EP2139445A2

EP2139445A2 - Use of gamma-aminobutyric acid as a depigmentation agent

Info

Publication number: EP2139445A2
Application number: EP07870351A
Authority: EP
Inventors: Marcel Cohen
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-11-30
Filing date: 2007-11-29
Publication date: 2010-01-06
Also published as: AP2495A; WO2008081095A3; FR2909280A1; US20090232757A1; AP2009004796A0; CN101568324A; KR20090103992A; FR2909280B1; JP2010511021A; WO2008081095A2

Abstract

The invention pertains to the field of cosmetics and essentially relates to skin and phanera care. The invention more particularly relates to the use, in the form of cosmetic compositions, of gamma-aminobutyric acid, or a salt thereof, with an inorganic or organic acid or a derivative thereof, such as an ester, in cosmetic compositions in a concentration of 0.4-10 % alone or in combination with a polyphenol- or tannin-rich plant extract and/or an alpha-hydroxylated acid in an aqueous or oily carrier. Use as a depigmentation agent for the skin or teguments with 1 to 4 applications per day.

Description

Use of gamma-aminobutyric acid as a depigmenting agent

The present invention relates to the necessities of life and more particularly to body care.

More specifically, it relates to cosmetic compositions intended to ensure lightening of the skin, in particular in the case of aesthetic defects related to abnormal or excessive irregular pigmentation or intended to ensure the lightening of normal skin to move from one skin to another. dark phenotype to a lighter phenotype.

In addition, the compositions according to the invention find use in fair skinned subjects to mitigate the effects of chloasma or ephelides.

The present invention specifically relates to the use of gamma-aminobutyric acid (GABA) or its salts or its derivatives for the production of depigmenting compositions intended to be applied to the skin and the integuments.

Gamma-aminobutyric acid has already found uses in dermatology, especially as a tissue repair agent. In addition, in the patent application PCT / FR96 / 01051, the Applicant has already described the use of gamma-aminobutyric acid in combination with an α-hydroxylated acid and a plant extract. As depigmenting agent, this mention is very succinct and does not provide any details on the reality of this action. It is not the subject of claims.

The prior art can be illustrated by a number of references citing γ-amino-butyric acid associated with a surfactant to ensure transcutaneous passage. Patent JP09 / 659142 (Kanebo) shows that it is an associatioin constituted by pantethein - S.sulphonic acid (or a salt thereof), di-isopropylamine dichloroacetate and γ-acid. butyric amine or a derivative thereof and a nonionic surfactant having an HLB of the order of 16, for example polyoxyethylene (20) sorbitan mono oleate. The concentration of surfactant in the mixture is high (1-10) and is intended to improve percutaneous absorption of ingredient A to promote the rate of passage into the stratum corneum of the skin.

The presence of a nonionic surfactant suggests that the action of the suppressive agent for the production of melanin-type pigments depends on the transcutaneous absorption of the active ingredient.

The γ-aminobutyric acid, one of its salts or one of its esters acts by itself, obtaining by simple application a significant reduction of the intracellular content in melanin of the cells.

It appears that the present invention relates to different compositions, acting by a different mechanism producing different effects.

The prior art also discloses another Japanese patent application (10194960) Kanebo. As is apparent from the summary in English, it is a cosmetic composition for the skin with photoprotective properties (preventing the skin from getting dark, making dark skin light rapidly ...). It is a preparation whose composition is distinctly different:

From 0.001 to 5% by weight of at least one type of product promoting blood circulation (such as γ-aminobutyric acid, etc.) and preferably an agent derived from a decomposition agent, of an enzymatic nature obtained by treating an extract derived from rice or rice seed coat with an enzyme such as actinase, pepsin or trypsin and extracting with a neutral solvent such as purified water.

The nature of the rice extract treated with such an enzyme and exhausted with water is not known. It may be thought that the active agent is a mixture of traffic promoting agents or a cell activator and an enzyme decomposer (breaking down enzyme) from rice. This is also a preparation of very different composition probably acting by changing the blood circulation.

The literature still quotes the reference Gudzenko janna Prokovievna USP 5,817,621. It is certain that this reference mentions column 3 the use of Gabaergic substances and in particular the use of L-Dopa and GABA simultaneously.

However, the compositions whose details are provided do not concern the use of GABA-ergic substances such as γ-amino butyric acid but of a complex mixture of vitamin A, salicylic acid,

Camphor, a GAB-ergic substance, a dopaminergic substance, a cholinolytic substance (atropine), pancreatin, ascorbic acid, pantothenic acid in the form of calcium salt and vitamin B 12.

Such a preparation exhibits trophic properties and in particular restores the physiological functionalities of the skin by acting on the gaba-ergic neurons. This patent states (column 3 line 53) ... skin pigmentation becomes normal, the skin becomes rosy and flesh-colored. There is no question of depigmentation or re-pigmentation.

The reference YU (US Pat. No. 7,667,924 B2) constitutes a reference from the previous literature insofar as it mentions aqueous or oily compositions (column 3 lines 37-39 and claim 4).

This concerns only very little the present invention since the passage quoted column 3 mentions the use of compositions in different skin pathologies such spots, lentigine, melasma, ... blemished skin, hyperpigmented skin ...

This means that the compositions described in the cited YU patent are suitable for any type of pigmentation disorder both for skin blemished skin and for hyper pigmentation of the skin.

It is important to specify that the compositions described in reference YU are a mixture of amphoteric or pseudoamphoteric surfactant and of a polyhydroxylated alpha hydroxyl acid.

The hydroxyl acid solutions are very acidic and the amphoteric agent intervenes to neutralize the high acidity and make it compatible with the skin. This means that the γ-amino-butyric acid cited in this literature reference has only a neutralizing power and can not be considered as an active ingredient.

It has also been determined that this acid finds remarkable use as a depigmenting agent in comparison with conventional conventional agents such as hydroquinone derivatives (arbutin) or kojic acid, while being less cytotoxic.

Gamma-aminobutyric acid and its salts and derivatives, used in such compositions has been studied on isolated cells and in particular on normal human melanocyte cultures. On the experimental models used, it exhibits an inhibitory action on tyrosinase and leads to a clear decrease in the synthesis of melanin. In particular, there is a significant reduction in the intracellular melanin content of cells in culture. The results obtained depend on the dose, which favors a specific effect of gamma-aminobutyric acid on this type of parameter.

The compositions according to the invention contain as active principle gamma-aminobutyric acid as such or in the form of a salt with a mineral or organic acid, physiologically compatible or in the form of lower alkyl ester or polyol.

Among the salts of gamma-aminobutyric acid that may be used, mention may be made of hydrochloride, sulphate, phosphate, acetate, propionate, citrate, tartrate, benzoate, pidolate, glucose-phosphate and methane sulphonate. or p-toluene sulfonate.

The gamma-aminobutyric acid esters which may be used in the practice of the invention may be a methyl, ethyl, propyl, butyl or hexyl ester, or a polyethylene glycol ester, a polybutylene glycol ester or else a sugar or polyol ester such as mannitol, sorbitol or glycerol.

As needed, these esters will be soluble in water or soluble in organic solvents such as oils. Their choice will be determined by nature of the cosmetic composition in which they are incorporated as active principle.

The compositions according to the invention may contain other active ingredients such as plant extracts rich in polyphenols or tannins, such as white mulberry extract or α-hydroxylated acids such as lactic acid, or fruit extracts. like lemon or grapefruit extracts, also rich in alpha-hydroxy acids.

The compositions based on gamma-aminobutyric acid may be supplemented with thickening agents, gelling agents, emulsifying agents, perfuming agents, stabilizing agents, preserving agents, agents improving the touch or the fluidity.

In this respect, mention may be made, as an emulsifying agent, of polyethylene glycol stearate or esters of sugars, such as sucrose ester.

Thickening agents that may be mentioned include cellulose derivatives such as methylcellulose, ethylcellulose, β-hydroxyethylcellulose, carboxymethylcellulose or crosslinked carboxymethylcellulose such as Acdisol®.

A gelling agent will for example be a polymer of acrylic acid or acrylamide, such as the carbomers sold under the name Carbopol® (Goodrich).

The concentration of gamma-aminobutyric acid in the compositions may vary from 0.4 to 10% of the total composition with a preference for 0.5 to 5%.

The following examples illustrate the invention without limiting it.

Example 1 Cream based on gamma-aminobutyric acid hydrochloride

Gamma-aminobutyric acid hydrochloride 7.5 g

White mulberry extract 0.5 g BG lemon extract 2.0 g

Lanette® wax 3.75 g

Emulsifying agent 0.5 g

Water qs 100 g Example 2 Gamma-Aminobutyric Acid-Based Gel

Gamma-aminobutyric acid 2 g

Propylene glycol 5 g Sweet almond oil 10 g

0.1 g silicone oil

Germaben II 0.02 g

Carbopol® 936 0.4 g

Triethanolamine 0.1 g Floral scent qs

Purified water 80 g

Example 3 Study of the Toxicity of Gamma-Aminobutyric Acid-Based Compositions The objective of this study was to evaluate the cytotoxicity of gamma-aminobutyric acid, white mulberry extract and lemon extract taken separately from that of a well-known α-hydroxy acid. as lactic acid (compound E).

The determination is made on normal human melanocytes obtained from a young subject (4 years). For the experiments carried out, the cells were cultured until confluent mono-layers were obtained.

Incubation of the cells: The cells were incubated for 72 hours in the absence (control test) or in the presence of increasing concentrations of compound E or each of the products tested. For compound E, concentrations of 0.003 were tested; 0.03; 0.075; 0.15; 0.5; 0.75; 1.5 and 3% (v / v) and for the product according to the invention: 0.01; 0.1; 0.25; 0.5; 1; 2.5; 5; 10% (v / v).

The test product was prepared by directly diluting gamma-aminobutyric acid in ultrapure water, in a quantity sufficient for 100% (v / v).

For comparison, a 10% solution of kojic acid and a 30% lactic acid solution (composition E) were prepared. The tested preparations were then diluted directly in the melanocyte incubation medium.

Evaluation of the effects: At the end of the incubation period, the viability of the cells was evaluated by a spectrophotometric method for the determination of the intracellular phosphatase activity.

According to the method of Yan T. et al. (Anal Biochem 24 (1996) 103-108), the p-nitrophenol resulting from the transformation of p-nitrophenyl phosphate by intracellular phosphatases of viable cells is assayed. The absorbance of p-nitrophenol released at 405 nm is directly proportional to the number of viable cells present in the culture well.

Results:

The lactic acid (composition E) after 72 hours of incubation, significantly reduces the number of viable melanocytes present in the culture wells. This effect is detectable (less than 80% of viable cells still present in the culture well) at a dose of 0.03%. Lactic acid is clearly cytotoxic.

Gamma-aminobutyric acid shows a cytotoxic effect detectable under the same conditions as from the dose of 0.5%. Consequently, the depigmenting composition according to the invention containing 10% gamma-aminobutyric acid exhibits a cytotoxic effect only at higher experimental doses (see FIGS. I, II and III and Table I).

Table I

Study of the cytotoxicity of lactic acid (E) and the composition based on gamma-aminobutyric acid

Active E

Composition

Compositions based on white mulberry extract or lemon extract also have moderate effects.

EXAMPLE 4 Effect "Melano-modulator" of the active principles contained in the compositions according to the invention The search for a melanomodulatory effect was conducted in two steps:

- Melanomodulatory effect of ingredients taken separately at predetermined concentrations in the cytotoxicity test. - Melanomodulatory effect of the complex, i.e. GABA in combination with white mulberry, lemon and lactic acid ingredients.

the ^st stage These tests were conducted on a model of normal human melanocytes grown in single layer.

Gamma-aminobutyric acid, lemon extract and white mulberry extract were solubilized and diluted directly in the culture medium.

Incubation of the cells with the products tested:

Normal human melanocytes were incubated for 72 hours in the absence (control) or in the presence of a reference product (250 μM kojic acid) or increasing concentrations of the active products tested.

Gamma-aminobutyric acid (composition A) 0.001; 0.01; 0.1% White mulberry extract (Composition C) 0.01; 0.1; 0.5% Lemon extract (Composition D) 0.01; 0.1; 1%

In this method, the melanin / protein ratio is measured as a percentage of the control. The values obtained with the solvent alone and a solution of 250 μM kojic acid in this solvent (DMSO) taken as a reference substance were also determined.

Table II gives the results obtained on the separated active ingredients A (gamma-aminobutyric acid), C, D and lactic acid (composition E). Gamma-aminobutyric acid provides statistically significant results at a concentration of 0.1%. Compounds C and D have a moderate melanomodulatory effect.

2nd step

The effect of a complex containing the active ingredients A (gamma-aminobutyric acid), C, D and lactic acid (composition E) was also evaluated as a comparison element on melanin synthesis in a model of human melanocytes. normal grown in monolayer. Table II

Vehicle O) MSO) and reference product

*. : mean significantly different from control group "medium only" (p <0.05)

Assets tested

: mean significantly different from control group "middle only" (p <0.05)

A: Composition based on gamma-aminobutyric acid C: Composition based on white mulberry D: Composition based on lemon extract

Products to test:

The compositions were prepared by directly diluting gamma-aminobutyric acid A, principles C and D and lactic acid (compound E) in ultrapure water at the following concentrations: gamma-aminobutyric acid 10% -extract of white mulberry 1% -extract of lemon 1% -lactic acid 1.5% -water ultra pure

The compositions under test were then diluted directly in the melanocyte incubation medium at concentrations of 0.1; 0.5; and 1% (v / v).

Test system:

Normal human melanocytes from a 4 year old young subject were used. They were grown in monolayer up to 80% confluence.

Reference product:

As a reference tyrosinase inhibitor, kojic acid has been used as a

250 _μ M. Incubation of the cells:

The melanocytes were incubated for 72 hours at 37 ° C in a humid atmosphere and 5% CO = in the absence (control) or in the presence of kojic acid or increasing concentrations of active ingredients under test ( 0.1; 0.5; l%)

Evaluation of anti-melanin effects: 1. Determination of melanin:

At the end of the incubation period, the intracellular content of melanin was quantified after cell lysis by spectrophotometric measurement at 405 nm.

2. Protein assay:

At the end of the incubation period, the proteins contained in the cell lysates were assayed by a spectrocolorimetric method using Coomassie blue (according to the method of Bradford M. Anal., Biochem 72 (1976) 248-254). .

3. Results: The results are given in the form of a percentage of melanin relative to the controls (average + or standard deviation SD) calculated from values obtained in μg of intracellular melanin per mg of total proteins of the cell layer.

The statistical significance of the differences between the "control" and "test product" conditions was determined by a single-factor analysis of variance (ANOVA) followed by a Holm-Sidak test (* = μ < 0.05)

The results obtained with the composition based on gamma-aminobutyric acid show a significant reduction in the intracellular content of melanin cells in culture.

The value obtained with 0.1% of active ingredient is not significant. The values obtained with a concentration at 0.5% (-19.7%) and at 1% (-25.4%) are statistically significant (p <0.05). These results are shown in Figure 3 and Table III. The 250 μM kojic acid used as reference melanogenesis inhibitor, for comparison, produced a significant decrease in the intracellular melanin content of cells cultured (15.5% reduction) (p <0.05).

This result shown in Table III provides proof of the validity of the investigation method.

The results obtained with the gamma-aminobutyric acid compositions are dose-dependent, which favors a specific effect of the complex on the studied parameter.

Results

The results presented in Figure 4 and Table III below show that under the experimental conditions selected:

The test complex significantly reduces the intracellular content of melanin cells in culture: Complex at 0, 1% (v / v)> - 14, 1% (ns)

Complex at 0.5% (v / v)> - 19.7% (p <0.05)

Complex at 1% (v / v)> - 25.4% (p <0.05)

Table III

Complexes on trial

* mean average Reference product: kojic acid 250 μM

*: mean significantly different from the control group "medium alone" (p <0.05)

Gamma-aminobutyric acid or its salts with an inorganic or organic acid or its derivatives is used in the form of aqueous or oily cosmetic compositions chosen from milks, lotions, oil-in-water or water-in-oil emulsions, creams, gels and toilet waters.

The concentration of gamma-aminobutyric acid may vary widely from 0.4 to 10% by weight of the total composition. A more preferred concentration ranges from 0.5 to 5% by weight.

When gamma-aminobutyric acid is used as a salt or a derivative, the amounts used should take into account the content of gamma-aminobutyric acid in the salt or derivative. In the case of polyphenol ester, the gamma-aminobutyric acid concentrations must be calculated to achieve an active ingredient content ranging from 0.4 to 10% by weight in the cosmetic compositions of the invention.

Claims

REVENDICATIQNS

1. Use of gamma-aminobutyric acid, a lower alkyl salt or ester thereof or polyol as depigmenting agent or melano modulator.

2. Use according to claim 1 wherein the free gamma-aminobutyric acid is used as depigmenting agent or melano-modulator.

3. Use according to claim 1 wherein a gamma-aminobutyric acid salt is used as depigmenting agent or melano-modulator.

The use of claim 1 wherein the gamma-aminobutyric acid salt is a salt with a physiologically compatible mineral or organic acid.

5. Use according to claim 1 or claim 4 wherein the gamma-aminobutyric acid salt is gamma-aminobutyric acid hydrochloride.

6. Use according to claim 1 wherein a lower alkyl ester of gamma-aminobutyric acid is used as depigmenting agent or melano-modulator.

7. Use according to claim 1 and claim 6 wherein the lower alkyl ester is a lower alkyl ester of gamma-aminobutyric acid soluble in water or soluble in organic solvents.

8. Use according to claim 1 wherein gamma-aminobutyric acid is supplemented with a plant extract rich in polyphenols or tannins, as depigmenting agent or melanomodulator.

9. Use of gamma-aminobutyric acid, its salts or its lower alkyl esters or polyol in topical cosmetic compositions.

10. Use of gamma-aminobutyric acid according to claim 9 in aqueous or oily compositions chosen from milks, lotions, oil-in-water or water-in-oil emulsions, creams, gels and waters. toilet.

11. Use of gamma-aminobutyric acid, a salt or an ester thereof according to claim 1 in cosmetic compositions at a concentration ranging from 0.4% to 10%.

12. The use of gamma aminobutyric acid according to claim 1 at a concentration ranging from 0.5% to 5% as a depigmenting agent.