WO2007003768A2

WO2007003768A2 - Use of an extract of the species trigonella foenum graecum in a cosmetic or pharmaceutical composition

Info

Publication number: WO2007003768A2
Application number: PCT/FR2006/001522
Authority: WO
Inventors: Claude Dal Farra; Nouha Domloge; Dominique Peyronel
Original assignee: Societe D'extraction Des Principes Actifs Sa (Vincience)
Priority date: 2005-07-01
Filing date: 2006-06-29
Publication date: 2007-01-11
Also published as: FR2887773B1; FR2887773A1; WO2007003768A3

Abstract

The invention relates to the use of at least one isoleucine, monohydroxlated or polyhydroxylated amino acid, and/or one of the derivatives thereof, as an active agent for inducing the endogenous synthesis of the SIRT proteins in skin cells, in or for the preparation of a cosmetic or pharmaceutical composition.

Description

USE OF AN AMINO ACID AS AN ACTIVE AGENT INDUCING THE SYNTHESIS OF SIRT PROTEINS IN SKIN CELLS.

The invention relates to the field of cosmetics and pharmaceuticals, particularly the field of dermatology. The subject of the present invention is the use of at least one isoleucine amino acid, mono or polyhydroxylated, and / or one of these derivatives as an active agent inducing the endogenous synthesis of SIRT proteins in the cells of the skin, in or for the preparation of a cosmetic or pharmaceutical composition.

SIRT proteins are part of the Sirtuine family, they are nuclear proteins, NAD + dependent, playing an important role in the deacetylation of histones. SIR (Silent Information Regulators) genes, encoding SIR proteins, were first described in S. cerevisiae in 1979 (Rine J and AL, Genetics 1979). Later, it was shown that overexpression of the SIR2P protein in C. elegans increased the lifespan of this organism (Tissenbaum and AL, Nature 2001), suggesting that these proteins are related to longevity. .

SIRT1 protein is the most well-characterized human sirtuin, interacting with many transcriptional regulators. The human SIRT1 protein has been described as being involved in the regulation of p53 (Cheng HL et al. Proc Natl Acad Sci U S A. 2003); and, more recently, as a modulator of cellular senescence (Langley E and AL, EMBO J. 2002). Other human SIRT proteins have been discovered (SIRT2, SIRT3, SIRT4-7). The human protein SIRT2 has been little studied, but some studies have demonstrated its role in the control of mitotic activity (Dryden SC and AL, Mol CeIl Biol 2003) and its involvement in the regulation of the p53 protein (Vaziri H and AL, CeIl 2001). To date, histone deacetylases are considered to be an enzyme family that plays an important role in the regulation of cell cycle and death (Porcu M. and Chiarugi, Trends Pharmacol ScL, 2005).

Several studies in organisms as diverse as C. elegans or mammals have shown that there is a relationship between energy intake and shelf life and that the SIRT protein is responsible for this coupling. Thus a reduction in caloric intake increases the lifespan of yeast {Tissenbaum et Al, Nature, 2001). In addition, recent studies have shown that SIRT1 causes fat mobilization in adipocytes (Picard F. et al, Nature, 2004). SIRT proteins are currently considered as potential therapeutic targets for treating dysfunctions or diseases related, inter alia, to obesity, diabetes or hyperlipidemia (WO 03/061681, US 2005/0164969).

SIRT proteins have recently been shown to be significantly expressed in the skin and play a very important role. Indeed the SIRT protein, specifically the protein SIRTl ₅ is present in skin cells and that its expression is altered by various stresses that affect the skin cells. In particular, it has been demonstrated that the induction of the expression of this protein by different agents makes it possible to protect the cells and better help them to fight against stress and intrinsic aging.

SIRT1 protein has a very important function in aging and cellular protection. Thus, an increase in its expression allows the skin to better withstand external aggressions. More generally, the induction of the expression of this protein in the cells of the skin makes the cell protection mechanisms more efficient and would increase the cell life.

The presence of this protein in the skin, as well as the benefits of its overexpression, offers the prospect of new modes of action and new ways to improve cell survival, including cell survival of skin cells; but also, more generally, means of improving the properties of the skin. By improving the properties of the skin means any means intended to maintain or restore a good functioning of the skin or any means that serves to preserve or improve its appearance and / or appearance.

Thus, an increase in the synthesis of SIRT proteins will enable the skin to prevent the skin manifestations of aging, to be better protected against external aggressions and against the stresses to which it is subjected. Moreover, and according to a more global view of the invention, an induction of SIRT will have anti-inflammatory and anti-irritant effects as well as a positive action on tissue regeneration and healing by an action, for example , on the increase of the synthesis of proteins constituting the extracellular matrix. The present invention thus relates to the use of an effective amount of at least one mono or polyhydroxylated isoleucine amino acid, and / or of one of these derivatives, as active agent inducing the endogenous synthesis of SIRT proteins in skin cells. This active agent may be used alone or in combination with at least one other active agent, in or for the preparation of a cosmetic and / or dermopharmaceutical and / or dermatological composition.

In fact, by virtue of their inducing activity for the synthesis of SIRT proteins, these particular amino acids have specific biological activities which make them directly usable in cosmetic, dermatological or pharmaceutical preparations or compositions.

The use of at least one isoleucine amino acid, mono or polyhydroxylated, and / or one of these derivatives, in the cosmetic and pharmaceutical fields, is known, in particular with regard to skin care, as described in the patent. FR 2 852 841. However, its use as an activating agent for the synthesis of SIRT proteins has not yet been explained.

To date, very few uses of protein synthesis inducing agents of the SIRT family in skin cells have been described. Among these agents capable of activating the synthesis of SIRT proteins of the skin, mention may be made of various molecules including, for example, polyphenols. More particularly, mention may be made of: trans-stilbene derivatives (resveratrol, piceatannol), chalcone derivatives (isoliquiritigenine, butene), flavone derivatives (fisteine, luteoline, quercetin).

Thus, the main object of the present invention relates to the use of a new active agent capable of inducing the synthesis of SIRT proteins. The invention relates to the use of an effective amount of at least one mono or polyhydroxylated isoleucine amino acid and / or one of these derivatives as an active agent inducing the endogenous synthesis of SIRT proteins in the cells of the skin, in or for the preparation of a cosmetic or pharmaceutical composition. Preferably, according to the invention, the compounds will activate a particular class of SIRT proteins, SIRT1 proteins.

By active agent is meant an active agent capable of inducing or activating the synthesis of SIRT proteins in the cells of the skin. That is to say, able to increase the quantity of these proteins in the cells, but more particularly, one essentially hears designate all the active agents likely to favor the endogenous production of SIRT proteins; and most particularly the molecules involved in the positive control of precursors such as DNA or RNA.

The active agent can be defined as being a molecule or a set of molecules capable of modifying or modulating the functioning of a biological system.

According to an advantageous embodiment of the invention, the amino acid is 4-hydroxyisoleucine of formula:

CH ₃ - CH - CH - CH - COOH

I I I

OH CH ₃ NH ₂

Furthermore, the active agents according to the invention relate to isoleucine derivatives and 4-hydroxyisoleucine derivatives. By "isoleucine derivatives" is meant both these chemical derivatives and these biological derivatives. By "derivative" is meant all leucine or isoleucine amino acid derivatives to which a moiety would have been added. This group is likely to bring better properties to the active agent defined according to the invention. Thus, for example, the groups may be added in order to facilitate better penetration into the skin, these derivatives being, for example, "oleyl", "stearyl" or "palmityl" type radicals.

In addition, for example, it is possible, for reasons of resistance or efficiency, that the amino acid is modified on its carboxylic acid functions and / or on its amine functions. Thus, according to another aspect of the invention, the amino acids according to the invention can be modified by acylation or acetylation on their amine function, and / or they can be modified by amidation or esterification on their carboxylic function. Furthermore, according to a particular embodiment of the invention, the amino acids may be in the form of lactone.

The amino acids according to the present invention may be in any existing isomeric forms. However, 4-hydroxyisoleucine is preferably used in the form of its isomers (2S, 3R, 4S) and / or (2R, 3R, 4S). These particular isomers are the isomers that are obtained mainly from the process for obtaining the 4-hydroxyisoleucine used to obtain the active agent according to the invention. More particularly according to the invention, the 4-hydroxyisoleucine is in the form of the (2S, 3R, 4S) isomer. According to a preferred embodiment of the invention, the active agent is of plant origin.

Preferably, the active agent according to the invention is obtained from plants belonging to the genus Trigonella. Of course, the amino acid can be obtained from at least one of the many varieties and species belonging to the genus Trigonella.

More particularly, the active substance is obtained from at least one plant of the species Trigonella foenum graecum, commonly called fenugreek. Fenugreek is an annual herbaceous plant, it belongs to the sub-order of legumes, to the family of

Papilionaceae and the genus Trigonella. It is a plant grown mainly in the Mediterranean regions and known since antiquity for its therapeutic virtues.

This plant has the particularity of having a high content of protein material in the seed and especially to have a particular free amino acid, hydroxisoleucine. This amino acid was identified for the first time in 1973 by Fowden et al., It accounts for more than 60% of the free amino acids present in the seed. Hydroxyisoleucine is also present but in smaller amounts in the leaves and stems of fenugreek.

Thus, according to a preferred embodiment of the invention, the active agents will be extracted from germinated seeds of plants of the genus Trigonella, and more particularly from seeds of the plant of the species Trigonella foenum graecum.

It should be noted that 4-hydroxyisoleucine is also present in some other plant species; thus Raffauf et al. (1984) showed the presence of this particular amino acid in Quararibeafunebris, a tree of the Bombacaceae family. The presence of 4-hydroxyisoleucine has also been reported in species such as Lactarius camphoratus (Dardenne et al., 1986), Dioscorea deltoidea and Balanites aegyptia.

(Hardman and Abu-Al-Futuh, 1976). It is understood that the active agent according to the invention, in particular 4-hydroxyisoleucine, can be obtained from any of the plant species containing it.

The amino acids, subject of this patent, can be obtained either by conventional chemical synthesis, or by extraction or purification from natural or synthetic substance. Preferably according to the invention, the active agent is obtained by extraction and / or purification from a natural raw material, in particular plant material. Any method of extraction or purification known to those skilled in the art can be used to prepare the active agent according to the invention. To extract the 4-hydroxyisoleucine from the fenugreek, use, for example, the method described by Hardman and Abu-Al-Futuh (Planta Medica, 36, 79-80, 1979) or any other method of amino acid extraction known to those skilled in the art.

Thus, one can in a first step, grind the seeds, using a plant grinder for example. According to a variant of the method of the invention, it is possible to use seeds during germination, or to use only part of the seed containing the embryo and / or the cotyledons. The fenugreek seeds are then "delipidated" by extraction of the fatty substances with conventional organic solvents for this purpose, such as, for example, hexane, chloroform, an alcohol or acetone. An apolar or low polarity solvent is preferably used, for example hexane. The extract is then evaporated.

The extraction itself is carried out with stirring, at a temperature of between 4 and 100 ^° C., in an aqueous solution, that is to say composed of water, or with a solution comprising a mixture of water and water. an organic solvent miscible with water, preferably an alcohol (methanol, ethanol or isopropanol). The proportion of water in the mixture may vary between 10 and 50%. Preferably, the hydroalcoholic mixture will contain 70 to 80% of ethanol. The extraction can be carried out at a pH of between 4 and 10, but it is preferable to work at a pH of between 5 and 6 to prevent degradation of the 4-hydroxyisoleucine.

The hydroalcoholic extract is a first usable form of the extract containing the active agent. A step of evaporation of the alcohol can easily be considered. The soluble fraction is subsequently recovered by centrifugation and filtration. In another step, the extract obtained can be further purified by fractionation, in particular by a conventional method of ion exchange resin chromatography, as for example by the Moore technique, Syein and Spackman (1958). Moreover, after the extraction step, it is possible to subject the extract to a purification treatment in order to reduce the amount of undesirable compounds, such as, for example, the compounds responsible for the odor or the color. of the product. This treatment may consist in bringing our solution into contact with various absorbents such as activated carbon, bleaching earth or silica; then, subsequently, to perform a filtration step. 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. It is thus possible to easily obtain an extract containing 4-hydroxyisoleucine to a high degree Purity It is thus possible to easily obtain an extract containing 4-hydroxyisoleucine to a very high degree of purity (10 to 40%).

The use of the active agent according to the invention, capable of activating the synthesis of SIRT1 proteins in the cells of the skin, will preferably be in the form of a composition suitable for external topical administration, mainly on skin, mucous membranes and / or integuments, comprising a cosmetically or dermatologically acceptable medium.

The effective amount of active agent is the amount needed to achieve the desired result. Thus, according to an advantageous embodiment of the invention, the active agent mentioned above is used, in the compositions, at a concentration of between 0.00001% and

About 20%, and preferably at a concentration of between 0.001% and 10% by weight relative to the total weight of the final composition.

Said active agents according to the invention are also advantageously used in order to fight in a curative and / or preventive manner against the manifestations of skin aging, but also in order to improve the appearance of the skin and / or integuments. By the care of the skin and / or integuments, we mean all the actions intended to maintain or restore a good functioning of the skin and / or superficial body growths or any means which serves to preserve or improve their appearance and / or their appearance. So the care includes hydration, soothing, protection against all types of aggression, including sun protection, fight and prevention of the manifestations of aging. By cutaneous manifestations of aging is meant any changes in the external appearance of the skin due to aging, such as, for example, wrinkles and fine lines, wilted skin, soft skin, thinned skin, lack of elasticity and / or skin tone, dull and lackluster skin but also any internal changes in the skin that do not systematically result in a modified external appearance such as, for example, all internal skin damage resulting from exposure to ultraviolet radiation. The term "improve the appearance of the skin" means all phenomena that are likely to result in a visual improvement of the condition of the skin. The skin will look better; it will be, for example, much more beautiful, firm and / or smooth. All small imperfections will be diminished or removed. The papery appearance of the skin will, for example, be attenuated. In addition, the active agent according to the invention, or the composition containing it, may be intended to protect keratin substrates, and more particularly to protect the skin and / or integuments against all types of external aggression. The use of these active agents or compositions containing them, will allow the keratin substrates to be protected and better withstand the stress that produces on them the environment. The term "external aggression" is understood to mean the aggressions that the environment can produce. These attacks can be of chemical, physical, biological or thermal origin.

In another aspect, the active agents according to the invention will advantageously be used to reduce and / or prevent inflammatory and / or skin irritant reactions. Indeed, the active agents according to the invention, intended to activate the endogenous synthesis of SIRT proteins, and more particularly SIRT1 proteins, have anti-inflammatory and anti-irritant effects. The use of the properties of these assets therefore makes it possible to have a skin that is more protected and much less sensitive to the various aggressions that it may encounter. The skin is soothed. Moreover, the active agents according to the invention as defined above, stimulate the metabolic functioning of the cells of the skin. They thus make it possible to increase the synthesis of proteins essential to its functioning, in particular by increasing the synthesis of proteins constituting the extracellular matrix. The active agents according to the invention, or the composition containing them, thus have a positive action on tissue regeneration. The active agents according to the invention are particularly effective in treating cicatrization disorders.

These active agents, capable of activating the endogenous synthesis of SIRT proteins, may be used, more generally, to treat dermatological conditions. Dermatological conditions are all diseases affecting the skin and having or not visible consequences. As such, there may be mentioned, for example: disorders related to cell differentiation and proliferation problems, problems related to keratinization, inflammatory or allergic disorders, disorders related to sebaceous functions, dermal or epidermal proliferations (benign or malignant); cutaneous disorders due to U.V radiation exposure, pathologies associated with chronological or actinic aging.

Thus according to another aspect, the active agents according to the invention, as described above, intended to activate the endogenous synthesis of SIRT proteins in the skin cells, may be used for the manufacture of a medicament for the treatment of dermal conditions.

According to another aspect, the subject of the present invention is the use of active agents according to the invention, intended to activate the endogenous synthesis of SIRT proteins in skin cells, alone or in combination with at least one other active agent. , to produce a localized thinning effect after application to the skin, and more particularly to reduce, eliminate or prevent subcutaneous fat overloads.

Hypodermic adipose tissue is the largest energy reservoir in the body. If an imbalance settles in the body between the processes of lipogenesis and lipolysis, the volume and the number of the adipocytes can increase; hypertrophy and adipocyte hyperplasia, which can be accompanied by hyperviscosity of the substance and a slowing of the venous and lymphatic circulation. It is called cellulite, which is manifested by an overload of adipose tissue, especially in women, at the hips, thighs, buttocks, knees and forearms. The skin has a quilted and padded appearance and at the most advanced stage the appearance of "orange peel", which is characterized by a succession of depressions caused by excessive stretching of the connective bays and the attraction of the epidermis to the tissues deep.

According to an advantageous embodiment of the invention, the aforesaid active agent is previously solubilized in one or more cosmetically or pharmaceutically acceptable solvents such as water, glycerol, ethanol, propanol or isopropanol, propylene glycol, butylene glycol , dipropylene glycol, ethoxylated or propoxylated diglycols or any mixture of these solvents.

According to yet another advantageous embodiment of the invention, the aforesaid active agent is previously 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.

Whatever the form of the invention, the composition according to the invention can be ingested, injected or applied to the skin (on any cutaneous area of the body), hair, nails or mucous membranes. Depending on the method of administration, the composition according to the invention can be in any of the galenical forms normally used. Preferably, the compositions according to the present invention will be in a dosage form suitable for topical administration to the skin. They cover all cosmetic or dermatological forms. These compositions must therefore contain a cosmetically acceptable medium, that is to say, compatible with the skin, hair or hair.

According to another aspect, the present invention relates to a cosmetic treatment method for skin care intended to increase the endogenous synthesis of SIRT proteins in the cells of the skin, characterized in that a composition is applied to the skin. containing the active agent as defined above, in order to obtain the desired action.

Particular embodiments of this cosmetic treatment method also result from the foregoing description. The cosmetic treatment method of the invention may be implemented in particular by applying the cosmetic compositions as defined above, according to the usual technique of use of these compositions, for example: application of creams, gels, serums , lotions, milks, shampoos or sunscreen compositions, on the skin or on the hair, or application of toothpaste on the gums.

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 4-hydroxyisoleucine

A quantity of 100 grams of germinated seeds of the plant of the species Trigonella foenum graecum is ground in a knife mill, with a grain size of 200mm. The ground material is then delipidated with hexane. Extraction is carried out at room temperature by an acidic aqueous-alcoholic solution at pH 5 composed of an acetate buffer containing 0.1% of ascorbic acid and 80% of alcohol. The medium is then clarified by centrifugation. These two operations are repeated three times. The three clarified fractions are then combined and filtered on a plate filter. The extract containing free amino acids, and more particularly 4-hydroxyisoleucine, is then purified by passage over a column containing a cation exchange resin so as to retain the amino acid 4-hydroxyisoleucine. The elution is carried out in a basic medium, for example using an ammonia solution. The extract is then subjected to a purification treatment using an activated carbon. The extract thus obtained contains 10 to 40% of 4-hydroxyisoleucine by weight of the dry extract.

EXAMPLE 2 Demonstration of the Effect of the Extract According to Example 1 on Fibroblasts

The aim of the study is to determine the influence of the extract according to Example 1 on the synthesis of SIRT1 proteins by fibroblasts, by the immunofluorescence technique and by the Western-blot technique. Immunofluorescence and Western blot techniques are semi-quantitative techniques that can be used to assess the level of proteins present in cells.

Human fibroblasts are maintained in culture at 37 ° C in a humidified atmosphere containing 5% CO ₂ . For immunofluorescence studies, fibroblasts were grown on 8-well slides; for the western blot, the cells were grown in boxes 100 mm in diameter. The cells are then incubated for 24 or 48 hours with the extract according to Example 1 dissolved in 0.5% or 1%; a control condition containing no extract is carried out.

Immunofluorescence Studies After removing the supernatants and rinsing the cultures, the cells are fixed with methanol for 4 minutes at 4 ° C. and then rinsed with PBS buffer. Anti-human SIRT1 rabbit antibodies, diluted 1/100, are then added (Santa Cruz Biotechnology). The incubation lasts 3 hours at room temperature; the supernatants are then removed and the cells are rinsed with PBS. Then a secondary antibody (anti-rabbit, Molecular Probes), coupled to a fluorescent marker (Alexa 488) is added. After 1 hour of incubation at room temperature, the supernatants are removed and the cells are rinsed with PBS. The slides are then mounted and examined under an Epi-fluorescence microscope (Nikon Eclipse E600 microscope). The amount of SIRT1 proteins, synthesized by the cells, is proportional to the intensity of the fluorescence. The results thus obtained demonstrate a significant increase in the expression of SIRT1 proteins at the nucleus of the cell after application of the extract according to Example 1 for 24 and 48 hours. Furthermore, the higher the concentration of extract applied at the cell level, the higher the intensity.

Western-blot studies

The cells are washed and harvested in extraction buffer (20mM Tris, 15OmM NaCl, 10mM EDTA, 0.2% Triton X100) enriched with a protease inhibitor cocktail (Sigma). The proteins thus extracted are centrifuged at 4 ° C. at 10,000 rpm for 10 minutes and the samples thus obtained are stored at -80 ° C.

After standardizing the samples according to their protein loading (BCA protein assay kit, Pierce), the cell lysates are electrophoretically separated on a 4-12% NuPAGE gel (Invitrogen) and transferred to a nitrocellulose membrane (PAL corporation). The membranes are incubated overnight with an anti-human SIRT1 rabbit antibody (Santa Cruz Biotechnology), diluted to 1/200, followed by incubation with an anti-rabbit IgG-peroxidase antibody, diluted to 1/5000, (Beckman Coulter). The revelation is carried out with a chemiluminescent substrate.

In order to assay the SIRT1 proteins present in the cells, the luminescent signals emitted by the isolated bands present in the gel are quantified using Chimilmager software (Alpha Innotech Corporation, USA).

The quantity of proteins is expressed as a percentage of light intensity, compared to the control condition, that is to say compared to the cells which did not receive the extract according to Example 1.

The results presented in the table above show that when the cells are incubated in the presence of the extract according to Example 1, an increase is observed. significant intensity of light intensity, after 24 and 48 hours of treatment compared to untreated cells. The results allow to conclude that the addition of the extract according to Example 1 in the fibroblast culture medium has the effect of increasing the synthesis of SIRT1 proteins by the cells, in a presumably dose-dependent manner.

EXAMPLE 3 Ex Vivo Detection of the Effect According to the Extract According to Example 1

Ex vivo immunolabeling studies have demonstrated the expression of SIRT1 proteins on skin samples. Human skin samples are cultured at the air / liquid interface. The extract according to Example 1 is applied topically to these samples at the level of the epithelium, then the samples are incubated for 24 hours.

These skin samples are then fixed with formaldehyde and then embedded in paraffin. Sections 2 to 3 μm thick are then made. Immunostaining is performed after several dewaxing and unmasking steps of the antigenic sites. Immunolabeling itself was performed with a human anti-human SIRT1 rabbit polyclonal antibody (IBL Co), diluted 1:50, and then with a secondary antibody (anti-rabbit, Molecular Probes), coupled to a fluorescent marker. The results obtained demonstrate that the skins treated with the extract according to Example 1 express a significantly higher amount of SIRT1 proteins than untreated skins. Thus, the extract according to Example 1 makes it possible, at the cutaneous level, to increase the expression of the SIRT1 proteins.

Example 4 Preparation of cosmetic compositions

The quantities indicated are given as a percentage of weight.

1 - Anti-wrinkle cream:

Trade Names INCI Names% mass

PHASE A

Montanov 68 Cetearyl Alcohol (and) Cetearyl 6.00 Glucoside

The constituents of phase A and phase B are heated separately at a temperature between 65 ° C. and 70 ^° C., phase C is incorporated, then phase A is emulsified in phase B. The Carbomer is neutralized with the phase D at a temperature around 45 ° C. Phase E is then added with stirring and the cooling is continued to 25 ^° C. 2-Soothing cream:

The ingredients of phase A and phase B are weighed and heated separately at 60 ° C. When phase B reaches 60 ⁰ C, introduce phase C. Emulsify phase B in phase A. The Carbopol is neutralized with phase D at a temperature around 45 ^° C. Cooling is continued to below 40 ^° C. Phase E is then added with stirring.

3 - Firming Gel - Slimming - anti-cellulite:

Carbopol gel is prepared at 2%. The ingredients are added in the order listed above with stirring. The mixture is then neutralized with the TEA. The perfume and the dyes are added if necessary.

Claims

1. Delipidated extract of seeds of the Trigonella foenum graecum (fenugreek) species, in or for the preparation of a cosmetic or pharmaceutical composition intended for external topical administration, said extract forming an active agent inducing the endogenous synthesis of SIRT proteins in the cells of the skin, characterized in that it contains an amount of isoleucine amino acid, mono or polyhydroxylated, and / or one of these derivatives of between 10% and 40% of the total weight of the dry extract, and in that it is prepared according to a process comprising steps of extraction with an acidic aqueous solution and an alcohol, purification on an ion exchange column, and removal of impurities by an activated carbon.

2. Extract according to claim 1, characterized in that the fenugreek seeds are sprouted seeds or only the part of the seed containing the embryo or cotyledons.

3. Extract according to one of the preceding claims, characterized in that the SIRT proteins are SIRTl proteins.

4. Cosmetic or pharmaceutical composition for external topical administration, characterized in that it comprises an effective amount of 2% to 5% by weight of an extract according to one of claims 1 to 3.

5. Composition according to claim 4, characterized in that it further comprises another active agent.

6. Use of an effective amount of an extract according to one of claims 1 to 3, in or for the preparation of a cosmetic or pharmaceutical composition according to one of claims 4 or 5.

7. Use of an effective amount of an extract according to one of claims 1 to 3, in or for the preparation of a cosmetic or pharmaceutical composition according to one of claims 4 or 5, the composition being intended to fight in a curative and / or preventive manner against the manifestations of skin aging.

8. Use of an effective amount of an extract according to one of claims 1 to 3, in or for the preparation of a cosmetic or pharmaceutical composition according to one of claims 4 or 5, the composition being intended to protect skin and / or integuments against all types of external aggression.

9. Use of an effective amount of an extract according to one of claims 1 to 3, in or for the preparation of a cosmetic or pharmaceutical composition according to one of claims 4 or 5 to produce a localized thinning effect after application on the skin, and more particularly to reduce, eliminate or prevent subcutaneous fat overload.

10. Cosmetic skin treatment process intended to increase the endogenous synthesis of SIRT proteins in skin cells, characterized in that a composition containing, as active ingredient, at least one extract such as defined according to one of claims 1 to 3.

11. Cosmetic treatment method for reducing, eliminating and / or preventing subcutaneous fat overloads; and / or for fighting against cellulite; and / or to fight against the phenomenon of orange peel, characterized in that is applied to the skin a composition containing, as active ingredient, at least one extract as defined according to one of claims 1 to 3.