa (birch) buds and Eucalyptus viminalis (Manna Gum) leaves. Subsequent statistical analysis showed differences between antimicrobial and anti-QS activities, whereas both activities were defined by phylogenetic position of medical resource plant. Finally, extract from Quercus robur cortex revealed at least two fractions, showing different anti-QS mechanisms. These data confirm that multicomponent anti-infectious mechanisms are used by plants, which may be useful for drug development.

The use of medicinal plants by rural populations of the Pastaza province in the Ecuadorian Amazon

“…A.H. Gentry were the most frequently reported species, as showing in Table 4. (Tolmacheva et al 2014), heart diseases, laxative (Costa et al 2012).…”

Total Phenol Content and Antimicrobial Activity of Lingonberry (Vaccinium vitis-idaea L.) from Several Areas in the Eastern Carpathians

“…piscicida and Lactococcus garvieae (Bulfon et al, 2014). Tolmacheva et al (2014) applied aqueous and ethanolic extracts from Vaccinium vitis idaea in a radial growth inhibition assay against wild-type Chromobacterium violaceum ATCC 31532 and reporter Chromobacterium violaceum NCTC 13274 strains observed a prominent growth-inhibition activity.…”

Mixtures of Biologically Active Substances of Oak Bark Extracts Change Immunological and Productive Indicators of Broilers

“…One of obstacles for use of phytogenic compounds is instable chemical composition of plant extracts depending on growing conditions, ecosystem, and other factors. Earlier, several compounds from oak bark extract (Quercus cortex) having both antibacterial and anti-QS activity [12,13] was found. These substances were used in tests on agricultural poultry.…”

“…In tests we used mixture of substances earlier extracted from the oak bark [12,13] and artificially synthesized (Acros Organics B.V.B.A., Belgium). These are 2-n-propylresorcinol (98 %), 4-hydroxi-3-metoxibenzaldehyde (99 %), 7-hydroxi coumarine (99 %), 3,4,5-trimetoxiphenol (98.5 %), scopoletin (95 %), and coniferyl alcohol (98 %).…”