FR2904546A1 - Use of herbal extract obtained e.g. from i.e. Theobroma cacao and/or at least another active agent e.g. to enhance augmentation of melanin synthesis in melanocytes of epidermis and to improve natural skin pigmentation - Google Patents

Abstract

Use of a vegetable extract (I) obtained from genus Amaranthus, genus Oryza or the species Pisum sativum L. (peas), Phaseolus vulgaris (bean) or Theobroma cacao (cocoa) mainly made of proteic/peptidic compounds, optionally in combination with another active agent, is claimed in the preparation of cosmetic, dermatologic and/or pharmaceutical composition, to enhance the augmentation of melanin synthesis in melanocytes of the epidermis or hair bulb and improves the natural pigmentation of the skin. ACTIVITY : Dermatological. MECHANISM OF ACTION : Melanogenesis stimulator. The ability of (I) to enhance the augmentation of the melanin synthesis in melanocytes of the epidermis was tested using human skin biopsies. The result showed that there was a sharp increase in the melanin synthesis and a stimulation of the whole process of melanin distribution in epidermis (after 48 hours of the treatment).

Description

i

The present invention relates to the use in a cosmetic composition or for the preparation of a pharmaceutical composition, of an effective amount of rice extract (Oryza sativa); the extract or the composition being intended to promote the increase of melanin synthesis in the melanocytes of the epidermis or hair bulb, with a view to giving it a tanned appearance, or to prepare the skin for exposure to the sun, or for therapeutic purposes, for repigmenting depigmented skin for example in the case of vitiligo, or for pigmenting hair or hair, particularly in the treatment and prevention of canities.

The color of human hair and skin is a function of various factors including seasons of the year, race, sex and age. It is mainly determined by the concentration of melanin produced by melanocytes. Melanocytes are specialized cells that, via particular organelles, melanosomes, synthesize melanin. The synthesis of melanin or melanogenesis is a complex process whose precise mechanisms are not yet elucidated and which schematically involves the following steps:

Tyrosine ^ Dopa ^ Dopaquinone ^ Dopachrome ^ Melanin

In the epidermis, the melanocyte is involved in the epidermal melanic unit which comprises a melanocyte surrounded by about 40 neighboring keratinocytes. As melanin is synthesized in the melanosomes, they move from the perinuclear region to the end of the melanocyte dendrites. By phagocytosis, the end of the dendrites is captured by keratinocytes, degraded membranes and redistributed melanosomes in the keratinocytes, where they will provide protection up to the natural desquamation of the cells. The production of melanin, as well as its transport, is regulated by various factors such as, for example, UV radiation, hormones or chemicals. Thus, an increase in exposure to UV radiation causes the synthesis of pigments and browning of the skin. The pigmentation of hair and hair requires the presence of melanocytes in the bulb of the hair follicle. The hair follicle is a tubular invagination of the epidermis that penetrates to the deep layers of the dermis. The melanocytes in the bulb of the hair follicle are in an active state, that is, they synthesize melanin. These pigments are transmitted to the keratinocytes intended to form the hair shaft, which will lead to the growth of a pigmented hair or hair. It is accepted that canitia (natural whitening of hair) is associated with a decrease of melanin in the hair shaft.

Nowadays, it is important to look good and tanned skin is always a sign of good health. However, natural tanning is not always without risk insofar as it requires prolonged exposures to UV radiation, which are likely in return to induce an alteration of skin cells, especially in the case of individuals of clear phototypes. The skin ages prematurely, becomes dry and is characterized by many wrinkles and age spots. It is therefore desirable to find an alternative to natural tanning that is compatible with the health requirements of individuals. On the other hand, we know that in most populations the maintenance of a constant coloring of the hair, sign of youth, is a strong aspiration. The search for compounds that can promote the synthesis of melanin in the skin and hair is a concern of dermatology and cosmetics. These new compounds are particularly useful as an alternative to sun exposure, to prepare the skin and protect it from the sun's rays, to obtain a tan more intense after exposure to the sun, to prolong the natural pigmentation of the skin after exposure to the sun. sun or to prevent and / or limit and / or stop the development of canities and even maintain the natural pigmentation of hair and / or gray or white hairs.

By natural pigmentation of the skin is meant the coloring of the skin or hair determined by the melanin concentration.

In this regard, many solutions have been proposed by adding exogenous dyes, the best known of which is dihydroxyacetone, or DHA. However, only the stimulation of the pigmentation of the skin and / or the hair by the natural way allows a real protection vis-à-vis the UV radiations and remains the ideal way of stimulation of the pigmentation. Thus, it has been proposed in the prior art the preparation and use of activators of melanin biosynthesis (FR828097, FR 2831438, FR 2845285) involving hormones (alpha MSH or its derivatives WO2006037188) or prostaglandins ( WO9511003).

On the other hand, there are pathologies related to pigmentation such as vitiligo which is an autoimmune disease characterized by the appearance on the skin of white patches related to a lack of pigmentation or pityriasis versicolor, a superficial mycosis. causing the appearance of light spots that may appear immediately or after exposure to the sun.

The main objective of the present invention is to provide a new active ingredient that significantly promotes the synthesis of melanin in the melanocytes of the epidermis and hair bulb. The inventors have in fact demonstrated a biological activity and, more particularly dermatological and cosmetic, of a rice extract (Oryza sativa). The use of rice extracts, in the field of cosmetics, has already been described in numerous patents such as patents US5853705 and JP9087133, in particular in terms of skin care. However, to the knowledge of the applicant, the use of rice extracts to promote the increase of melanin synthesis in the melanocytes of the epidermis or hair bulb, has not yet been exposed.

By pro-pigmenting active agent is meant a compound capable of promoting the increase of melanin synthesis in the melanocytes of the epidermis or hair bulb. By hair and hair is meant all the hairy appendages and in particular also the eyelashes and the eyebrows.

The compositions according to the invention may be applied by any appropriate route, in particular oral, parenteral or external topical, and their formulation will be adapted by those skilled in the art, in particular for cosmetic or dermatological compositions. Advantageously, the compositions according to the invention are intended for topical administration. They contain a physiologically acceptable medium, in particular a cosmetologically or pharmaceutically acceptable medium, in particular a dermatologically acceptable medium.

Thus, the subject of the invention is primarily the use in a composition, or for the preparation of such a composition, of an effective amount of rice extract; the extract or the composition being intended to promote the increase of melanin synthesis in the melanocytes of the epidermis or hair bulb.

The term "extract" refers to any isolated substance or preparation obtained from plant material. It is obtained, for example, by dissolving the active components by means of solvents (such as water, alcohol, etc.) then by concentration and purification of these active ingredients, for example by evaporation of the solvents. Any method of extraction or purification known to those skilled in the art can be used to prepare the extract according to the invention.

Rice is a cereal plant of the family Gramineae or Poaceae grown in tropical, subtropical and temperate regions. Rice is an annual hairless, thatchy (straw) erect or spreading plant of variable height. The fruit (or grain) is a caryopsis wrapped in two large, coriaceous and adherent lemmas, all forming the paddy. Rice belongs to the genus Oryza which comprises more than twenty species, two varieties of which are particularly cultivated:

Oryza sativa L., the most cultivated species, native to India; Oryza glaberrima Steud., African rice or Casamance rice, native to Africa

Central.

According to an advantageous embodiment of the invention, the active agent is obtained from an extract of plants of the species Oryza sativa L. Of course the rice extract can be prepared from plants of least one of the many varieties and species belonging to the genus Oryza.

More particularly according to the invention is used one of the many plants of the family of poaceae, of the genus oryza (rice) and preferably the species Oryza sativa L. According to the invention the plant material used will be the grain and preferentially the grain free of its envelope by a dehulling step. In a first step, the plant is ground using a plant grinder. The powder thus obtained may subsequently be "delipidated" with the aid of a conventional organic solvent (such as, for example, an alcohol, hexane or acetone).

The extraction of proteins from the plant is then conventionally carried out (Osborne, 1924); the crushed plant being suspended in an alkaline solution. The soluble fraction is collected after centrifugation and filtration steps, this crude solution then constituting a first form of the rice extract containing the proteins, carbohydrates and possibly lipids. Proteins are then precipitated by varying the ionic strength and acidifying the medium to remove soluble components and nucleic acids. The precipitate is then washed with a solvent such as, for example, ethanol or methanol and the solvent is evaporated by drying in vacuo. The protein-rich precipitate is redissolved in water or other solvent and then constitutes a more purified form of the extract. The extraction can also be carried out in neutral or acidic medium. The stage of precipitation is then carried out using a conventional precipitation agent such as salts (sodium chloride, ammonium sulfate). The precipitate obtained can be separated from the precipitating agents by dialysis after redissolving in water or another solvent. At this stage, the extract obtained contains at least 70% of compounds of protein and peptide nature.

The isolated protein fraction according to the invention is then hydrolyzed under mild conditions to generate polypeptides and soluble peptides. Hydrolysis is defined as a chemical reaction involving the cleavage of a molecule by water, this reaction being possible in a neutral, acidic or basic medium. According to the invention, the hydrolysis is carried out chemically and / or advantageously by proteolytic enzymes. We can then mention the use of endoproteases and exopeptidases of plant origin (papain, bromelain, ficin) and microorganisms (Aspergillus, Rhizopus, Bacillus, etc.). The resulting solution is the active rice extract. The active rice extract can be further purified by fractionation, in particular by a method of the chromatographic type or purified and concentrated by a dialysis process. Any of the more or less purified forms of the extract is then solubilized in water or in any mixture containing water, and then sterilized by ultrafiltration.

The plant extract obtained according to the invention is analyzed qualitatively and quantitatively for its content of compounds of protein and peptide nature. Protein and peptide compounds are understood to mean protein fragments, peptides and free amino acids present in the mixture. The peptides, amino acids and protein fragments are determined according to conventional techniques, which are well known to those skilled in the art.

Thus, according to an advantageous embodiment of the invention, the active plant extract contains a quantity of protein and peptide compounds representing between 30 and 90% of the total weight of the dry matter, more particularly this amount is between 60 and 90% of the total weight of the dry matter. and 80% of the total weight of the dry matter.

The invention has the second object the use in a cosmetic composition, or for the preparation of a pharmaceutical composition, of an effective amount of rice extract; the extract or the composition being intended to promote the pigmentation of the hairs and / or the hair. The invention also relates to the use in a cosmetic composition, or for the preparation of a pharmaceutical composition, of an effective amount of rice extract; the extract or the composition being intended to prepare the skin for exposure to the sun.

The invention also relates to the use in a cosmetic composition, or for the preparation of a pharmaceutical composition, of an effective amount of rice extract; the extract or the composition being intended, by increasing melanin synthesis, to protect the skin from sunlight.

According to another form of the invention, the use of the compound or the composition containing it is intended to protect the skin from environmental stress.

According to an advantageous embodiment of the invention, the rice extract is first solubilized in one or more cosmetically or pharmaceutically acceptable solvents such as water, glycerol, propylene glycol, butylene glycol, ethoxylated or propoxylated diglycols, ethanol, propanol or isopropanol.

According to yet another advantageous embodiment of the invention, the rice extract is first solubilized in a cosmetic or pharmaceutical vector such as liposomes or adsorbed on powdery organic polymers, mineral supports such as talcs and bentonites, and more generally solubilized in, or attached to, any cosmetically or pharmaceutically acceptable carrier.

To give an order of magnitude, in the cosmetic or dermatological compositions of the present invention, the rice extract is used in an amount representing from 0.0001% to 20% of the total weight of the composition, and preferably in an amount representing from 0.05% to 5% of the total weight of the composition.

In addition to the major advantage of the pigmentation of the skin in the sun protection, a pro-pigmenting compound according to the invention offers outlets in self-tanning products and promoting tanning. For this, the invention relates to the use of rice extract for the manufacture of products for artificial tanning and / or browning of the skin. The invention also relates to the use of rice extract to improve the intensity and / or the homogeneity and / or the persistence of the coloration produced on the skin and / or the hair.

The invention also relates to the use of rice extract to reduce pigment disorders associated with hypopigmentation of the skin, especially vitiligo.

Preferably, the compositions according to the present invention will be in a form suitable for topical administration to the skin, and cover all cosmetic or dermatological forms. These compositions must therefore contain a cosmetically and / or dermatologically acceptable medium, that is to say compatible with the skin, hair or hair. These compositions may especially be in the form of creams, O / W emulsions, W / O emulsions or multiple emulsions, solutions, suspensions, gels, milks, lotions, sticks or even powders, suitable for application to the skin, lips and / or the hair. These compositions comprise the excipients necessary for their formulation, such as solvents, thickeners, diluents, surfactants, antioxidants, dyes, preservatives, perfumes.

Of course, those skilled in the art will take care to choose any additional compounds, active or non-active, and / or their quantity, so that the advantageous properties of the mixture are not, or not substantially, impaired by the addition considered.

The composition that may be used according to the invention may in particular consist of a composition for hair care, and in particular a shampoo, a conditioner, a setting lotion, a treatment lotion, a cream or a styling gel, a restructuring lotion for hair, a mask, etc. The cosmetic composition according to the invention can be used in particular in treatments using an application that is followed or not followed by rinsing, or in the form of shampoo.

It can also be in the form of dye or mascara to be applied with a brush or a comb, in particular on eyelashes, eyebrows or hair.

Advantageously, the compositions that can be used according to the invention also contain at least one other agent that promotes the pigmentation of the skin, hair and / or hair. Such compounds are in particular tyrosinase substrates, such as tyrosine or L-DOP A, prostaglandins, or activating compounds of the cAMP pathway such as pro-opiomelanocortin derivatives, adenosine, or the forkoline or its derivatives. Plant extracts such as citrus aurantium (bitter orange) or chrysanthemum (Chrysanthemum morifolium), described in particular in patents FR 2845285 and EP1014934, may also be mentioned.

Such compounds are also found in the family of exogenous dyes of the superficial layers of the epidermis, such as dihydroxyacetone (DHA), erythrulose, extracts of henna leaves, described in particular in patents EP 0742002 and FR2779958.

The invention relates to a cosmetic process for increasing the synthesis of melanin in melanocytes and promoting the natural pigmentation of the skin and the hair, which consists in applying the composition as defined above to the skin or the hair.

The invention relates to a cosmetic treatment method for preventing or treating hair and hair whitening, comprising applying to the skin the composition as defined above.

Other advantages and characteristics of the invention will appear better on reading the examples given by way of illustration and not limitation.

Example 1 Preparation of extracts from rice {Oryza sativa L.)

The active agent is obtained from an extract of plants of the species Oryza sativa L. Of course the extract can be prepared from plants of at least one of the many varieties and species belonging to the genus Oryza.

In a first step, 1 kg of husked rice grains are delipidated by the action of an organic solvent: hexane. The rice grains are then milled in a knife mill and then suspended in an aqueous alkaline solution (1/10 dilution). This mixture is stirred for a time long enough to allow the solubilization of the soluble fractions. The extraction temperature is variable (between 4 and 80 ° C); preferably the operation will be performed cold. After this extraction phase, the medium is clarified by centrifugation and then filtered through a plate filter. This The filtrate which contains the soluble fractions of the rice is then subjected to protein precipitation by varying the ionic strength in neutral or acidic medium, which eliminates soluble carbohydrate components, lipids and nucleic acids. The supernatant is removed and the precipitate is then washed with a solvent such as, for example, ethanol or methanol and the solvent is evaporated by drying in vacuo.

At this stage, about 50 grams of light yellow powder of crude protein extract are obtained containing: Proteins: 75% Carbohydrates: 20% - Lipids: 5%

The protein-rich precipitate is dissolved in water or another solvent.

The extraction can also be carried out in neutral or acidic medium.

The crude protein extract is then subjected to a series of gentle and selective hydrolyses consisting of chemical and enzymatic hydrolyses. By way of example, mention may be made of hydrolysis in the presence of exopeptidases (papain, ficin).

The hydrolyzate is then purified and membrane-dialyzed to remove high molecular weight compounds.

A light-colored hydrolyzate titrant of 15 to 30 g / l of dry extract and containing a quantity of protein and peptide compounds representing approximately 70% of the total weight of the dry matter is then obtained. The hydrolyzate is then diluted so that the protein concentration determined by the method of Lowry is between

0.5 and 2 g / l.

Example 2 Ex Vivo Study of the Effect of the Compound on Melanin Synthesis

The purpose of this ex vivo study is to demonstrate the increase in melanization provided by the extract according to Example 1.

Protocol: Human skin biopsies 6 mm in diameter are maintained in culture ex vivo in the presence of a specific medium (DMEM lg / L, HAMF12, SVF and antibiotics) on inserts deposited in 6-well plates. The biopsies are cultured for 48 hours and receive or not 2 applications per day of extract according to Example 1 at a concentration of 1%. The biopsies are then fixed in 9% formalin, NaCl (150 mM) for 10 hours then included in paraffin. Skin sections 3 μm thick are then made and the melanin is stained specifically by the Fontana-Masson technique.

Results: Skin sections that did not receive the application of extract according to Example 1 have a low intensity coloration. On the other hand, the skin sections having received the rice extract applications according to Example 1 show a markedly increased color intensity. In addition, melanin is located in the basal layer, but also transported in the supra-basal layers.

Conclusions: 48 hours of treatment led to a strong increase of melanin synthesis by melanocytes and to stimulate the whole process of distribution of melanin in the epidermis.

Example 3 Preparation of compositions

These compositions were obtained by simple mixing of the various components. The quantities indicated are given as a percentage of weight.

1 - Oil-in-water emulsion

Oil phase: a Montanov 68 (Cetearyl Alcohol and Cetearyl Glucoside) a Jojoba Oil B Vaseline Oil Isopropyl Palmitate

Aqueous phase: a Glycerin has Allantoin an extract according to Example 1 to Sepigel 305 (Polyacrylamide and Cl 3- 14 Isoparaffin and Laureth-7) a Perfume Conservator

5.00%

5.00%

5.00%

7.00%

5.00%

0.10%

1.00%

0.30%

0.50 %qsp 100 %0.50%

0.50% qsp 100%

Water

2- Gel

Carbopol Ultrez 10 (2% solids)

triethanolamine

Extract according to example 1

Tory

EDTA (sequestering)

Perfume

Water

3- Lotion

B Mono Propylene Glycol Allantoin Glycerin

B Cetiol HE (PEG-7 Glyceryl Cocoate)

B Extract according to example 1 a Conservative

B Perfume fl Water

4-self-tanning oil-in-water emulsion

Oily phase: fl Mono / glycerol distearate blend f Stearyl alcohol fl Stearic acid palm oil fl Poly dimethylsiloxane fl Poly dimethylsiloxane mixture alpha-omega dihydroxyl / cyclopentadimethylsiloxane (14.7 / 85.3) fl Lauroyl isopropyl salcon phase aqueous: fl Dihydroxyacetone fl Glycerine fl Hexadecyl alcohol phosphate, potassium salt

25.00%

0.50%

5.00%

0.20%

0.10%

0.50% qsp 100%

1.00%

0.30%

1.00%

1.00%

0.5%

0.20%

qsp 100 %0.50%

qsp 100%

2.00%

1.00%

1.50%

2.00%

3.00%

15.00%

5.00% 5.00% 1.00% Polyacrylic acid

triethanolamine

Dl-alpha-tocopheryl acetate

Extract according to example 1

Demineralized Water

0.30% qsp pH: 7

0.50%

1.00% qsp 100.00%

2.00%

3.00%

10.00%

5.00%

3.00%

2.00%

5.00%

0.70%

1.00% qsp 100.00%

5.00%

0.40%

13.00%

7.00%

5.00%

0.25%

qsp 100.00 %1.00%

qsp 100.00%

66.80% 5.00%

5-Self-tanning water-in-oil emulsion

Oily Phase: Polydimethyl / methylcetylmethylsiloxane oxyethylenylphenyltrimethylsiloxytrisiloxane Lauroyl isopropyl sarcosinate floxhexadecane Cyclopenta dimethylsiloxane

Aqueous Phase: Dihydroxyacetone Fl Glycerine Magnesium Sulfate Extract According to Example 1 Demineralized Water

6-Self-tanning lotion Dihydroxyacetone fl u Freeze-dried extract of Eclipta prostata fl Ethanol 96% fl Ethoxydiglycol fl PPG-1-PEG-9-Lauryl Glycol Ether Fl Parabens Fl Extract according to Example 1 Demineralized water

7- Emulsion oil in self-tanning water fl Water fl Ethoxydiglycol 0.30%

0.30%

2.00%

2.00%

2.00%

2.00%

1.00%

1.00%

1.00%

1.00%

0.25%

0.1%

0.1%

10.975%

2.00%

0.60%

0.40%

0.05%

1.00 %0.025%

1.00%

B Xanthan gum

B Cetyl hydroxyethylcellulose, Cetyl alcohol, Stearyl alcohol, Octyl palmitate a Glucam, P-20 distearate, Steareth-20, Dimethicone, Polysorbate 60, Dimethicone, Copolyol, IPDI, Copolymer, Glycerylstearate, and PEG-100 Actiplex stearate, 335 Lipo OP, Tocopheryl acetate, Water a Dihydroxyacetone to Nipaguard MPA to Panthenol, 50% aqueous Sorbic Acid Sodium metabisulfite Extract according to Example 1

Claims (6)

1. Use of an effective amount of at least one plant extract obtained from plants of the genus Oryza, alone or in combination with at least one other active agent, in or for the preparation of a cosmetic and / or dermatological composition and / or pharmaceutical, the extract or composition containing it being intended to promote the increase of melanin synthesis in the melanocytes of the epidermis or hair bulb and improve the natural pigmentation of the skin. 2. Use according to claim 1, characterized in that the plants belong to the genus Oryza, and more particularly to the species Oryza sativa L., and more particularly grain or caryopsis of said plants. 3. Use according to one of the preceding claims, characterized in that the composition is in a form suitable for topical application comprising a cosmetically or dermatologically acceptable medium. 4. Use according to any one of the preceding claims, characterized in that the rice extract is used in an amount representing from 0.0001% to 20% of the total weight of the composition, and preferably in a quantity representing from 0 , 05% to 5% of the total weight of the composition. 5. Use according to any one of the preceding claims, characterized in that the composition further contains at least one exogenous dye of the surface layers of the epidermis and / or at least one pro-pigmenting active agent different from said rice extract, selected from tyrosinase substrates or prostaglandins or activating compounds of the cAMP pathway or plant extracts pigmenting. 6. Use according to any one of the preceding claims, characterized in that the extract or the composition containing it is intended, by increasing melanin synthesis, to prepare the skin for exposure to the sun or to protect the skin. radiation from the sun. 7. Use according to any one of the preceding claims characterized in that the extract or composition containing it is intended to protect the skin from external aggressions, in particular UV rays. 8. Use according to any one of the preceding claims characterized in that the extract or the composition containing it are intended for artificial tanning and / or browning of the skin. 9. Use according to any one of the preceding claims characterized in that the extract or the composition containing it are intended to improve the intensity and / or homogeneity and or the persistence of the pigmentation of the skin and / or hair. 10. Use according to any one of the preceding claims characterized in that the extract or the composition containing it is intended to attenuate a pigmentary disorder of the skin, especially vitiligo. 11. Use according to any one of the preceding claims characterized in that the extract or the composition containing it are intended to prevent or treat the whitening of the hair and / or hair. 12. Cosmetic treatment process intended to promote the increase of melanin synthesis in melanocytes, characterized in that a composition as defined according to any one of Claims 1 to 5 is applied topically to the zone to be treated. .