WO2003002086A2

WO2003002086A2 - Use of the tripeptide lys-pro-val(kpv) for improving the skin barrier function

Info

Publication number: WO2003002086A2
Application number: PCT/FR2002/002269
Authority: WO
Inventors: Yann Mahe
Original assignee: L'oreal
Priority date: 2001-06-29
Filing date: 2002-06-28
Publication date: 2003-01-09
Also published as: FR2826577A1; FR2826577B1; WO2003002086A3

Abstract

The invention relates to the use of a peptide containing at least the Lysine-Proline-Valine (KPV) sequence, or of a functional equivalent of one such peptide, in a composition intended to improve the skin barrier function. The invention also relates to a cosmetic treatment method designed to improve the skin barrier function by the application to the skin of compositions comprising a peptide containing at least the Lysine-Proline-Valine (KPV) sequence or a functional equivalent of one such peptide.

Description

USE OF Lys-Pro-Val (KPV) TRIPEPTIDE TO IMPROVE THE BARRIER FUNCTION OF THE SKIN

The invention relates to the use of a peptide containing at least the Lysine-Proline-Valine sequence (KPV), or of a functional equivalent of such a peptide, in a composition for improving the barrier function of the skin. . It also relates to a cosmetic treatment process intended to improve the barrier function of the skin by the application to the skin of compositions comprising a peptide containing at least the Lysine-Proline-Valine (KPV) sequence, or a functional equivalent of such a peptide.

Human skin is made up of two compartments, namely a deep compartment, the dermis and a superficial compartment, the epidermis.

The epidermis is in contact with the external environment. One of its roles consists in protecting the organism from dehydration and from external aggressions, chemical, mechanical or infectious.

The cells constituting the epidermis are delimited by an intercellular lipid structure. During differentiation, the phospholipids, the role of which is to develop the fluid structure of the cell membranes of the living layers of the epidermis, are gradually replaced by a mixture composed mainly of fatty acids, cholesterol and sphingolipids. (ceramides). These lipids are essential for water exchange and the “barrier” function of the epidermis.

The balance of the skin barrier and mucous membranes is dependent on complex biological mechanisms involving numerous growth factors, adhesion molecules, hormones and enzymes of lipid metabolism. In addition to transitional periods of dryness which can manifest themselves in any type of skin and in particular healthy skin, linked for example to climatic causes, There are situations during life where the dryness of the skin can become persistent, independently of the seasons, and in a variable way according to the affected individuals, for example, according to particular characteristics of their skin type or according to their physiological state or of their health. For example, a hormonal drop during menopause leads to a decrease in the content of skin lipids. The skin becomes drier and more easily prone to cracks and chapped skin.

A traditional solution consists in permanently providing external lipid agents, intended to compensate for this loss of lipids, to promote the suppleness of the skin and limit the appearance of cracks and crevices. Examples include body and hand creams, chapped lip sticks, etc.

The present invention uses substances capable of influencing the endogenous synthesis of lipids important for the barrier function.

In this context, the Applicant has in particular highlighted substances capable of significantly increasing the expression of genes coding for enzymes involved in the endogenous synthesis of lipids important for the barrier function. More particularly, substances capable of increasing the expression of genes coding for these enzymes have been identified in the first line of skin defense, epidermal keratinocytes.

Among the substances tested for their capacity to increase the expression of genes coding for certain enzymes in keratinocytes, peptide compounds and particularly the tripeptide of sequence Lysine-

Proline-Valine, hereinafter referred to as KPV, have given positive results.

The subject of the invention is therefore the use of peptide compounds, or functional equivalents of these compounds, to prevent, to improve, or even to remedy states of cutaneous dryness noticeable in the human skin or mucous membranes. Such conditions can be linked to a deficit in the balance of the skin and mucous membranes, influenced by agents of external or internal origin, and if necessary linked to physiological or pathological factors.

The compounds according to the invention have the capacity to allow, when administered particularly topically on the skin or mucous membranes, the prevention or improvement, in particular the attenuation or disappearance, of manifestations of cutaneous dryness.

In the context of the invention, the peptide compounds can be used for application to healthy skin, subject or which may be subject to the influence of agents such as climatic agents and therefore likely to manifest signs of especially transient skin dryness.

In other particular cases, the peptide compounds of the invention can be applied to the skin when it exhibits clinical signs of a cutaneous barrier deficit, for example linked to the activity of a pathological agent.

The tripeptide KPV corresponds to the three C-terminal amino acids of the hormone stimulating melanocytes type α (α - MSH), or Melanotropin.

A - MSH is a known natural peptide having 13 amino acid residues. This peptide was originally described as produced by the pituitary gland, but the brain in general, blood, skin and other tissues are capable of producing α - MSH activity.

In particular, it has been shown that keratinocytes of the epidermis are a source of α - MSH. A - MSH (1-13) is known for its antipyretic, anti-inflammatory and propigmenting activities. This neuropeptide is known to inhibit inflammation induced by cytokines or other mediators of inflammation, as well as by products with an irritant effect.

The antipyretic signal of - MSH, as well as its anti-inflammatory activity, resides in its carboxy-terminal sequence and can be mimicked by the tripeptide 11-13 carboxy-terminal (L) Lys (L) Pro (L) Val.

Thus, patents US 5028592 and US 5,157,023 aim to protect the use of the tripeptide in an anti-inflammatory and antipyretic treatment process.

In cosmetology, anti-sensitizing and anti-inflammatory properties of the KPV peptide have been described (patent applications EP-A-1092427, and EP-A-0764444), as well as the use of derivatives of a - MSH for stimulate hair growth (patent EP-A-759292).

The inventors studied the expression of several genes in keratinocytes and fibroblasts, in response to a synthetic peptide KPV. The results, presented in Example 1, show an increase in the transcription of the genes coding for two key enzymes involved in the synthesis of epidermal lipids and the constitution of the skin barrier function in keratinocytes, in response to this peptide. These are the enzyme HMG-CoA reductase and Fatty Acid Synthase (FAS), which are involved in the synthesis of cholesterol and fatty acids, respectively.

Harris et al. have shown that the level of messenger RNA for these two enzymes increases significantly in the skin after a break in the skin barrier by “tape stripping” or by acetone treatment. In addition, these authors showed that an artificial restoration of the barrier function prevented the increase in the mRNA levels of these enzymes, which indicates a specific link between certain needs of the barrier function and the increase in the level of these mRNAs (Harris et al., J. Invest. Dermatol. December 1997, n ° 109 (6): p. 783- 7).

The invention therefore relates, firstly, to the use of at least one peptide containing the tripeptide KPV, or of at least one functional equivalent of such a peptide, for the preparation of a cosmetic composition.

The invention also relates to the use of at least one peptide containing the tripeptide KPV, or at least one functional equivalent of such a peptide, for the preparation of a composition intended to stimulate the synthesis of lipids, particularly skin lipids. Such a composition is in particular intended to increase the expression of genes coding for enzymes involved in the synthesis of lipids, particularly by keratinocytes.

By “functional equivalent” of a peptide containing the KPV motif, is meant, within the meaning of the invention, any molecule capable of improving the appearance of the skin when the latter exhibits signs of cutaneous dryness. Alternatively, a “functional equivalent” of a peptide containing the KPV motif consists of any molecule having the capacity to increase the expression of the enzymes HMG-CoA reductase and Fatty Acid

Synthase (FAS), in cultured keratinocytes. A test to determine whether a molecule is a functional equivalent of the KPV peptide according to this latter definition, is to carry out, in the presence and in the absence of this molecule, an analysis of the expression of certain genes, as is for example presented in Example 1. By way of example, a functional equivalent according to the invention comprises a peptide containing a KPV motif, at least one of the amino acid residues of which may have been substituted, for example by a residue d amino acid with a similar hydropathic index. The invention also includes, for this reason, a molecule comprising a peptide part comprising the KPV motif, covalently linked to one or more other non-peptide groups, for the purposes of protection and / or vectorization and / or targeting of the tripeptide. Of course, the KPV tripeptide or a functional equivalent of this tripeptide are accessible within the molecules used in the context of the present invention, so that the functions of the KPV motif implemented in the context of the invention are essentially preserved . Preferably, the KPV motif is exposed on the surface of these molecules, in one or more copies.

In the remainder of this text, the term “peptide containing the tripeptide KPV” will denote both a peptide or a protein of more than three amino acids, in which the tripeptide KPV is present, as the tripeptide KPV alone, or that a functional equivalent of these peptides, as defined above.

More particularly, the invention relates to the use of at least one peptide containing the tripeptide KPV, for the preparation of a composition intended to improve the barrier function of the skin.

Even more particularly, the invention relates to the use of at least one peptide containing the tripeptide KPV, or of at least one functional equivalent of such a peptide, for the preparation of a composition intended to prevent, improve and / or remedy the external signs of skin dryness (dry skin).

The invention also relates to the use of at least one peptide containing the tripeptide KPV, for the preparation of a composition intended to prevent or limit the formation of cracks or crevices on the lips, hands, face or body.

The degradation of the barrier function of the skin may be of physiological origin. It is physiological, for example, when it is linked only at age, or at a hormonal drop, for example at the time of menopause. This degradation of the barrier function can cause simple skin discomfort and tightness, or chapped skin, or even crevices in the skin and / or mucous membranes. A particular aspect of the present invention is the use of at least one peptide containing the tripeptide KPV, for the preparation of a composition intended to improve the aesthetic appearance and the comfort of aged skin.

The conditions for the use of the peptide compositions according to the invention are adjusted according to the state of the treated skin, either that it is a cosmetic treatment intended to remedy external signs of skin dryness, or whether it is a therapeutic treatment of a skin condition showing signs of dry skin.

The degradation of the barrier function of the skin may moreover be linked to certain skin conditions or pathologies of infectious, allergic, nervous, traumatic or other origin. This is the case, for example, in subjects with burns, atopy, eczema, or psoriasis. In these cases, the skin barrier particularly needs to be strengthened in order to promote healing and, if necessary, to prolong the remission phases between acute attacks of dermatological conditions. Another aspect of the present invention is therefore the use of at least one peptide containing the tripeptide KPV, for the preparation of a composition intended for the therapeutic treatment of the skin. For example, the invention relates to the use of a peptide containing the tripeptide KPV, to prolong the phases of remission between acute attacks of dermatological conditions.

The peptide used according to the invention can of course be of natural origin. This implies that it may have been purified from natural biological material. The peptide can also be produced by genetic engineering.

It is also easy to chemically synthesize peptides, even of considerable length.

Thus, a more specific subject of the invention is the use of at least one peptide as defined above, characterized in that the peptide (s) is (or are) a (or are) peptide ( s) of natural or synthetic origin.

In a particular use according to the invention, the tripeptide KPV is found at the C-terminal end of the peptide. In another particular use according to the invention, the peptide is restricted to the tripeptide KPV. Finally, it may be one of the salts of said tripeptide KPV, such as for example an acetate, citrate, tartrate or fumarate salt.

It may be that for reasons of resistance to degradation, it is necessary to use according to the invention a protected form of the peptide. The form of protection must obviously be a biologically compatible form. Many forms of biologically compatible protections can be envisaged, such as, for example, the acylation or acetylation of the amino-terminal end or the amidation of the carboxy-terminal end.

Thus, the invention relates to a use as defined above, characterized in that the peptide is in a protected form or not.

Preferably, according to the invention, protection based on either the acylation or acetylation of the amino-terminal end, or on the amidation of the carboxy-terminal end, or on both, is used.

In the field of amino acids, the geometry of the molecules is such that they can theoretically be in the form of isomers different optics. There is indeed a molecular conformation of the amino acid (aa) such that it deviates to the right the plane of polarization of light (dextrorotatory conformation or D-aa), and a molecular conformation of the amino acid (aa) such that it deflects the plane of polarization of the light to the left (levorotatory conformation or L-aa).

Nature has only retained the levorotatory conformation for natural amino acids. Consequently, if the peptide used in the compositions according to the invention is of natural origin, it will consist of amino acids of the L-aa type.

However, chemical synthesis in the laboratory makes it possible to prepare amino acids having the two possible conformations. From this basic material, it is possible to incorporate, during the synthesis of peptides, both amino acids in the form of dextrorotatory and levorotatory optical isomers.

It is thus possible to incorporate during the synthesis of peptides amino acid residues Lysine, Proline, Valine, indifferently in their form D- Lysine (D-Lys), L-Lysine (L-Lys), D-Proline (D- Pro), L-Proline (L-Pro), D- Valine (D-Val) or L-Valine (L-Val).

Thus, the invention relates more particularly to the use of at least one peptide as defined above, characterized in that the amino acid residues of the tripeptide Lysine-Proline-Valine constituting the peptide are independently in the form of optical isomers dextrorotatory or levorotatory. It can also be a mixture of the two forms in any proportion, particularly a racemic mixture. Mention may thus be made of peptides containing at least one of the following tripeptides: D-Lys-D-Pro-D-Val, D-Lys-D-Pro-L-Val, D-Lys-L-Pro-D-Val, L-Lys-D-Pro-D-Val, D-Lys-L-Pro-L-Val, L- Lys-D-Pro-Val-L,

L-Lys-L-Pro-D-Val, L-Lys-L-Pro-L-Val.

According to the invention, it can of course be used more than one peptide. In this case, the mixture of peptides can consist of a combination of the peptides described above.

In a particular use according to the invention, the Praline residue of the tripeptide KPV is in the form of a dextrorotatory optical isomer (DPro).

In order to effectively fight against photoaging, it is possible to add to the composition prepared according to a use of the invention one or more complementary sun filters, active in UVA and / or UVB, hydrophilic or lipophilic, comprising optionally a sulfonic function. The sun filter is preferably chosen from organic filters and / or mineral filters.

The peptides comprising the tripeptide KPV are preferably used according to the invention for the preparation of a composition suitable for topical administration, that is to say containing a cosmetically or dermatologically acceptable medium, ie a medium compatible with the skin, nails, mucous membranes, tissue and hair.

In the uses of the invention, the peptide containing the tripeptide KPV or its functional equivalent, can be used at a concentration of between 10 ^"12 and 1 M, preferably between 10 ^{" 9} and 10 ^"1 M and, more preferably, between 10 ^"6 and 10 ^{" 3} . It is clear that a person skilled in the art knows how to adjust this quantity of material according to whether he uses a peptide containing the tripeptide Lysine-Proline-Valine, or any functional biological equivalent of such a peptide.

Furthermore, it has been shown that carbohydrate derivatives would allow specific stimulation of certain β-glucosidases manifested by the improvement of the barrier function of the skin and / or mucous membranes, particularly when the carbohydrate derivatives are applied by the topical (patent application FR 0014557). Example 2 shows the specific activation of β-D-glucosidases (lysosomials) of the stratum corneum, under the effect of a carbohydrate derivative, 0-octanoyl-6'-maltose. Β-D-glucosidases (lysosomials) are involved in the catabolism of glycolipids and in particular of ceramides. They are therefore specifically involved in the barrier function, in a completely complementary way to the enzymes HMG-CoA reductase and Fatty Acid Synthase.

A composition capable of both stimulating the expression of genes coding for key enzymes involved in the synthesis of fatty acids and cholesterol, and of activating key enzymes involved in the synthesis of ceramides, is therefore capable of effectively restoring the barrier function of the skin, both qualitatively and quantitatively.

The invention therefore relates to the use of a peptide containing the tripeptide KPV, for the preparation of a cosmetic and / or pharmaceutical composition, as described above, further characterized in that the composition also comprises at least a carbohydrate or carbohydrate derivative corresponding to the general formula (I),

R-X-A (I)

in which A represents a chain composed of one to twenty carbohydrate units or carbohydrate derivatives, each comprising 3 to 6 carbon atoms, linked together, preferably by acetal bridges, each of these units possibly being substituted, for example by a halogen, by an amino function, an acid function, an ester function, a thiol, an alkoxy function, a thio-ether function, a thio-ester function, an amide function, a carbamate function, a urea function,

R represents an alkyl chain or an alkenyl chain, comprising from 1 to 24, preferably from 4 to 24, carbon atoms, branched or linear, which can be interrupted by ether bridges, optionally carrying a hydroxyl function, a carboxylic acid function, a amino function, ester function, acyloxy function, amide function, ether function, carbamate function, urea function,

and X represents a function linking R and A such as for example an amino, ether, amide, ester, urea, carbamate, thioester, thioether, sulfonamide function.

Preferably, R represents an alkyl chain or an alkenyl chain, comprising from 4 to 24 carbon atoms, branched or linear, optionally carrying a hydroxyl function.

Each of the carbohydrate component A units may be a sugar or a sugar derivative. For example, each component unit A can be a reduced sugar, an amino sugar or a sugar carrying a carboxylic acid function.

Among the sugars or sugar derivatives which may enter into the constitution of A, mention may be made, for example, of the following products, which are commercially available, optionally in the form of a salt: N-acetyl-D-galactosamine, N-acetyl- D-glucosamine, N-acetyl-neuraminic acid, adonitol, D-allose, D-altrose, 6-amino -6-deoxy-D- glucose, 1, 6-anhydroglucose, acid arabinic, arabinogalactan, D- arabinose, L-arabinose, D, L-arabinose, D-arabitol, D-cellobiose, D-glucosamine, D-galactosamine, 2-deoxy-D-glucose, 6-deoxy-D- galactose, 6-deoxy-L-galactose, galactitol, mesoerythritol, D- erythrose, D-fructose, D-fucose, L-fucose, D-galactaric acid, galactitol, galactomannan, D-galactono-1, 4-lactone, L-galactono-

1, 4 -lactone, D-galactosamine, D-galactose, L-galactose, D- galacturonic acid, gentiobiose, glucamine, D-glucaric acid, D- glucono-1, 5- lactone, L-glucono-1, 5-lactone, D-glucosamine, D-glucosaminic acid, D-glucoronic acid, L-glucose, D-glucose, isomaltitol, isomaltotriose, isomaltose, lactobionic acid, D-lactose, lactulose, D-lyxose, L-lyxose, lyxosamine, maltitol, D- maltose, maltotetraose, maltotriitol, maltotriose, D- mannosamine, D-mannose, L-mannose, D-melezitose, D-melibiose, D-raffinose, undeca-acetate of D-raffinose, L-rhamnose, D-ribose, L- ribose, D-ribulose, rutinose, D- sucrose, a sophorose, sorbitol, D-tagatose, D-talose, D-threose, turanose, D-xylitol, D-xylose , L-xylose, D, L-xylose.

Preferably, A will be chosen from the following hydrocarbon chains:

D-glucosamine or 2-amino-2 deoxy-D-glucose, D-glucamine or 1-amino-1-deoxy-D-glucitol, N-methyl-glucamine, D-glucose, D-maltose, sorbitol, maltitol.

Preferably, R comprises 4 to 16 carbon atoms such as for example the n-butyl, n-octyl, 2-ethyl-hexyl, n-dodecyl radicals.

The peptides comprising the tripeptide KPV and, where appropriate, the carbohydrate derivatives, are preferably used according to the invention for the preparation of a composition suitable for topical administration, that is to say containing a medium cosmetically or dermatologically acceptable, ie a medium compatible with the skin, nails, mucous membranes, tissues and hair.

The invention also relates to a composition intended for improving the barrier function of the skin and comprising at least one peptide containing the tripeptide KPV or a functional equivalent of such a peptide, and a carbohydrate according to (I).

According to the invention, the preferred compositions will comprise, in addition to a peptide comprising the tripeptide KPV, at least one product chosen from:

N-butanoyl-D-glucosamine, N-octanoyl-D-glucosamine, N- octyloxycarbonyl-N-methyl-D-glucamine, N-2-ethyl-hexyloxycarbonyl-N- methyl-D-glucamine, 6 '-0-octanoyl-D-maltose, 6'-0-dodecanoyl-D-maltose.

The preparation of products (I) is well known to those skilled in the art, reference may for example be made to the following documents: FR-A-2703993, FR-A-2715933, EP-A-577506, EP-A-566438 and EP-A-485251.

More preferably, a carbohydrate derivative corresponding to formula (I) is 0-octanoyl-6'-maltose.

In the compositions according to the invention, the carbohydrate according to (I) or the mixture of carbohydrates according to (I) can be used in an amount ranging from 0.05 to 20% by weight relative to the total weight of the composition and in particular in an amount ranging from 0.2 to 10% and better still from 0.5 to 5% by weight relative to the total weight of the composition. The peptide comprising the tripeptide KPV is for its part preferentially used in an amount ranging from 10 ^"6 % to 10 ^{" 3} % by weight relative to the total weight of the composition.

It is also clear that the effective quantity of active agent corresponds to the quantity necessary to obtain the desired result, and that the formulation of the compositions according to the invention depends on the use for which these compositions are intended. In particular, two main categories of compositions according to the invention can be distinguished, depending on the conditions under which they will be applied to the skin. The first category corresponds to cosmetic compositions, that is to say intended to be applied to healthy skin in order to improve its aesthetics and, where appropriate, comfort. Healthy skin is defined by the absence of pathologies such as infections, inflammation, erythema, or wounds such as a burn or a cut. However, in this definition, healthy skin does not mean skin in perfect condition. In particular, healthy skin may exhibit signs of dryness which may be of exogenous origin (the skin becomes dry, for example, upon exposure to dry and very cold air), or of endogenous physiological origin (for example example, at the time of the hormonal fall linked to menopause). In a particular embodiment of the invention, a peptide containing the tripeptide KPV is used for the preparation of a composition formulated for cosmetic use, on healthy skin showing signs of dryness.

More particularly, in the cosmetic composition, the peptide is present in an amount such that the tripeptide Lysine-Proline-Valine is at a concentration between 10 ^"12 M and 10 ^{" 3} M, and preferably between 10 ^"9 M and 10 ^"4 M.

The invention therefore relates to a cosmetic composition formulated to be applied to the skin when it exhibits signs of dryness, comprising at least one peptide containing the tripeptide KPV or at least one functional equivalent of such a peptide, said composition making it possible to prevent, absorb and / or eliminate these signs of dryness.

According to the invention, a peptide containing the tripeptide KPV can also be used for the preparation of a therapeutic composition, intended for improve the condition of damaged skin. The lesion considered can be of any origin, for example infectious, allergic, nervous or traumatic. A therapeutic composition can be applied directly to the injured area or in its vicinity, or even, in the case of pathologies presenting periods of crises and periods of rest, in a site having presented a lesion, as a preventive measure, to prolong a state of remission between two crises. Thus, the invention also relates to the use of at least one peptide comprising the tripeptide KPV, such as the uses mentioned above, for the preparation of a composition formulated for therapeutic use, on injured skin having signs of drought.

More particularly, in the preparation of a composition for therapeutic use, the peptide is present in an amount such that the tripeptide Lysine-Proline-Valine can be used at a concentration of between ^10'12 M and 1 M, and preferably included between 10 ^"6 M and

10 ^"1 M. The composition will then be formulated with a pharmaceutically acceptable vehicle.

According to a preferred embodiment of the invention, the composition has a pH close to that of the skin, between 4 and 7. When applied topically, the composition comprising at least one peptide containing the tripeptide KPV or at least one functional equivalent of such a peptide can be applied to the face, the neck, the scalp, the mucous membranes and the nails or any other cutaneous zone of the body.

The composition is preferably in a form suitable for topical administration. It is in particular in the form of aqueous, hydroalcoholic or oily solutions, dispersions of the lotion or serum type, anhydrous or oily gels, emulsions of liquid or semi-liquid consistency of the milk type, obtained by dispersion of a fatty phase. in an aqueous phase (O / W) or conversely (W / O), suspensions or emulsions of soft, semi-solid or solid consistency of the cream, gel, micro-emulsion type, or else of micro-capsules, of micro-particles, or of vesicular dispersions of ionic and / or non-ionic type. These compositions are prepared according to the usual methods.

The amounts of the various constituents of the compositions used according to the invention are those conventionally used in the fields considered.

These compositions constitute in particular protective, treatment or care creams for the face, for the hands or for the body, body protection or care milks, lotions, gels or foams for the care of the skin and mucous membranes. or for cleaning the skin, masks or patches.

The compositions can also consist of solid preparations constituting soaps or cleaning bars.

In a known manner, the compositions used according to the invention may also contain adjuvants customary in the cosmetic and dermatological fields, such as hydrophilic or lipophilic gelling agents, hydrophilic or lipophilic active agents, preservatives, antioxidants, solvents, perfumes, fillers and coloring matters. The compositions according to the invention may also contain any other compound having hydrating properties and / or improving the barrier function. The amounts of these various adjuvants are those conventionally used in the fields considered, and for example from 0.01% to 20% of the total weight of the composition. Of course, those skilled in the art will take care to choose this or these optional additives and / or their amounts in such a way that the advantageous properties intrinsically attached to the composition according to the invention are not, or not substantially, altered. by the addition (s) envisaged. As oils which can be used in the invention, mention may be made of mineral oils (petroleum jelly oil), vegetable oils (shea oil, sweet almond oil), animal oils, synthetic oils, silicone oils (cyclomethicone) and fluorinated oils (perfluoropolyethers). Fat can also be used as fatty alcohols, fatty acids (stearic acid), waxes (paraffin, carnauba, beeswax).

As emulsifiers which can be used in the invention, mention may be made of Polysorbate 60 and sorbitan stearate sold respectively under the trade names Tween 60 and Span 60 by the company ICI. Co-emulsifiers such as PPG-3 myristyl ether sold under the trade name Emcol 249-3K by the company Witco can be added to it.

As solvents which can be used in the invention, mention may be made of water, lower alcohols, in particular ethanol and isopropanol, propylene glycol.

As hydrophilic gelling agents, mention may be made of carboxyvinyl polymers (carbomers), acrylic copolymers such as acrylate / alkylacrylate copolymers, polyacrylamides, polysaccharides such as hydroxypropylcellulose, natural gums (xanthan) and clays, and, as lipophilic gelling agents, mention may be made of modified clays such as bentones, metallic soils of fatty acids such as aluminum stearates, hydrophobic silica, polyethylenes and ethylcellulose.

As hydrophilic active agents, it is possible to use proteins or protein hydrolysates, amino acids, polyols, urea, allantoin, sugars and sugar derivatives, water-soluble vitamins, starch, bacterial extracts or plants, especially Aloe Vera.

As lipophilic active agents, one can use tocopherol (vitamin E) and its derivatives, essential fatty acids, ceramides, essential oils. In order to effectively fight against photoaging, it is also possible to add to the composition according to the invention one or more complementary sunscreens, active in UVA and / or UVB, hydrophilic or lipophilic, optionally comprising a sulfonic function. The sun filter is preferably chosen from organic filters and / or mineral filters.

As organic filters, mention may be made in particular of cinnamic derivatives, salicylic derivatives, camphor derivatives, triazine derivatives, benzophenone derivatives, dibenzoylmethane derivatives, β- β-diphenylacrylate derivatives, l derivatives p-aminobenzoic acid, the filter polymers and filter silicones described in application WO-93/04665 or else the organic filters described in patent application EP-A 0 487 404.

As mineral filters, mention may in particular be made of pigments or else nanopigments (average size of the primary particles: generally between 5 nm and 100 nm, preferably between 10 and 50 nm) of coated or uncoated metal oxides, such as for example nanopigments of titanium oxide (amorphous or crystallized in rutile form and / or anatase), iron, zinc, zirconium or cerium which are all well known photoprotective agents acting by physical blocking

(reflection and / or diffusion) of UV radiation. Conventional coating agents are moreover alumina and / or aluminum stearate. Such nanopigments of metal oxides, coated or uncoated, are in particular described in patent applications EP-A-0 518 772 and EP-A-0 518 773.

As examples of complementary sun filters active in UV-A and or UV-B, we can cite:

- p-aminobenzoic acid, - oxyethylenated p-aminobenzoate (25 mol),

- 2-ethylhexyl p-dimethylaminobenzoate,

- N-oxypropylenated ethyl p-aminobenzoate,

- glycerol p-aminobenzoate, - homomenthyl salicylate,

- 2-ethylhexyl salicylate,

- triethanolamine salicylate,

- 4-isopropylbenzyl salicylate,

- 4-ter-butyl-4'-methoxy-dibenzoylmethane (PARSOL 1789 by GIVAUDAN ROURE)

- 2-ethylhexyl p-methoxycinnamate (PARSOL MCX by GIVAUDAN ROURE)

- 4-isopropyl-dibenzoylmethane (EUSOLEX 8020 from MERCK),

- menthyl anthranilate, - 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate, (UVINUL N539 from BASF),

- ethyl-2-cyano-3,3'-diphenylacrylate,

- 2-phenyl benzimidazole 5-sulfonic acid and its salts,

- 3- (4'-trimethylammonium) -benzylidèn-boman-2-on-methylsulfate,

- 2-hydroxy-4-methoxybenzophenone (UVINUL MS 40 from BASF), - 2-hydroxy-4-methoxybenzophenone-5-sulfonate (UVINUL MS 40 from

BASF)

- 2,4-dihydroxybenzophenone (UVINUL 400 from BASF),

- 2,2 ', 4,4'-tetrahydroxybenzophenone (UVINUL D 50 from BASF),

- 2,2'-dihydroxy-4,4'-dimethoxybenzophenone (HELISORB II from NORQUAY),

- 2-hydroxy-4-n-octoxybenzophenone,

- 2-hydroxy-4-methoxy-4'-methylbenzophenone,

- α- (2-oxoborn-3-ylidene) -tolyI-4-sulfonic acid and its salts,

- 3- (4'-sulfo) benzyIidèn-bornan-2-one and its salts, - 3- (4'-methylbenzylidene) -d, l-camphor, - 3-benzylidene-d, l-camphor,

- benzene acid 1, 4-di (3-methylidene-10-camphosulfonic) and its salts (MEXORYL SX from CHIMEX),

- urocanic acid, - 2,4-6-tris- [p- (2'-ethylhexyl-1'-oxycarbonyl) anilino] -1, 3,5-triazine,

- 2- [p- (tertiobutyIamido) anilino] -4,6-bis [p- (2'-ethylhexyl-1'-oxycarbonyl) anilino] -1, 3,5-triazine,

- 2,4-bis [4-2-ethyl-hexyloxyl] -2-hydroxyl-phenyl! ^> -6- (4-methoxyphenyl) -1, 3,5-triazine, - the polymer of N- (2 and 4) - [2-oxoborn-3-yliden) methyl) benzyl] - acrylamide,

- 4,4-bis-benzimidazolyl-phenylen-3,3 ', 5,5'-tetrasulfonic acid and its salts,

- 2,2'-methylen-bis- [6- (2H-benzotriazol-2-yl) -4- (1, 1, 3,3-tetramethylbutyl) phenol],

- polyorganosiloxanes with a malonate function.

The invention also relates to a method for increasing the expression of the enzymes HMG-CoA reductase and Fatty Acid Synthase (FAS) by cells in culture, particularly keratinocytes, comprising applying to said cells, a composition containing at least a peptide containing the tripeptide KPV or a functional equivalent of such a peptide.

The invention also relates to a method for activating the synthesis of lipids by cells in culture, particularly keratinocytes, comprising applying to said cells, a composition containing at least one peptide containing the tripeptide KPV or a functional equivalent of such a peptide.

The above methods can be implemented for example in order to improve the quality of skin cultures intended for grafting. They can be carried out on pure cultures of keratinocytes, but also on mixed cultures, for example co-cultures of keratinocytes and fibroblasts.

These methods can also be implemented in vivo, by topical administration of a composition comprising at least one peptide containing the tripeptide KPV or at least one functional equivalent of such a peptide.

Thus, the invention relates to a method for increasing the expression of the genes coding for the enzymes HMG-CoA reductase and Fatty Acid Synthase (FAS) by cells, particularly keratinocytes and to a method for activating the synthesis of lipids by cells, particularly keratinocytes, consisting in applying to the skin, a composition containing at least one peptide containing the tripeptide KPV or at least one functional equivalent of such a peptide.

Finally, the invention relates to a cosmetic treatment process for the skin, intended to improve the barrier function, consisting in applying to the skin a composition containing at least one peptide containing the tripeptide KPV or at least one functional equivalent of such a peptide .

The experimental part presents the results obtained from in vitro studies on the effect of a synthetic KPV peptide (Example 1). The effect of a carbohydrate derivative on the activity of the glucosidases of the stratum corneum is then presented (Example 2). Finally, examples of compositions used according to the invention to improve the barrier function are indicated, without being limiting. EXPERIMENTAL PART

Figure 1 is a graph illustrating the effect of 0-octanoyl-6'-maltose on glycosidases of the stratum corneum. The activity is expressed as a percentage of activity relative to the value measured in the absence of O-octanoyl-6'-maltose.

Example 1 Study of the Effect of a Synthetic KPV Peptide on the Expression of 475 Genes in Cultured Keratinocytes

Normal human epidermal keratinocytes (NHEK) are precultured at high density in 4 flasks of 175 cm ² , in SFM medium

(Gibco 17005034), defined medium, poor in calcium (0.09 mM), without EGF and without pituitary extract, to near confluence, at 37 ° C, 5% CO ₂ . The culture medium is then replaced by medium containing the tripeptide KPV [(D) K (D) P (D) V] at a final concentration of 5.10 ^"4 % (weight / volume: g / 100 ml) or of the control medium The cells of the various dishes are harvested after 18 h rapidly by trypsinization, in sterile RNAse-free tubes, according to the standard protocol and immediately frozen at -80 ° C.

The extraction / purification of the total RNA of each culture is carried out according to the method recommended by Clontech (Palo Alto, USA).

The total RNA solutions are adjusted to 1 μg / μl and treated with DNAse I, to remove any trace of DNA contaminating the RNA, according to the supplier's recommendations.

The messenger RNAs (mRNAs) are purified by hybridization of the poly (A) ends of the mRNAs to biotinylated oligo (dT) primers and selective capture on streptavidin beads, according to the AtlasPure protocol (Clontech). The ³² P-labeled multiple DNA probes are produced by reverse transcription of the mRNAs linked on poly (dT) beads, using a pool of primers specific for the sequences immobilized on the “arrays”, in the presence of [α ³² P] -dATP. This step used the reagents and the protocol recommended by Clontech.

The labeled probes are purified by chromatography on exclusion columns and the quality and equivalence of the labeled probes is evaluated by counting in liquid scintillation.

Four “Custom ATLAS BlOalternatives” membranes grouping together 475 genes are pretreated, then the cDNAs immobilized on each membrane are hybridized (68 ° C., overnight) to the corresponding labeled probes; the filters are then washed extensively (68 ° C) and placed in individual plastic bags for analysis.

The analysis was carried out by direct quantification of the radioactivity of the spots using a Cyclone Phosphorlmager (Packard instruments; 24 h acquisition).

The results show a stimulation of the expression of the genes of HMG-CoA reductase and of FattyAcid synthase greater than twice in the presence of the tripeptide.

Example 2 Study of a carbohydrate derivative, I 'O-octanoyl-6'- maltose [-D-glucopyrannosyl-1-4-D-glucopyrannose] on the stimulation of glycosidase activities

Effect of 0-octanoyl-6'-maltose on the activity of stratum corneum glycosidases:

In order to determine the nature and extent of the barrier effect of a carbohydrate derivative according to the invention, the influence of O-octanoyl-6'-maltose on glycosidase activity was studied using the following enzyme assay:

The assay is carried out in a 96-well plate. A mixture is produced comprising:

- 75 μl of a 10 mM solution of specific chromogenic substrate coupled to para-nitro-phenol (PNP),

- 10 μl of 700 mM citrate buffer / 200 mM sodium phosphate, pH 4.5, - 55 μl of a 0.5 M solution of 0-octanoyl-6'-maItose [-D- glucopyrannosyl-1-4- D-glucopyranose]

- 40 μl of solution of soluble glycosidases of the stratum corneum. This solution is obtained by simple scraping of the forearm in a 70 mM sodium citrate buffer, pH 4.5 containing 1% of Tween 20 and elimination of the cellular debris by sequential filtration on a membrane with a porosity of 0.45 and 0 , 22 μm.

The measurements are carried out by quantification of the yellow coloration after an incubation at 37 ° C. for a period of between 1 h 30 and 48 hours.

The results presented in FIG. 1 show that among the glycosidases tested, only β-D-glucosidase shows kinetics influenced by 0-octanoyl-6'-maltose. The other glycosidases are either indifferent to the presence of 0-octanoyl-6'-maltose, or very weakly inhibited. Β-D-glucosidases (lysosomials) are involved in the catabolism of glycolipids and in particular glucosyl-ceramides into ceramides. They are therefore specifically involved in the barrier function.

Example 3: Examples of Formulations Composition 1: Face Milk

- Vaseline oil 7.0 g

- Tripeptide KPV 0.005 g - 0-octanoyl-6'-maltose (optional) 1.0 g

- Glyceryl monostearate, polyethylene glycol stearate (100 EO) 3.0 g

- 0.4 g carboxyvinyl polymer

- Stearyl alcohol 0.7 g - Soy protein 3.0 g

- NaOH 0.4 g

- Preservative qs

- Water qs 100 g

This composition is in the form of a facial milk, having good cosmetic properties, and being soft and comfortable to use.

The pH of the composition is approximately 5.5. Composition 2: Lotion

- Tripeptide KPV 0.001 g

- O-octanoyl-6'-maltose (optional) 0.5 g - 2-ethylhexyl palmitate 10.0 g

- Cyclopentadimethylsiloxane 20.0 g

- Butylene glycol 5.0 g

- Preservative qs - Water qs 100 g

This lotion, which contains no surfactant, promotes flaking of the skin.

Composition 3: Milk - Octyl palmitate 35.0 g

Glygerine 2.0 g

- Tripeptide KPV 0.0005 g

- 0-octanoyl-6'-maltose (optional) 0.8 g

Acrylic crosslinked polymer C10-C30 / alkylacrylates 0.1 g - Triethanolamine 0.1 g

Wheat amino acids 1.0 g

Conservative qs

Water qs 100 g

The milk obtained, which contains no surfactant, has good cosmetic properties.

Composition 4: Face gel

- Glycerin 10.0 g

- Tripeptide KPV 0.025 g - 0-octanoyl-6'-maltose (optional) 1.0 g

Disodium cocoamphodiacetate 1.0 g

Conservative qs

Water qs 100 g

The gel obtained has good cosmetic properties.

Composition 5: Cleansing gel with water

Butylene glycol 7.0 g

Sauroslate sodium lauroyl 4.0 g - Tripeptide KPV 0.01 g

- O-octanoyl-6'-maItose (optional) 1.0 g

Triethanolamine 0.8 g

Carbomer 0.5 g

Conservative qs

Water qs 100 g

The gel obtained has good cosmetic properties.

Claims

1. Use of at least one peptide containing the tripeptide KPV or at least one functional equivalent of such a peptide, for the preparation of a cosmetic composition.

2. Use according to claim 1, for the preparation of a composition intended to stimulate the synthesis of lipids, particularly lipids of the skin.

3. Use according to claim 1 or 2, for the preparation of a composition intended to improve the barrier function of the skin.

4. Use of at least one peptide containing the tripeptide KPV or of at least one functional equivalent of such a peptide, for the preparation of a composition intended to prevent, improve or remedy conditions of cutaneous dryness and / or mucous membranes.

5. Use of at least one peptide containing the tripeptide KPV or at least one functional equivalent of such a peptide, for the preparation of a composition intended to improve the aesthetic appearance and the comfort of the skin.

6. Use according to any one of claims 1 to 5, for the preparation of a composition intended to limit the formation of cracks or crevices on the lips, hands, face or body.

7. Use according to any one of claims 1 to 6, characterized in that the tripeptide KPV is located at the C-terminal end of the peptide.

8. Use according to any one of claims 1 to 7, characterized in that the peptide containing the tripeptide KPV, is the tripeptide KPV.

9. Use according to any one of claims 1 to 8, characterized in that the peptide containing the tripeptide KPV or its functional equivalent, is one of the salts of said tripeptide KPV.

10. Use according to claim 9, characterized in that the salt of the tripeptide KPV is an acetate, citrate, tartrate or fumarate salt.

11. Use according to any one of claims 1 to 10, characterized in that the peptide containing the tripeptide KPV or its functional equivalent, is protected by acylation or acetylation and / or amidation.

12. Use according to any one of claims 1 to 11, characterized in that the Lysine, Praline and Valine residues of the tripeptide KPV are independently in the form of levorotatory or dextrorotatory optical isomers, or in the form of a mixture in any proportion , particularly of a racemic mixture.

13. Use according to any one of claims 1 to 12, characterized in that the Praline residue of the tripeptide KPV is in the form of dextrorotatory optical isomer (DPro).

14. Use according to any one of claims 1 to 12, characterized in that the composition also comprises at least one carbohydrate or carbohydrate derivative corresponding to the general formula (I),

R-X-A (I)

in which A represents a chain composed of one to twenty carbohydrate units or carbohydrate derivatives, each comprising

3 to 6 carbon atoms, linked together, preferably by acetal bridges, each of these units possibly being substituted, for example by a halogen, by an amino function, an acid function, an ester function, a thiol, an alkoxy function, a thio-ether function, a thio-ester function, an amide function, a carbamate function, a function urea,

and X represents a function connecting R and A.

15. Use according to claim 14, in which X is a function chosen from amine, ether, amide, ester, urea, carbonate, thioester, thioether or sulfonamide functions.

16. Use according to any one of claims 1 to 15, characterized in that the composition also comprises at least one complementary sunscreen, active in UVA and / or UVB, hydrophilic or lipophilic, and optionally comprising a function sulfonic acid.

17. Use according to any one of claims 1 to 16, characterized in that the composition is formulated for topical administration.

18. Use according to any one of claims 1 to 17 characterized in that the peptide containing the tripeptide KPV or its functional equivalent, is used at a concentration between 10 ^"12 M and 10 ^" 3M, preferably between 10 ^{" 9} M and 10 ^-4 M.

19. Use according to any one of claims 1 to 18, for the preparation of a composition formulated for cosmetic use, on healthy skin showing signs of dryness.

20. Use according to any one of claims 1 to 17, for the preparation of a composition formulated for therapeutic use, on injured skin showing signs of dryness.

21. Use according to claim 20, characterized in that the peptide containing the tripeptide KPV or functional equivalent thereof, is used at a concentration ranging from 10 ^"12 M and 1 M, preferably between 10- ⁶ and 10- M.

22. Composition intended for improving the barrier function of the skin and comprising at least one peptide containing the tripeptide KPV or a functional equivalent of such a peptide, and a carbohydrate according to

(I).

23. Cosmetic composition formulated to be applied to the skin when it exhibits signs of dryness, comprising at least one peptide containing the tripeptide KPV or at least one functional equivalent of such a peptide, said composition making it possible to absorb and / or remove said signs of dryness.

24. Method for increasing the expression of genes coding for the enzymes HMG-CoA reductase and Fatty Acid Synthase (FAS) by keratinocytes in culture, consisting in applying to said keratinocytes, a composition containing at least one peptide containing the tripeptide KPV or at least one functional equivalent of such a peptide.

25. A method of activating the synthesis of lipids by keratinocytes in culture, consisting in applying to said keratinocytes, a composition containing at least one peptide containing the tripeptide KPV or at least one functional equivalent of such a peptide.

26. A method of cosmetic treatment of the skin intended to improve the barrier function, consisting in applying to the skin a composition containing at least one peptide containing the tripeptide KPV, or a functional equivalent of such a peptide

27. A method of cosmetic treatment of the skin intended to improve the hydration of the skin, comprising applying to the skin a composition containing at least one peptide containing the tripeptide KPV, or a functional equivalent of such a peptide

28. A method of cosmetic treatment of the skin intended to remedy dry skin conditions, comprising applying to the skin a composition containing at least one peptide containing the tripeptide KPV, or a functional equivalent of such a peptide