Abstract
LC-MS characterized cranberry extract from the fruits of Vaccinium macrocarpon inhibited
under in vitro conditions the bacterial adhesion of Escherichia coli strain 2980 uropathogenic E. coli (UPEC strains UTI89, NU14) to T24 bladder cells and adhesion of UPEC strain CFT073
to A498 kidney cells in a concentration-dependent manner. Within a biomedical study,
urine samples from 16 volunteers (8 male, 8 female) consuming cranberry extract for
7 d (900 mg/d) were analyzed for potential antiadhesive activity against UPEC by ex
vivo experiments. Results indicated inhibition of adhesion of UPEC strain UTI89 to
human T24 bladder cells. Subgroup analysis proved significant inhibition of bacterial
adhesion in case of urine samples obtained from male volunteers while female urine
did not influence the bacterial attachment. Differences between antiadhesive capacity
of urine samples from male/female volunteers were significant. Protein analysis of
the urine samples indicated increased amounts of Tamm-Horsfall protein (THP, syn.
uromodulin) in the active samples. Inhibition of bacterial adhesion by the urine samples
was correlated to the respective amount of THP. As it is known that THP, a highly
mannosylated glycoprotein, strongly interacts with FimH of UPEC, this will lead to
a decreased interaction with uroplakin, a FimH-binding transmembrane protein of urothelial
lining cells. From these data it can be concluded that the antiadhesive effect of
cranberry after oral intake is not only related to the direct inhibition of bacterial
adhesins by extract compounds but is additionally due to an induction of antiadhesive
THP in the kidney.
Key words
adhesion - cranberry -
Vaccinium macrocarpon
- Ericaceae - Tamm-Horsfall protein - uropathogenic
E. coli
