No abstract - Introduction: It is well “known” by the general lay public that cranberry juice is helpful in treating and preventing urinary tract infections (UTIs). However, the evidence for this assumption has never been critically reviewed in urologic reports or elsewhere. The evidence for the two proposed mechanisms of action of cranberry juice, urinary acidification and inhibition of bacterial adherence, are critically analyzed.

OBJECTIVE: This study compares the effects of daily cranberry juice to those of Lactobacillus in children with recurrent urinary tract infections (UTIs).

MATERIAL AND METHODS: Eighty-four girls aged between 3 and 14 years were randomized to cranberry, Lactobacillus or control in three treatment arms: G1, cranberry juice 50 ml daily (n=28); G2, 100 ml of Lactobacillus GG drink on 5 days a month (n=27); and G3, controls (n=29). The study lasted for 6 months.

RESULTS: Only four subjects withdrew: 1/28 (3.5%) from G1, 1/27 (3.7%) from G2 and 2/29 (6.8%) from G3, because of poor compliance to the established protocol. There were 34 episodes of UTIs in this cohort: 5/27 (18.5%) in G1, 11/26 (42.3%) in G2 and 18/27 (48.1%) in the G3, with at least one episode of infection (p0.05).

CONCLUSION: These data suggest that daily consumption of concentrated cranberry juice can significantly prevent the recurrence of symptomatic UTIs in children.

PURPOSE: Cranberry proanthocyanidins have been identified as possible inhibitors of Escherichia coli adherence to uroepithelial cells. However, little is known about the dose range of this effect. Furthermore, it has not been studied directly in the urogenital system. To address these issues we tested the effect of a cranberry powder and proanthocyanidin extract on adherence of a P-fimbriated uropathogenic E. coli isolate to 2 new urogenital model systems, namely primary cultured bladder epithelial cells and vaginal epithelial cells.

MATERIALS AND METHODS: E. coli IA2 was pre-incubated with a commercially available cranberry powder (9 mg proanthocyanidin per gm) or with increasing concentrations of proanthocyanidin extract. Adherence of E. coli IA2 to primary cultured bladder epithelial cells or vaginal epithelial cells was measured before and after exposure to these products.

RESULTS: Cranberry powder decreased mean adherence of E. coli IA2 to vaginal epithelial cells from 18.6 to 1.8 bacteria per cell (p 0.001). Mean adherence of E. coli to primary cultured bladder epithelial cells was decreased by exposure to 50 mug/ml proanthocyanidin extract from 6.9 to 1.6 bacteria per cell (p 0.001). Inhibition of adherence of E. coli by proanthocyanidin extract occurred in linear, dose dependent fashion over a proanthocyanidin concentration range of 75 to 5 mug/ml.

CONCLUSIONS: Cranberry products can inhibit E. coli adherence to biologically relevant model systems of primary cultured bladder and vaginal epithelial cells. This effect occurs in a dose dependent relationship. These findings provide further mechanistic evidence and biological plausibility for the role of cranberry products for preventing urinary tract infection.

PURPOSE: We compared the effects of daily cranberry juice cocktail to those of placebo during pregnancy on asymptomatic bacteriuria and symptomatic urinary tract infections.MATERIALS AND METHODS: A total of 188 women were randomized to cranberry or placebo in 3 treatment arms of A-cranberry 3 times daily (58), B-cranberry at breakfast then placebo at lunch and dinner (67), and C-placebo 3 times daily (63). After 27.7% (52 of 188) of the subjects were enrolled in the study the dosing regimens were changed to twice daily dosing to improve compliance.RESULTS: There were 27 urinary tract infections in 18 subjects in this cohort, with 6 in 4 group A subjects, 10 in 7 group B subjects and 11 in 7 group C subjects (p = 0.71). There was a 57% and 41% reduction in the frequency of asymptomatic bacteriuria and all urinary tract infections, respectively, in the multiple daily dosing group. However, this study was not sufficiently powered at the alpha 0.05 level (CI 0.14-1.39 and 0.22-1.60, respectively, incidence rate ratios). Of 188 subjects 73 (38.8%) withdrew, most for gastrointestinal upset.CONCLUSIONS: These data suggest there may be a protective effect of cranberry ingestion against asymptomatic bacteriuria and symptomatic urinary tract infections in pregnancy. Further studies are planned to evaluate this effect.

OBJECTIVE: To test the recommendation that to avoid the complications of long-term indwelling bladder catheterization (e.g. encrustation and blockage by crystalline Proteus mirabilis biofilms) patients should drink cranberry juice.

MATERIALS AND METHODS: Urine was collected from groups of volunteers who had drunk up to 2 x 500 mL of cranberry juice or water within an 8-h period. Laboratory models of the catheterized bladder were supplied with urine from these groups and inoculated with P. mirabilis. After incubation for 24 or 48 h, the extent of catheter encrustation was determined by chemical analysis for calcium and magnesium. Encrustation was also visualized by scanning electron microscopy.

RESULTS: The amounts of calcium and magnesium recovered from catheters incubated in urine pooled from individuals who had drunk 500 mL of cranberry juice was not significantly different from that on catheters incubated in pooled urine from control subjects who had drunk 500 mL of water. However, there was significantly less encrustation (P = 0.007) on catheters from models receiving urine from volunteers who had drunk 2 x 500 mL of water than on catheters incubated in models supplied with urine from volunteers who had drunk 2 x 500 mL of cranberry juice. The amounts of encrustation on these two groups of catheters were also significantly less than that on catheters incubated in models supplied with urine from volunteers who had not supplemented their normal fluid intake. (P 0.001). Experiments in the models using artificial urine showed that increasing the low fluid intake (720 mL/24 h) characteristic of many patients undergoing long-term catheterization by factors of three and six, significantly (P 0.01) reduced the amounts of calcium and magnesium that formed on catheters. At a simulated fluid intake of 720 mL/24 h, catheters blocked with encrustation after a mean of 42.5 h, while those supplied with urine produced from an intake of 4320 mL/24 h, drained freely for > 10 days.

CONCLUSION: In this in vitro study, drinking cranberry juice did not produce urine that was inhibitory to the development of crystalline catheter-blocking P. mirabilis biofilms. The important factor in preventing catheter encrustation is a high fluid intake.

INTRODUCTION/OBJECTIVE: Cranberries have been shown to produce urinary metabolites that influence uropathogen adhesion and prevent urinary tract infections. This study was designed to determine if consuming reconstituted, unsweetened cranberry drink from extract retained its bioactive properties by reducing uropathogen adhesion without adversely affecting urinary calcium, magnesium and the vaginal microflora. MATERIALS AND METHODS: A randomized crossover study was undertaken in 12 healthy women consuming reconstituted unsweetened cranberry drink, CranActin or water. The urine was collected at 4 hours and 1 week of consumption and evaluated for antiadhesive properties and urinary pH, calcium and magnesium. Vaginal swabs were collected after 1 week of treatment to assess the vaginal microbiota by DGGE. RESULTS: The resultant urine produced by subjects who consumed 500 ml reconstituted cranberry extract twice per day, significantly reduced the adherence to epithelial cells of P-fimbriated uropathogenic Escherichia coli and showed a tendency towards significance for two E. coli strains expressing fimbriae and an Enterococcus faecalis isolate. The cranberry drink treatment did not alter urinary pH, but reduced calcium and magnesium concentrations compared to water, although not to statistical significance. The reconstituted cranberry drink had no apparent detrimental effect on the vaginal microbiota. However, consuming twice daily resulted in an apparent loss of a potential pathogen from the vagina in 42% subjects. CONCLUSIONS: The present findings suggest that reconstituted cranberry drink may retain the ability to reduce the risk of UTI by inhibiting pathogen adhesion while not detrimentally affecting urinary pH or vaginal microbiota, or the risk of calculi

Cranberry constituents are known to exert anti-adhesion activity on H. pylori in vitro. To determine their possible additive effect to triple therapy with omeprazole, amoxicillin and clarithromycin (OAC), a double-blind randomized clinical study was carried out. One-hundred-seventy-seven patients with H. pylori infection treated with OAC for 1 week were randomly allocated to receive 250 mL of either cranberry juice (cranberry-OAC, n = 89) or placebo beverage (placebo-OAC, n = 88) twice daily and only cranberry juice or placebo beverage for the next 2 weeks. Treatment outcome was determined with the(13)C urea breath test ((13)C-UBT). An additional control group consisted of patients referred to the same center during the same period who were treated with OAC alone for 1 week (non-placebo-OAC, n = 712). Overall, the rate of H. pylori eradication ((13)C-UBT 3.5) was 82.5%, with no statistically significant difference among the three arms. Analysis by gender revealed that for female subjects, the eradication rate was higher in the cranberry-OAC arm (n = 42, 95.2%) than in the placebo-OAC arm (n = 53, 86.8%) and significantly higher than in the non-placebo-OAC group (n = 425, 80%; p = 0.03). For males, the rate was nonsignificantly lower in the cranberry-OAC arm (n = 35, 73.9%) than in the placebo-OAC arm (n = 45, 80.0%) and non-placebo-OAC group (n = 287, 85.0%). These results suggest that the addition of cranberry to triple therapy improves the rate of H. pylori eradication in females.

An experimental study was conducted on 3 consecutive 12-hour days to determine if selected physical properties of feeding tubes (material and diameter) affect tube clogging. Effectiveness of three irrigant fluids (cranberry juice, Coca-Cola, and water) in preventing tube clogging was studied. One hundred eight tubes were connected to gravity flow feeding bags containing isotonic enteral formula; 54 polyurethane and 54 silicone tubes were equally divided as to external diameters of 8 French (Fr), 10 Fr, and 12 Fr. At 4-hour intervals, flow regulators on the feeding bags were adjusted to a rate of 50 ml/hour. Fluid volumes delivered per minute were measured for each tube at 2-hour intervals. One set of tubes at each station was irrigated periodically with cranberry juice, Coca-Cola, or water. On each of the 3 days, analyses revealed significant, p less than .05, effects for tube material, cranberry juice contrasted with Coca-Cola and water as irrigants, and time. Polyurethane was consistently superior to silicone as a tube material, and cranberry juice was consistently inferior to both Coca-Cola and water as an irrigant. Tube diameter had no significant effect on the incidence of tube clogging.

No abstract

"AIMS: To investigate the influence of several phenolic compounds isolated from cranberry fruit (Vaccinium macrocarpon) on some of the virulence properties of Streptococcus mutans associated with glucan synthesis and acidogenicity.

METHODS AND RESULTS: Individual phenolic acids, flavonols and proanthocyanidins were isolated by semi-preparative high-performance liquid chromatography from fresh cranberry fruit. Flavonols and proanthocyanidins (at 500 micromol l(-1)) moderately inhibited the activity of surface-adsorbed glucosyltransferases (GTFs) B and C and F-ATPases (15-35% inhibition; P 0.05), and also disrupted acid production by S. mutans cells without affecting bacterial viability. Phenolic acids displayed minimal biological effects. Quercetin-3-arabinofuranoside, myricetin and procyanidin A2 displayed the most inhibition of S. mutans virulence traits; a combination of these compounds displayed enhanced effects.

CONCLUSIONS: Specific flavonoids from cranberries exhibit statistically significant but moderate biological activity against S. mutans. The biological activity of cranberry extracts may be a result from the complex mixture of flavonoids rather than a single active compound.

SIGNIFICANCE AND IMPACT OF STUDY: This is the first study to identify the bioactive constituents in cranberry against an oral bacterium using highly purified isolated compounds. The combined effects of specific flavonols and proanthocyanidins from cranberry on GTFs activity, acid production and acid tolerance of S. mutans make them attractive compounds to fully explore for their anti-biofilm and cariostatic properties."