Acta Pharm. 2014 Jun;64(2):173-86. doi: 10.2478/acph-2014-0019.
Abstract
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.
