Dosage effect on uropathogenic Escherichia coli anti-adhesion activity in urine following consumption of cranberry powder standardized for proanthocyanidin content: a multicentric randomized double blind study

Amy Howell (1) , Henry Botto (2) , Christophe Combescure (3) , Anne‐beatrice Blanc‐potard (4) , Lluis Gausa (5) , Tetsuro Matsumoto (6) , Peter Tenke (7) , Albert Sotto (4) , Jean-Philippe Lavigne (8, 4)

1 RU - Rutgers, The State University of New Jersey [New Brunswick]
2 Hôpital Foch [Suresnes]
3 UNIGE - Université de Genève = University of Geneva
4 Systèmes de sécrétion de type IV et virulence bactérienne
5 Fundación Puigvert [Barcelona, Spain]
6 Kyushu University
7 Central Hospital of Southern Pest [Budapest, Hungary]
8 CHU Nîmes - Hôpital Universitaire Carémeau [Nîmes]

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.

Mots clés: Bacterial Adhesion; Cranberry Juice; Adhesion Index; Cranberry Product; Nematode Growth Medium Agar Plate

Domaines: Maladies infectieuses; Urologie et Néphrologie; Bactériologie; Alimentation et Nutrition

Amy Howell, Henry Botto, Christophe Combescure, Anne‐beatrice Blanc‐potard, Lluis Gausa, et al.. Dosage effect on uropathogenic Escherichia coli anti-adhesion activity in urine following consumption of cranberry powder standardized for proanthocyanidin content: a multicentric randomized double blind study. BMC Infectious Diseases, 2010, 10, pp.94. ⟨10.1186/1471-2334-10-94⟩. ⟨hal-03247012⟩