COSMETIC OR DERMATOLOGICAL COMPOSITIONS

Abstract

The invention relates to an alkaline hydrolysate of oyster meat, and to the cosmetic and dermatological uses thereof for treating signs of ageing such as wrinkles or blemishes or for improving the firmness of the skin and achieving a skin-firming effect.

Claims

1. An oyster extract obtained by alkaline hydrolysis of oyster meat at pH comprised between 8 and 13, particularly between 9 and 12 and without the addition of any external enzyme, particularly without the addition of any external proteolytic enzyme.

2. The oyster extract as claimed in claim 1 comprising in % by weight, in relation to the dry matter of the extract, from 1% to 10% free amino acids; from 3% to 12% proteins or peptides, from 0.005% to 0.05% total sugars and from 0.1% to 1% polyphenols.

3. A dermatological or cosmetic composition comprising an oyster extract as claimed in claim 1 or 2 and a dermatologically or cosmetically acceptable excipient.

4. The composition as claimed in claim 3, characterized in that the amount of oyster extract is comprised between 0.01% and 10% by weight in relation to the total weight of the composition.

5. The composition as claimed in one of claim 3 or 4, characterized in that the composition is in oral or topical form, preferentially in topical form.

6. The cosmetic composition as claimed in one of claims 3 to 5 for use in the prevention and/or treatment of skin disorders, said cosmetic composition comprising, as active principle, an oyster extract as claimed in one of claim 1 or 2 in combination with a cosmetically acceptable excipient.

7. The composition for its use as claimed in claim 6, characterized in that skin disorders are manifested by changes in the texture, color and transparency of the skin, and the appearance of wrinkles.

8. The composition for use as claimed in one of claim 6 or 7, characterized in that the skin disorders are the result of environmental stress.

9. The composition for use as claimed in claim 8 characterized in that environmental stress is caused by the sun, tobacco.

10. The composition for use as claimed in one of claims 6 to 9, characterized in that the composition is in oral or topical form, preferentially in topical form.

11. The composition for use as claimed in claim 10, characterized in that the topical form is selected from the group consisting of creams, gels, ointments and sprays.

12. The composition for use as claimed in claim 10, characterized in that the oral form is selected from the group comprising tablets, capsules and powders for oral suspensions.

13. The composition as claimed in one of claims 3 to 5 for use in improving the signs associated with skin aging, in particular selected from: the improvement of wrinkles, the improvement of skin firmness and the obtaining of a skin tensor effect, the treatment of age spots and lightening of the complexion.

14. A dermatological composition comprising an oyster extract as claimed in one of claim 1 or 2 and a dermatologically acceptable excipient, for use in the treatment of wound healing and skin irritation.

Description

EXAMPLE 1

Oyster Meat Collection

[0083] Collection environment: in a closed room.

[0084] Material to be collected=milky oysters with “clean” shells (brush and rinse the shells well before opening);

[0085] Equipment and accessories=freezer bags +ice tray that will be used to put the bags of oyster meat.

[0086] The oysters are opened and the meat (mantle, muscle, milt) is removed and placed in a bag on ice.

[0087] Once closed, the bag is weighed and stored for up to another 30 minutes on the ice before placing the bag in the freezer at −18° C. or −20° C.

EXAMPLE 2

Obtaining the Extract by Alkaline Hydrolysis and Characterization

[0088] The extract resulting from alkaline hydrolysis is made from frozen “milky” oysters, kept in dry ice as soon as they are extracted from the shell.

[0089] The hydrolytic approach chosen is the alkaline route, and more particularly a 1 M NaOH solution.

[0090] The oyster meat (approx. 200 g drained and thus freed of vegetation water) is mixed with 200 ml of a 1 M NaOH solution in order to obtain a pH value of the solution of about 10 to 11.

[0091] After a contact time of 6 hours under stirring at room temperature and in darkness, the mixture is then neutralized with citric acid to obtain a pH of about 4.7.

[0092] The mixture is filtered on a cellulose filter and then concentrated under vacuum so as to obtain 4 g of extract per 1 g of fresh oyster. The extract thus obtained has a dry matter content of 10%.

[0093] The extract obtained has the following characteristics:

TABLE-US-00001 Amount (in % by weight in relation to the dry matter Oyster extract of the extract) Protein  7.8% Total polyphenols  0.3% Total sugars 0.01% Free amino acids    2%

Protein Determination

[0094] Total proteins are tested according to the Lowry method. For this colorimetric assay, a standard curve OD750 nm=f(amount of proteins) is prepared. The reference protein used in this experiment is bovine serum albumin (BSA). The determination of the total amount of proteins in each extract is obtained using the same protocol as that carried out for the standard range.

Polyphenol Determination

[0095] Total polyphenols are evaluated using the Folin-Ciocâlteu reagent method. For this colorimetric assay, a standard curve OD720 nm=f is prepared using increasing concentrations of a reference molecule. The reference polyphenol used in this experiment is gallic acid. The determination of the total amount of polyphenols in each extract is obtained using the same protocol as that carried out for the standard range.

Sugar Determination

[0096] Total sugars are evaluated using the sulfuric acid-anthrone hydrolysis method. For this colorimetric assay, a standard curve OD578 nm=f is prepared from increasing concentrations of a reference molecule. The reference sugar used in this experiment is glucose. The determination of the total amount of sugars in each extract is obtained using the same protocol as that performed for the standard range.

EXAMPLE 3

Studies of Biological Properties of the Extract

[0097] The extract used is that obtained according to example 1, with a dry matter content of 10%.

[0098] It is used after dilution in ultrapure water. The concentrations of the extract are: 0.5%, 1.5% and 4.5% w/v (in grams of extract per 100 mL of water).

[0099] Bench test with collagen microbeads/Measurement of the tensor effect. In this model, freeze-dried 8-mm-diameter collagen discs are used. The contraction of these discs in response to different treatments is measured by image analysis. The more the surface area of the collagen discs decreases, the greater the tensor effect of the active agents.

[0100] The reference product used in this study is bovine serum albumin at 100 mg/ml.

[0101] The 8-mm-diameter collagen discs are soaked with 40 μl ultrapure water (control), the reference product and increasing concentrations of the test product. [0102] RESULT Tensor effect [0103] For extract at 1.5%/result+49.4%; [0104] For Extract at 4.5%/result+56.5%

[0105] Tests on normal human skin cell cultures/melanin inhibition:

[0106] This study model uses normal human melanocytes obtained from the foreskin of a 4-year-old donor. The melanocytes are isolated and cultured in a monolayer until confluence. The cells are then incubated for 72 H in the absence (control) or presence of a reference product (positive control) or increasing concentrations of the product to be tested.

[0107] The reference product (positive controls) is kojic acid at 250 μM.

[0108] At the end of the incubation period, the amount of intracellular melanin is evaluated in the cell lysate by spectrophotometric measurement at 405 nm.

[0109] RESULT Melanin Inhibitory Effect:

[0110] Extract at 0.5%; Result: −17.1%.

Stimulatory Effect on the Production of Procollagen Type I

[0111] This study model uses normal human fibroblasts obtained from a 68-year-old female donor. The fibroblasts are isolated and cultured in a monolayer until confluence. The cells are then incubated for 48 H in the absence (control) or presence of a reference product (positive control) or increasing concentrations of the product to be tested.

[0112] The reference product (positive controls) is TGF-Beta at 1 ng/ml and 10 ng/ml.

[0113] After 48 H of incubation, the amount of procollagen type I produced in the culture medium is evaluated using a sensitive and specific ELISA kit.

RESULT: Stimulation of Procollagen Type I Production:

[0114] Extract at 0.015%; Result+18%.

[0115] These results confirm the positive effect of an extract according to the invention in the treatment of wound healing following superficial skin injury or irritation. [0116] Enzyme Tests

Type I Collagenase Inhibitory Effect

[0117] This assay system is carried out with purified type I collagenases produced by Clostridium histolyticum, and a specific substrate detectable by a colorimetric method. The consumption of this substrate by type I collagenases is monitored by measurement of the optical density (OD) with a spectrometer at a wavelength of 405 nm every 3 minutes. The incubation period for these measurements is 45 minutes.

[0118] A reference control (namely EDTA at 2.5 mM) was used to verify the modulation capacity and in particular the inhibition capacity of the test enzymes.

RESULT on Type I Collagenase Inhibition

[0119] Extract at 0.15%; result: −67.3%.

[0120] Extract at 0.5%; result −82.2%.

[0121] Extract at 1.5%; result −91.1%.

Inhibitory Effect on Total Collagenases

[0122] This assay system is carried out with semi-purified collagenases derived from the culture medium of a normal human fibroblast culture, and a specific substrate detectable by a colorimetric method. The consumption of this substrate by the total collagenases is monitored by measurement of the optical density (OD) with a spectrometer at a wavelength of 405 nm every 3 minutes. The incubation period for these measurements is 45 minutes.

[0123] A reference control (namely EDTA at 2.5 mM) was used to verify the modulation capacity and in particular the inhibition capacity of the test enzymes.

RESULT on Total Collagenase Inhibition

[0124] Extract at 0.5%; result −18.7%.

[0125] Extract at 1.5%; result −44.7%.

CONCLUSION

[0126] The extract (at 10% dry matter), and this from the dose of 1%, shows a tensor effect which on the surface of the skin can bring a tension effect so as to erase wrinkles. The stimulation of the production of type I procollagen on fibroblast culture shows that the extract derived from alkaline hydrolysis of oyster meat improves the content of the extracellular matrix of the skin tissue by increasing the fibers associated with skin firmness. This capacity also makes it possible to envisage wrinkle filling. On the strength of this hypothesis, we rule out any decoy effect (the degradation of collagen fibers stimulates collagen production by reaction, therefore any stimulation of collagenase activity could claim to indirectly stimulate collagen production).

[0127] This performance is reinforced by the capacity of the extract to stop the degradation of collagen by inhibition of the type I collagenase enzyme and more generally of all collagenases, any decoy effect is thus ruled out, we observe a real biological capacity of the extract to stimulate type I procollagen. Finally, the extract limits melanin production of from the 0.5% dose, this property helps to limit age spots, but also to lighten the complexion.