WHO monographs on selected medicinal plants - travolekar.ru

<strong>WHO</strong> <strong>monographs</strong> on selected medicinal plants
The effect of the fruit on the expression of P-fimbriae of E. coli was assessed
by growing P-fimbriated E. coli in solid media containing cranberry
juice. Cranberry concentrate at pH 7.0 was added to the medium to achieve
a final concentration of 25%. E. coli strains JR1 and DS17 were plated on
to this medium, with a plain medium control, and incubated at 37 °C. Cultures
were tested for ability to agglutinate P-receptor-specific beads. The
results demonstrated that for E. coli strain JR1, P-fimbrial agglutination
was inhibited after the third plating and strain DS17 was fully inhibited
after the second plating. Fully inhibited bacteria had a 100% reduction in
expression of fimbriae (25). Two compounds in cranberry juice inhibited
lectin-mediated adherence of E. coli to mucosal cells. One of these compounds
was fructose and the other was a nondialysable polymeric compound
(25). Further investigations have found that exposure of pathogenic
bacteria to the nondialysable polymeric compound in either the gut or
bladder produces a bacteriostatic effect by inhibiting the expression of
specific adhesins present on the pili on the bacterial surface (26, 28).
The proanthocyanidin fraction, isolated from an ethyl acetate extract
of the fruit, was assessed for its ability to prevent adherence of E. coli by
measuring the ability to prevent agglutination of both isolated P-receptor
resin-coated beads and human erythrocytes. The proanthocyanidin fraction,
at a concentration as low as 75.0 mg/ml, exhibited potent antiadherence
activity in uropathogenic isolates of P-fimbriated E. coli bacteria to
cellular surfaces containing alpha-Gal(14)beta-Gal receptor sequences
similar to those on epithelial cells in the urinary tract. The chemical structures
of the proanthocyanidins consisted predominantly of epicatechin
units containing at least one A-type linkage. The procyanidin A2 was the
most common terminating unit, occurring about four times as frequently
as the epicatechin monomer (29). Isolated A-type proanthocyanidins isolated
from cranberry juice cocktail had anti-adhesive activity at 60 g/ml,
while the B-type exhibited weak activity at 1.2 mg/ml (30).
A high-molecular-weight constituent of the fruit, named nondialysable
material, at concentrations of 100.0 μg/ml, inhibited the adhesion of
Helicobacter pylori strain BZMC-25 to human gastric mucosal cells. The
inhibition of adhesion by nondialysable material was dose-dependent,
and the 50% inhibitory concentration was strain-dependent, the concentrations
being 37.0, 125.0 and 305.0 μg/ml for H. pylori strains BZMC-25,
EHL-65 and 17874, respectively (31).
In one study, uropathogenic P-fimbriated E. coli isolates were obtained
from the urine of women with clinically diagnosed, culture-confirmed
urinary tract infections and incubated for 20 minutes in urine collected
over a 12-hour period from healthy women before and after consumption
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