Background: Quorum sensing is the key regulator of virulence factors of
Pseudomonas aeruginosa
such as biofilm formation,
motility, productions of proteases, hemolysin, pyocyanin, and toxins. The aim of this study was to explore the effect of the extracts
from some medicinal plants on quorum sensing and related virulence factors of P. aeruginosa.
Material and Methods: Quorum sensing inhibitory (OSI) effect of the alcohol extracts of 20 medicinal plants was evaluated by
Chromobacterium violaceum reporter using agar cup diffusion method. The efficient QSI extracts were tested for their activity
against biofilm synthesis, motility, and synthesis of pyocyanin from P. aeruginosa PA14
Results: The extracts of
Citrus sinensis
,
Laurus nobilis
,
Elettaria cardamomum
,
Allium cepa
, and
Coriandrum sativum
exhibited
potent quorum quenching effect. On the other hand,
Psidium guajava
and
Mentha longifolia
extracts showed lower QSI activity.
These extracts exhibited significant elimination of pyocyanin formation and biofilm development of
Pseudomonas aeruginosa
PA14. In addition, they significantly inhibited twitching and swimming motilities of
P. aeruginosa PA14.
Conclusion: This study illustrated, for the first time, the importance of
C. sinensis,
L. nobilis,
E. cardamomum,
A. cepa, and
C.
sativum as quorum sensing inhibitors and virulence suppressors of
P. aeruginosa. Thus, these plants could provide a natural source
for the elimination of
Pseudomonas pathogenesis
.
