Flavanones, flavonoids abundant in
Citrus, have been shown to inte
rfe
re with quo
rum sensing (QS) and affect
related physiological p
rocesses. We have investigated the QS-inhibito
ry effects of an o
range ext
ract en
riched in
O-glycosylated flavanones (mainly na
ringin, neohespe
ridin, and hespe
ridin). The QS-inhibito
ry capacity of this ext
ract and its main flavanone components was fi
rst sc
reened using the bacte
riological monito
ring system
Chromobacterium violaceum. We next examined the ability of the o
range ext
ract and of some of the flavanones to (i)
reduce the levels of the QS mediato
rs p
roduced by
Y. enterocolitica using HPLC-MS/MS, (ii) inhibit biofilm fo
rmation, and (iii) inhibit swimming and swa
rming motility. Additionally, we evaluated changes in the exp
ression of specific genes involved in the synthesis of the lactones (
yenI,
yenR) and in the flagella
r regulon (
flhDC,
fleB,
fliA) by RT-PCR. The
results showed that the o
range ext
ract and its main flavanone components inhibited QS in
C. violaceum, diminished the levels of lactones sec
reted by
Y. enterocolitica to the media, and dec
reased QS-associated biofilm matu
ration without affecting bacte
rial g
rowth. Among the tested compounds, na
ringin was found to inhibit swimming motility. Exposu
re to the o
range ext
ract and (o
r) to na
ringin was also found to be associated with induction of the t
ransc
ription levels of
yenR,
flhDC, and
fliA. This wo
rk shows the in vit
ro QS-inhibito
ry effects of an o
range ext
ract en
riched in flavanones against a human ente
ropathogen at doses that can be achieved th
rough the diet and suggests that consumption of these natu
ral ext
racts may have a beneficial antipathogenic effect.
r>Keywords:
rs" href="http://pubs.acs.org/action/doSearch?action=search&searchText=cell%E2%88%92cell+communication&qsSearchArea=searchText">cell鈭抍ell communication; rs" href="http://pubs.acs.org/action/doSearch?action=search&searchText=Citrus+polyphenols&qsSearchArea=searchText">Citrus polyphenols; rs" href="http://pubs.acs.org/action/doSearch?action=search&searchText=flavonoids+anti%5C-QS+activity&qsSearchArea=searchText">flavonoids anti-QS activity; rs" href="http://pubs.acs.org/action/doSearch?action=search&searchText=quorum+quenching&qsSearchArea=searchText">quorum quenching; rs" href="http://pubs.acs.org/action/doSearch?action=search&searchText=LC%5C-MS%2FMS+spectrometry&qsSearchArea=searchText">LC-MS/MS spectrometry; rs" href="http://pubs.acs.org/action/doSearch?action=search&searchText=swimming&qsSearchArea=searchText">swimming; rs" href="http://pubs.acs.org/action/doSearch?action=search&searchText=swarming&qsSearchArea=searchText">swarming; rs" href="http://pubs.acs.org/action/doSearch?action=search&searchText=pathogenic+bacteria&qsSearchArea=searchText">pathogenic bacteria; rs" href="http://pubs.acs.org/action/doSearch?action=search&searchText=gene+expression&qsSearchArea=searchText">gene expression