An in vivo study in rats showed a cranberry juice product to inhibit the intestinal first-pass metabolism of the CYP3A substrate nifedipine. However, a clinical study involving the CYP3A probe substrate midazolam and a different cranberry juice product showed no interaction. Because the composition of bioactive components in natural products can vary substantially, a systematic in vitro-in vivo approach was taken to identify a cranberry juice capable of inhibiting enteric CYP3A in humans. First, the effects of five cranberry juices, coded A through E, were evaluated on midazolam 1'-hydroxylation activity in human intestinal microsomes. Juice E was the most potent, ablating activity at 0.5% juice (v/v) relative to control. Second, juice E was fractionated to generate hexane-, chloroform-, butanol-, and aqueous-soluble fractions. The hexane- and chloroform-soluble fractions at 50 microg/ml were the most potent, inhibiting by 77 and 63%, respectively, suggesting that the CYP3A inhibitors reside largely in these more lipophilic fractions. Finally, juice E was evaluated on the oral pharmacokinetics of midazolam in 16 healthy volunteers. Relative to water, juice E significantly increased the geometric mean area under the curve (AUC)(0-infinity) of midazolam by approximately 30% (p=0.001), decreased the geometric mean 1'-hydroxymidazolam/midazolam AUC(0-infinity) ratio by approximately 40% (p0.001), and had no effect on geometric mean terminal half-life, indicating inhibition of enteric, but not hepatic, CYP3A-mediated first-pass metabolism of midazolam. This approach both showed a potential drug interaction liability with cranberry juice and substantiated that rigorous in vitro characterization of dietary substances is required before initiation of clinical drug-diet interaction studies.

The aim of this study was to assess whether regular consumption of cranberry juice results in elevations in urinary salicylate concentrations in persons not taking salicylate drugs. Two groups of healthy female subjects (11/group) matched for age, weight, and height consumed 250 mL of either cranberry juice or a placebo solution three times a day (i.e., 750 mL/day) for 2 weeks. At weekly intervals, salicylic acid and salicyluric acid (the major urinary metabolite of salicylic acid) concentrations were determined in urine by HPLC with electrochemical detection. Concentrations of salicylic acid in plasma were also determined. Consumption of cranberry juice was associated with a marked increase (p 0.001) of salicyluric and salicylic acids in urine within 1 week of the intervention. After 2 weeks, there was also a small but significant (p 0.05) increase in salicylic acid in plasma. The regular consumption of cranberry juice results in the increased absorption of salicylic acid, an anti-inflammatory compound that may benefit health.

The objective of this study was to evaluate the effects of various berry extracts, with and without clarithromycin on Helicobacter pylori. Resistance to clarithromycin by H. pylori has been reported, leading to interest in alternatives/adjuncts to therapy with clarithromycin. H. pylori American type culture collection (ATCC) strain 49503 was grown, cell suspensions were made in
PBS and diluted 10-fold. One hundred μl of the suspension was then incubated for 18 h with extracts of raspberry, strawberry, cranberry, elderberry, blueberry, bilberry, and OptiBerry R , a blend of the six berries, at 0.25–1% concentrations. Serially diluted cell suspensions were exposed for 1 h to clarithromycin at 15 μg/ml. Ten μl of bacterial samples from the 10–7 dilution tube
were plated and incubated for 18 h and the number of colonies were counted. Growth of H. pylori was confirmed by the CLO R test. All berry extracts significantly (p 0.05) inhibited H. pylori, compared with controls, and also increased susceptibility of H. pylori to clarithromycin, with OptiBerry R demonstrating maximal effects.

Previous clinical research has suggested that the consumption of cranberry products prevents the adhesion of Escherichia coli to uroepithelial cells by causing changes in bacterial fimbriae. Atomic force microscopy was used to probe the adhesion forces between E. coli (nonfimbriated strain HB101 and the P-fimbriated variant HB101pDC1) and a model surface (silicon nitride), to determine the effect of growth in cranberry products on bacterial adhesion. Bacteria were grown in tryptic soy broth supplemented with either light cranberry juice cocktail (L-CJC) or cranberry proanthocyanidins (PACs). Growth of E. coli HB101pDC1 and HB101 in L-CJC or PACs resulted in a decrease in adhesion forces with increasing number of cultures. In a macroscale bacteria-uroepithelial cell adhesion assay a decrease in bacterial attachment was observed for E. coli HB101pDC1 grown in L-CJC or PACs. This effect was reversible because bacteria that were regrown in cranberry-free medium regained their ability to attach to uroepithelial cells, and their adhesion forces reverted to the values observed in the control condition. Exposure to increasing concentrations of L-CJC resulted in a decrease of bacterial attachment to uroepithelial cells for the P-fimbriated strain after L-CJC treatment (27% by weight) and after PACs treatment (345.8 microg/mL). Cranberry products affect the surface properties, such as fimbriae and lipopolysaccharides, and adhesion of fimbriated and nonfimbriated E. coli. The concentration of cranberry products and the number of cultures the bacteria were exposed to cranberry determines how much the adhesion forces and attachment are altered.

BACKGROUND: Consumption of fruit and vegetables is associated with a decreased risk of heart disease and cancer. This has been ascribed in part to antioxidants in these foods inactivating reactive oxygen species involved in initiation or progression of these diseases. Non-nutritive anthocyanins are present in significant amounts in the human diet. However, it is unclear whether they have health benefits in humans.

AIM: To determine whether daily consumption of anthocyanin-rich cranberry juice could alter plasma antioxidant activity and biomarkers of oxidative stress.

METHODS: 20 healthy female volunteers aged 18-40 y were recruited. Subjects consumed 750 ml/day of either cranberry juice or a placebo drink for 2 weeks. Fasted blood and urine samples were obtained over 4 weeks. The total phenol, anthocyanin and catechin content of the supplements and plasma were measured. Anthocyanin glycosides were identified by tandem mass spectrometry (MS-MS). Vitamin C, homocysteine (tHcy) and reduced glutathione (GSH) were measured by HPLC. Total antioxidant ability was determined using electron spin resonance (ESR) spectrometry and by the FRAP assay. Plasma total cholesterol, high density lipoprotein (HDL), and low density lipoprotein (LDL) cholesterol and triglycerides (TG) were measured. Glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) activities were measured in erythrocytes. Urine was collected for analysis of malondialdehyde (MDA) by HPLC and 8-oxo-deoxyguanosine (8-oxo-dG) by ELISA. Endogenous and induced DNA damage were measured by single cell gel electrophoresis (SCGE) in lymphocytes.

RESULTS: Vitamin C, total phenol, anthocyanin and catechin concentrations and FRAP and ESR values were significantly higher in the cranberry juice compared with the placebo. Cyanidin and peonidin glycosides comprised the major anthocyanin metabolites [peonidin galactoside (29.2%) > cyanidin arabinoside (26.1%) > cyanidin galactoside (21.7%) > peonidin arabinoside (17.5%) > peonidin glucoside (4.1%) > cyanidin glucoside (1.4 %)]. Plasma vitamin C increased significantly (P0.01) in volunteers consuming cranberry juice. No anthocyanins (plasma) or catechins (plasma or urine) were detectable and plasma total phenols, tHcy,TC,TG,HDL and LDL were unchanged. The antioxidant potential of the plasma, GSH-Px, CAT and SOD activities, and MDA were similar for both groups. Supplementation with cranberry juice did not affect 8-oxo-deoxyguanosine in urine or endogenous or H(2)O(2)-induced DNA damage in lymphocytes.

CONCLUSIONS: Cranberry juice consumption did not alter blood or cellular antioxidant status or several biomarkers of lipid status pertinent to heart disease. Similarly, cranberry juice had no effect on basal or induced oxidative DNA damage. These results show the importance of distinguishing between the in vitro and in vivo antioxidant activities of dietary anthocyanins in relation to human health.

BACKGROUND: Cranberry products have been implicated in several case reports to enhance the anticoagulant effect of warfarin. The mechanism could involve inhibition of the hepatic CYP2C9-mediated metabolic clearance of warfarin by components in cranberry. Because dietary/natural substances vary substantially in bioactive ingredient composition, multiple cranberry products were evaluated in vitro before testing this hypothesis in vivo.

METHODS: The inhibitory effects of five types of cranberry juices were compared with those of water on CYP2C9 activity (S-warfarin 7-hydroxylation) in human liver microsomes (HLM). The most potent juice was compared with water on S/R-warfarin pharmacokinetics in 16 healthy participants given a single dose of warfarin 10 mg.

RESULTS: Only one juice inhibited S-warfarin 7-hydroxylation in HLM in a concentration-dependent manner (P 0.05), from 20% to >95% at 0.05% to 0.5% juice (v/v), respectively. However, this juice had no effect on the geometric mean AUC(0-∞) and terminal half-life of S/R-warfarin in human subjects.

CONCLUSIONS: A cranberry juice that inhibited warfarin metabolism in HLM had no effect on warfarin clearance in healthy participants. The lack of an in vitro-in vivo concordance likely reflects the fact that the site of warfarin metabolism (liver) is remote from the site of exposure to the inhibitory components in the cranberry juice (intestine).

OBJECTIVES: The aim of this study was to determine whether consumption of sweetened dried cranberries elicits urinary anti-adherence properties against Escherichia coli as previously demonstrated with cranberry juice and/or sweetened cranberry juice cocktail, compared to unsweetened raisins.

DESIGN: Uropathogenic E. coli isolates were obtained from five women with culture-confirmed urinary tract infections (UTIs). Four urine samples were collected from each subject. The first urine sample was collected before any study intervention. The second urine sample was collected 2-5 hours after consumption of one box (42.5 g) of raisins. The third urine sample was collected 5-7 days later. The final urine sample was collected 2-5 hours after consumption of approximately 42.5 g of dried cranberries.

MATERIALS AND METHODS: E. coli isolates were incubated separately in each of the four urine samples collected from the five subjects. Bacteria were harvested from the urine and tested for the ability to prevent adhesion of P-fimbriated E. coli bacteria using a mannose-resistant hemagglutination assay with human red blood cells (A1, Rh+).

RESULTS: Of the urine samples collected after dried cranberry consumption, one demonstrated 50% antiadherence activity, two demonstrated 25% activity, and two did not show any increased activity. None of the control urine samples and none of the postraisin consumption samples demonstrated any inhibitory activity.

CONCLUSIONS: Data from this pilot study on only five subjects suggest that consumption of a single serving of sweetened dried cranberries may elicit bacterial antiadhesion activity in human urine, whereas consumption of a single serving of raisins does not. Further studies are needed to verify the antiadhesion effect of sweetened dried cranberries. In addition, dose-response and pharmacokinetics of the active compounds in the dried cranberries need to be determined. If clinical research is positive, dried cranberries could potentially be a viable alternative to cranberry juice consumption for prevention of UTIs.

OBJECTIVES: To compare the effectiveness of cranberry extract with low-dose trimethoprim in the prevention of recurrent urinary tract infections (UTIs) in older women.

PATIENTS AND METHODS: One hundred and thirty-seven women with two or more antibiotic-treated UTIs in the previous 12 months were randomized to receive either 500 mg of cranberry extract or 100 mg of trimethoprim for 6 months.

RESULTS: Thirty-nine of 137 participants (28%) had an antibiotic-treated UTI (25 in the cranberry group and 14 in the trimethoprim group); difference in proportions relative risk 1.616 (95% CI: 0.93, 2.79) P = 0.084. The time to first recurrence of UTI was not significantly different between the groups (P = 0.100). The median time to recurrence of UTI was 84.5 days for the cranberry group and 91 days for the trimethoprim group (U = 166, P = 0.479). There were 17/137 (12%) withdrawals from the study, 6/69 (9%) from the cranberry group and 11/68 (16%) from the trimethoprim group (P = 0.205), with a relative risk of withdrawal from the cranberry group of 0.54 (95% CI: 0.19, 1.37).

CONCLUSIONS: Trimethoprim had a very limited advantage over cranberry extract in the prevention of recurrent UTIs in older women and had more adverse effects. Our findings will allow older women with recurrent UTIs to weigh up with their clinicians the inherent attractions of a cheap, natural product like cranberry extract whose use does not carry the risk of antimicrobial resistance or super-infection with Clostridium difficile or fungi.

BACKGROUND: Ingestion of cranberry (Vaccinium macrocarpon Ait.) has traditionally been utilized for prevention of urinary tract infections. The proanthocyanidins (PACs) in cranberry, in particular the A-type linkages have been implicated as important inhibitors of primarily P-fimbriated E. coli adhesion to uroepithelial cells. Additional experiments were required to investigate the persistence in urine samples over a broader time period, to determine the most effective dose per day and to determine if the urinary anti-adhesion effect following cranberry is detected within volunteers of different origins.

METHODS: Two separate bioassays (a mannose-resistant hemagglutination assay and an original new human T24 epithelial cell-line assay) have assessed the ex-vivo urinary bacterial anti-adhesion activity on urines samples collected from 32 volunteers from Japan, Hungary, Spain and France in a randomized, double-blind versus placebo study. An in vivo Caenorhabditis elegans model was used to evaluate the influence of cranberry regimen on the virulence of E. coli strain.

RESULTS: The results indicated a significant bacterial anti-adhesion activity in urine samples collected from volunteers that consumed cranberry powder compared to placebo (p 0.001). This inhibition was clearly dose-dependent, prolonged (until 24 h with 72 mg of PAC) and increasing with the amount of PAC equivalents consumed in each cranberry powder regimen. An in vivo Caenorhabditis elegans model showed that cranberry acted against bacterial virulence: E. coli strain presented a reduced ability to kill worms after a growth in urines samples of patients who took cranberry capsules. This effect is particularly important with the regimen of 72 mg of PAC.

CONCLUSIONS: Administration of PAC-standardized cranberry powder at dosages containing 72 mg of PAC per day may offer some protection against bacterial adhesion and virulence in the urinary tract. This effect may offer a nyctohemeral protection.

OBJECTIVES: Recent anecdotal, unvalidated case reports have suggested potentiation of warfarin-induced anticoagulation by cranberry juice, possibly through inhibition of human cytochrome P450 (CYP) 2C9, the enzyme responsible for the clearance of the active S-enantiomer of warfarin. To address this question, the effect of cranberry juice and other beverages on CYP2C9 activity was evaluated in vitro and in vivo.

METHODS: The effects of 4 beverages on CYP2C9 activity were studied in human liver microsomes, by use of flurbiprofen hydroxylation as the index reaction. In a clinical study 14 healthy volunteers received 100 mg flurbiprofen on 5 occasions in a crossover fashion, with at least 1 week separating the 5 trials. Flurbiprofen was preceded in random sequence by the following: (1) cranberry juice placebo (8 oz), (2) cranberry juice (8 oz), (3) brewed tea (8 oz), (4) grape juice (8 oz), and (5) fluconazole, a CYP2C9 inhibitor serving as a positive control, with 8 oz of water.

RESULTS: Flubiprofen hydroxylation in vitro was reduced to 11% +/- 8% of control by 2.5% (vol/vol) brewed tea, to 10% +/- 7% of control by grape juice, to 56% +/- 16% of control by cranberry juice, to 85% +/- 5% of control by cranberry juice placebo, and to 21% +/- 6% of control by the index inhibitor sulfaphenazole (2.5 micromol/L) (P .01 for all comparisons versus control). Flurbiprofen clearance (29-33 mL/min) and elimination half-life (3.3-3.4 hours) did not differ significantly among trials 1, 2, 3, and 4. However, clearance in the fluconazole treatment condition (trial 5) was significantly reduced compared with the placebo control (17 +/- 5 mL/min versus 31 +/- 8 mL/min, P .05), and the half-life was prolonged (5.3 +/- 1.6 hours versus 3.3 +/- 0.8 hours, P .05). Formation of 4-hydroxyflurbiprofen was correspondingly reduced by fluconazole (P .05).

CONCLUSIONS: Although grape juice and tea impaired CYP2C9 activity in vitro, none of the 3 beverages altered CYP2C9-mediated clearance of flurbiprofen in humans, making a pharmacokinetic interaction with warfarin highly unlikely.