COMPOSITION FOR THE TREATMENT AND PREVENTION OF URINARY TRACT INFECTIONS

Abstract

A pharmaceutical composition or dietary supplement is described that is effective in the treatment and prevention of urinary tract infections, comprising a combination of D-mannose, proanthocyanidins, hydroquinone derivatives and zinc.

Claims

1. A pharmaceutical composition or dietary supplement comprising, as the active ingredients, D-mannose, proanthocyanidins, hydroquinone derivatives and zinc, for use in the treatment or prevention of urinary tract infections.

2. The pharmaceutical composition or dietary supplement according to claim 1, comprising a cranberry (Vaccinium macrocarpon, Aiton) extract as the proanthocyanidins source, said extract preferably having a proanthocyanidins titre of 7.2%.

3. The pharmaceutical composition or dietary supplement according to claim 2, wherein the extract comprises a cranberry phytocomplex.

4. The pharmaceutical composition or dietary supplement according to claim 1, comprising an Arctostaphylos uva-ursi (Arctostaphylos uva-ursi (L) Spreng.) extract as the hydroquinone derivatives source, the extract being preferably a leaf extract and having preferably a hydroquinone derivatives titre of 20%.

5. The pharmaceutical composition or dietary supplement according to claim 1, comprising zinc bisglycinate chelate as the zinc source.

6. The pharmaceutical composition or dietary supplement according to claim 1, in a dosage form comprising: from 450 to 550 mg of D-mannose, preferably about 500 mg of D-mannose; from 200 to 300 mg of cranberry extract, preferably about 250 mg of cranberry extract; from 100 to 150 mg of Arctostaphylos uva-ursi extract, preferably about 125 mg of Arctostaphylos uva-ursi extract; and from 5 to 10 mg of zinc, preferably about 6.25 mg of zinc.

7. The pharmaceutical composition or dietary supplement according to claim 1, which is in an oral dosage form.

8. The pharmaceutical composition or dietary supplement according to claim 1, wherein the urinary tract infection is a bacterial infection.

9. The pharmaceutical composition or dietary supplement according to claim 1, for use in oral administration, wherein said use comprises the administration of from 450 to 1100 mg/day of D-mannose, from 200 to 600 mg/day of cranberry fruit extract, from 100 to 300 mg/day of Arctostaphylos uva-ursi extract and from 5 to 20 mg/day of zinc.

10. The composition according to claim 1, further comprising pharmaceutically acceptable excipients and/or binders and/or vehicles.

Description

FORMULATION EXAMPLE—3-g Sachet

[0020]

TABLE-US-00001 D-mannose 500 mg Cranberry dry extract 250 mg of which proanthocyanidins  18 mg Arctostaphylos uva-ursi dry extract 125 mg of which hydroquinone derivatives  25 mg Zinc (from zinc bisglycinate) 6.25 mg 

[0021] The recommended dose is one or two daily sachets.

EXPERIMENTAL SECTION

Rationale

[0022] Urinary tract infections are among the most commonly encountered infections both in the community and at the nosocomial level. Generally they result from colonization by the ascending route, by microorganisms of enteric origin, for example Escherichia coli. E. coli is in fact considered to be responsible for about 90% of urinary tract infections contracted in the community and for the majority of nosocomial infections. The first step in the pathogenesis of urinary tract infections is represented by adhesion of the pathogen to the uroepithelial cells, which is often mediated by bonds of specific bacterial structures, such as fimbriae.

[0023] In recent years it has been demonstrated that administration of cranberry proves effective in reducing the incidence of urinary tract infections, especially those caused by E. coli, in particular preventing recurrent infections. This action seems to be due principally to the interaction of the proanthocyanidins contained in cranberry with the adhesins present on the fimbriae of E. coli. This interaction results in a conformational change of the P fimbriae, which leads to a decrease in the bacterium's capacity for adhesion to the uroepithelial cells.

Purpose of the Study

[0024] The present study had a dual purpose: [0025] 1. Evaluation of antibacterial activity by determining the minimum inhibitory concentration (MIC) with respect to 10 strains of E. coli isolated clinically, responsible for urinary tract infections. [0026] 2. Evaluation of the interference of sub-inhibitory concentrations of the test product on the adhesiveness of E. coli to uroepithelial cells by light microscopy and scanning electron microscopy.

MATERIALS AND METHODS

Ivuxur

[0027] The following experimental tests used the formulation in sachets of the Formulation Example given above, called Ivuxur. For these experiments, Ivuxur was suspended in brain-heart infusion broth (BHI) at a concentration of 100 mg/mL, obtaining partial dissolution of the product.

Bacterial Strains

[0028] Ten strains of E. coli isolated in the Laboratory for Chemical, Clinical and Microbiological Analysis of IRCCS Galeazzi from subjects with urinary tract infection without any connection between them were taken into consideration. The strains had a varying profile of antibiotic sensitivity. They were frozen at −80° C. in BHI+10% glycerol until use.

Determination of the Minimum Inhibitory Concentration (MIC)

[0029] The MIC of the test product (Ivuxur) was determined by the method of microdilution in broth according to the EUCAST protocol. In particular, the wells of a microtitration plate containing scalar dilutions of Ivuxur were inoculated with a bacterial suspension (bacterial load 10.sup.8 CFU/mL) in such a way that each well contained 10.sup.5 CFU of bacteria. For each bacterial strain, one well not containing the compound was used as growth control. After incubation for 16-18 h at 37° C. in an aerobic atmosphere, MIC was determined as the lowest concentration of the compound capable of inhibiting bacterial growth.

Evaluation of the Interference of Sub-Inhibitory Concentrations of Ivuxur on Bacterial Adhesiveness

Uroepithelial Cells

[0030] The uroepithelial cells were obtained from apparently healthy women (aged 22-45 years), who had not received antibiotic treatment for at least 1 month. The cells were washed 3 times with PBS in order to remove any adhering bacteria and were resuspended at a final concentration of 1×10.sup.5 cells/mL.

Bacterial Strains

[0031] To evaluate the anti-adhesive activity of the compound, two strains of E. coli were used (E. coli 22 and E. coli 36) with different sensitivity to the test compound (Table 1) and a different profile of antibiotic sensitivity, representative of those used in the preceding step of the study. Each strain was incubated for 24 h in BHI broth in the presence of concentrations of Ivuxur equal to ½ and ¼ MIC. At the end of the incubation period, after washing several times with PBS by centrifugation, an inoculum equal to 1×10.sup.8 CFU/mL was incubated.

Test of Adhesiveness

[0032] The uroepithelial cells collected, as described above, were incubated with the 2 bacterial strains (1×10.sup.8 CFU/mL) grown in the presence or in the absence of Ivuxur at the concentrations stated above. After incubation for 1 hour at 37° C. in an atmosphere containing 5% CO.sub.2, the non-adhering bacteria were removed by washing 3 times with PBS, after the last of which the pellet obtained was resuspended in a small amount of PBS. 10 μL of the suspension obtained was deposited on a microscope slide and, after fixing in methanol, was submitted to Gram staining. Another aliquot was deposited on a slide for electron microscopy and, after fixing with glutaraldehyde, it was treated for observation in scanning electron microscopy.

[0033] The number of adherent bacteria per cell was determined by counting, in the light microscope, the bacteria adhering to 40 cells, and calculating the average value. The counts of the bacteria adhering to 40 cells were carried out in duplicate by two independent observers. Each experiment was carried out in duplicate.

[0034] The index of inhibition of adhesiveness was calculated using the following formula:

I.A. (%)=100−(average number of adherent bacteria per cell after treatment with Ivuxur/average number of untreated bacteria per cell)×100

RESULTS

Antibacterial Activity

[0035] The MIC values obtained for the 10 strains of E. coli considered are given in Table 1. The concentrations of Ivuxur capable of inhibiting growth of the strains under consideration were found to be between 25 and 100 mg/mL. The concentration capable of inhibiting growth of 50% of the strains (MIC50) was equal to 50 mg/mL while that capable of inhibiting growth of 90% (MIC90) of the strains examined was equal to 100 mg/mL.

Anti-Adhesive Activity

[0036] For evaluating the anti-adhesive capacity of Ivuxur, two strains of E. coli were used, displaying different sensitivity to the test compound: E. coli 22 (MIC 25 mg/mL) and E. coli 36 (MIC 50 mg/mL).

[0037] Table 2 gives the number of adherent bacteria per cell after treatment with sub-inhibitory concentrations of Ivuxur. It can be seen that there is a marked reduction in bacteria capable of adhering to uroepithelial cells after incubation for 12 hours with the test compound, relative to the same bacteria grown in the absence of Ivuxur. The anti-adhesive activity is found to be concentration-dependent, and is more marked for concentrations equal to ½ MIC for both bacteria. The index of inhibition of adhesiveness was equal to 72±8.54% for ½ MIC and 52.8±8.78% for ¼ MIC.

[0038] The anti-adhesive activity of Ivuxur was confirmed by examination by scanning electron microscopy. The number of adherent bacteria in one uroepithelial cell was notably reduced after incubation of the bacteria with sub-inhibitory concentrations of the compound being evaluated.

CONCLUSIONS

[0039] Ivuxur demonstrated notable anti-adhesive capacity with respect to E. coli that are responsible for urinary tract infections.

TABLE-US-00002 TABLE 1 Antibacterial activity of Ivuxur with respect to E. coli Strain MIC (mg/mL) E. coli 22 25 E. coli 23 50 E. coli 24 50 E. coli 25 100 E. coli 27 100 E. coli 28 50 E. coli 33 50 E. coli 34 100 E. coli 35 50 E. coli 36 50

TABLE-US-00003 TABLE 2 Anti-adhesive activity of Ivuxur with respect to E. coli Control ½ MIC ¼ MIC Strain No. of adherent bacteria/cell E. coli 22 25.4 8.6 13.03 E. coli 36 41.6 8.98 17.01