EP1385472A2

EP1385472A2 - Filtering suntan product

Info

Publication number: EP1385472A2
Application number: EP02726261A
Authority: EP
Inventors: Rainer Schmidt; Marcelle Regnier; Christine Duval
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2001-04-09
Filing date: 2002-04-09
Publication date: 2004-02-04
Also published as: FR2823112A1; JP3870164B2; JP2004525161A; FR2823112B1; US20040170580A1; WO2002080878A3; WO2002080878A2

Abstract

The invention concerns a product comprising at least a UV radiation filtering agent and at least a compound stimulating melanin synthesis, a composition comprising at least said product and the use of said product in a composition or for preparing a composition designed to protect the skin against the harmful action of UV radiation, as well as a cosmetic skin treatment method.

Description

Tanning and filtering product

The subject of the invention is a product comprising at least one agent which filters ultraviolet radiation and at least one compound which stimulates the synthesis of. melanin, a composition comprising at least said product, the use of said product in a composition or for the preparation of a composition intended to protect the skin from the harmful action of ultraviolet radiation, as well as a method of cosmetic treatment of the skin.

Solar radiation is composed, among other things, of type A ultraviolet radiation of wavelengths between 320 nm and 400 nm (UV-A), of type B ultraviolet radiation of wavelengths between 280 and 320 nm (UV-B) and type C ultraviolet radiation of wavelengths between 200 and 280 nm (UV-C).

UV-B are highly energetic and not very penetrating, poorly represented in sunlight, dependent on climatic variations (cloudy weather, overcast, etc.) and their presence varies according to the hours of the day (notion of peak (zenith)) . UV-A is less energetic than UV-B but more penetrating, present in large quantities in sunlight (at least 100 times more UV-A than UV-B), little dependent on climatic variations and present whatever time of day. UV-C is highly energetic and not very penetrating. They are stopped by the ozone layer and theoretically do not arrive on earth. But potentially they can be responsible for damage to nucleic acids.

It is known that solar radiation is responsible for beneficial effects on the skin, such as browning, but that it is also capable of inducing damage thereof, in particular in the case of so-called skin " sensitive "or continuously exposed skin. As a benefit, browning, commonly known as tanning, is an essential part of the skin's defense system. In fact, in response to ultraviolet radiation, the melanocytes in the basal layer of the epidemic synthesize melanin which, once incorporated into keratinocytes, constitutes a natural filter located on the surface of the skin, a filter which absorbs ultraviolet radiation. Melanin, in the form of a particle, can also act as a UV-reflecting screen. This is intended to decrease the amount of ultraviolet radiation that passes through the layers of the skin in order to prevent it from reaching the deep layers and causing harmful damage to the skin.

We also know how important it is to look good and how tanned skin is always a sign of good health. Hence the craze for prolonged exposure to ultraviolet radiation to acquire a sufficient tan.

However, as harmful effects, it is known that excessive exposure of the skin to solar radiation, and to ultraviolet radiation in particular, can cause a change in the elasticity of the skin, in its content of certain compounds, and so promote the acceleration of the skin's natural aging process. This accelerated or premature aging process due to radiation! Ultraviolet is generally called photoaging or actinic aging or dermatoheliosis. Weakly penetrating UV-B mainly affects the epidermis. The role of UV-B has been clearly demonstrated in the induction of UV-induced skin cancer. In fact, their main chromophore is nucleic acids, in particular deoxyribonucleic acid, within which they induce lesions and / or mutations (Eller MS, 1995, in Photodamage. 26-56, Blackwell ed.). The UV A rays which cross the epidermis and reach the dermis, are strongly involved in photoaging of the skin: they contribute for example to the appearance of solar elastosis. Furthermore, it is known that photosensitization reactions and photodermatoses such as polymorphic dermatitis are mediated mainly by UVA.

UVA is also mutagenic (Stary A. Mutation Res. 1997; 398: 1-8) and photocarcinogenic (De Laat A., 1998, in Protection of the skin against ultraviolet radiations. 19-23, John Libbey Eurotext ed) and in addition with UVB, can contribute to the development of skin cancer.

With the development of tanning salons or the use of UVA lamps at home favoring massive and prolonged exposure to UVA, it is shown that UVA alter the melanocyte and cause the appearance of pigmentation spots (lentîgo) and the increase in risk of developing melanoma (RϋngerTM Photodermatol. Photoimmunol. Photmed. 1999; 15-212-216)

We therefore understand the dilemma which exists on the one hand wanting to expose oneself to ultraviolet radiation to present a tanned appearance and on the other hand the absolute need to protect oneself from these same radiations because of their harmful effects.

Until now, one of the solutions proposed is to provide compositions comprising a filtering agent having an average protection index allowing both a certain protection and a certain browning. Indeed, if the filtering agent is in high quantity, it will all the more limit the stimulation by the ultraviolet rays of the synthesis of melanin by the melanocytes. Conversely, a composition containing a small or medium amount of filtering agent does not have sufficient guarantees in terms of protection against the harmful effects of ultraviolet radiation, nor does it provide sufficient satisfaction in terms of obtaining browning. . In addition, certain associations have been proposed to reinforce the browning of the skin, with a sunscreen.

Compositions containing psoralen derivatives and a filtering agent have thus been described in FR 2409751 or FR 2797585. However, to promote pigmentation, psoralen derivatives such as 5-methoxy psoralen require simultaneous irradiation of the skin with doses of 'UVA, which can damage DNA; in addition, the use of such psoralen derivatives is not desirable since they could be involved in photosensitization reactions. Combinations of UV filters with tyrosine or xanthines have also been proposed, in particular in FR 2 624 374 or FR 2 607 699; however, the activity of these preparations has not been demonstrated, and they also require significant irradiation of the skin, and often additional adjuvants. CH 642357 describes compositions containing tyrosine derivatives of UV filters and chromophoric derivatives.

WO 91/07945 or EP 380335 propose the use of xanthines to promote tanning, possibly associated with a sunscreen. However, the efficacy of xanthines as a browning agent in humans is not satisfactory. WO 98/25584 claims anti-inflammatory and activating melanogenesis compositions containing α MSH and SOD derivatives, to which titanium oxide can be added. It is known that derivatives of this hormone can have activities on various functions of the organism and in addition have a weak pro-pigmenting power.

There therefore remains a need for a filtering composition which on the one hand would have a high filtering power and on the other hand an ability to stimulate browning in equally high proportions.

The Applicant has now shown that the combination of an agent filtering ultraviolet radiation and a compound stimulating the synthesis of melanin has a surprising effect which leads to the production of a filtering and tanning product having filtering qualities. and a high stimulation capacity for the synthesis of meianin.

The primary object of the invention is therefore a product composed by at least the combination of at least one agent which filters ultraviolet radiation and one agent which stimulates the synthesis of melanin.

These compositions solve the problem of obtaining browning and protection of the skin equivalent to that obtained after sun exposure without subjecting it to the risks induced by irradiation by UV radiation, in particular UVA rays. The subject of the invention is also a composition comprising at least the combination of at least one agent which filters ultraviolet radiation and one agent which stimulates the synthesis of melanin.

Preferably, the agent stimulating the synthesis of melanin is an agent which is not likely to cause systemic side effects on the organism, in particular hormonal, nor phenomena of photosensitization.

The ultraviolet radiation filtering agent 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, derivatives of p-aminobenzoic acid, the filter polymers and filter silicones described in application WO-93/04665 or also the organic filters described in patent application EP-A 0487404.

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 metallic oxides coated or not, 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 metallic oxides, coated or uncoated, are in particular described in patent applications EP-A- 0 518 772 and EP-A- 0 518

773. Examples of active solar filters in UV-A and / or UV-B include:

p-aminobenzoic acid, oxyethylenated p-aminobenzoate (25mol), 2-ethylhexyl p-dimethylaminobenzoate, N-oxypropylenated ethyl p-aminobenzoate, glycerol p-aminobenzoate, homomenthyl salicylate, 2-ethylhexyl salicylate, salicylate of triethanolamine, 4-isopropylbenzyl salicylate, 4-ter-butyl-4'-methoxy-dibenzoylmethane, 4-isopropyl-dibenzoylmethane, menthyl anthranilate, 2-ethylhexyl-2-cyano-3,3 ' -diphenylacrylate, ethyl-2-cyano-3,3'-diphenylacrylate, 2-phenyl benzimidazole 5-sulfonic acid and its salts, 3- (4'-trimethylammonium) -benzyliden-boman-2-on- methylsulfate, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 2,4-dihydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2'- 4,4-hydroxy-dimethoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, α- (2-oxoborn-3-ylidene) -tolyl- acid 4-sulfonic and its salts on 3- (4'-sul fo) benzyliden-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, urocanic acid, 2,4,6-tris- [p- (2'-ethylhexyl-1'-oxycarbonyl) anilino] -1, 3,5-triazine, 2 - [(p- (tert-butylamido) anilino] -4,6-bis - [(p- (2'-ethylhexyl-1'-oxycarbonyl) anilino] -

1,3,5-triazine, 2,4-bis {[4-2-ethyl-hexyloxy)] - 2-hydroxy] -phenyl} -6- (4-methoxy-phenyl) -1, 3,5- triazine; the polymer of N- (2 and 4) - [(2-oxobom-3-yliden) methyl] benzylj-acrylamide, 4,4-bis-benzimidazolyl-phenylen-3,3 ', 5,5'- acid tetrasulfonic acid and its 2,2'-methylen-bis- [6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol] salts. polyorganosiloxanes with a malonate function.

The amount of compound recognized as a filtering agent for ultraviolet radiation, contained in the composition of the invention is of course a function of the desired effect and can therefore vary to a large extent.

Preferably, agents capable of substantially filtering UV A radiation will be used. According to an advantageous embodiment of the invention, the I P UVA (UVA protection index) determined according to the method of the JCIA (Japonese Cosmetic Industry Association, Measurement standards for UVA efficacy. Tokyo, Japan: 1995) will be 5 to 20, preferably 8 to 15.

Advantageously, the filter preparation will have a sun protection factor or SPF (sun protection factor) determined according to the Colipa method (The european cosmetic toiletry and perfumery association (Colipa). Sun protection factor method. Report 94/289. Brussels Belgium, 1994) at least equal to 10 and less than or equal to 60, preferably from 15 to 30.

The filter preparation will thus contain a quantity of UVB and UVA filters so as to combine with a high SPF, an IP UVA also high.

Filters particularly suitable for the implementation of the invention will be chosen from the group comprising 2-ethylhexyl salicylate, 4-ter-butyl-4'-methoxy-dibenzoylmethane, 2-hydroxy-4-methoxybenzophenone-5 -sulfonate, benzene acid 1,4 ~ di (3-methylidene-10-camphosulforιique) and its salts, and mixtures of these compounds.

To give an order of magnitude, the quantity of filtering agents for ultraviolet radiation contained in the composition is in an amount representing from 0.1% to 25% of the total weight of the composition, in particular from 6 to 25%; advantageously it will be at least 8%, and preferably less than or equal to 15% of the total weight of the composition; according to another advantageous embodiment of the invention, the filtering agents are present in an amount representing from 0.5% to 10% of the total weight of the composition.

The agent (s) stimulating the synthesis of melanin can be chosen from:

- analogs of substrates of tyrosinase, a key enzyme in melanogenesis such as tyrosine, L-dopa or L-dihydroxylphenylalanine

activators of the activity or expression of tyrosinase such as forskolin, xanthic bases (theophylline, caffeine), pro-opiomelanocortic peptides (ACTH, alpha-MSH or other agonists of MC1 receptors), diacylglycerols, aliphatic or cyclic diols, psoralens, prostaglandins and the like, activators of protein kinase G NO / cGMP dependent, - activators of transfer of melanosomes to keratinocytes such as serine proteases or receptor agonists BY 2.

Preferably, according to the invention, an extract obtained from a plant, in particular from Burnet (Sanguisorba officinalis), is used, or an extract from at least one plant of the genus Chrysanthemum, particularly of the species Chrysanthemum sinensis.

In fact, surprisingly, the Applicant has demonstrated that such extracts induce a remarkable stimulation of melanogenesis and therefore of browning, even in the absence of notable irradiation by UV A rays. This unexpected effect is much greater. to that obtained with other propigmentants.

The extract of at least one plant of the genus Chrysanthemum can be any extract prepared from any plant material derived from a plant of the genus

Chrysanthemum.

The composition may contain at least one extract of at least one plant of the genus Chrysanthemum obtained from material obtained from a plant cultivated in vivo or derived from culture in vitro. The term “in vivo culture” means any culture of the conventional type, that is to say in soil in the open air or in a greenhouse, or even above ground.

It is thus possible, for example, according to the invention to use an extract of different parts of the plant, leaves, flowers, stems, roots, undifferentiated cells, alone or as a mixture, whether the plant is cultivated in vivo or in vitro.

The selection pressure imposed by the physico-chemical conditions during the growth of plant cells in vitro makes it possible to obtain standardized plant material which is available throughout the year unlike plants cultivated in vivo.

The term “in vitro culture” means all of the techniques known to those skilled in the art which artificially make it possible to obtain a plant or part of a plant.

Preferably, an extract obtained from plant material cultivated in vivo is used, and even more preferably an extract obtained from leaves of plants of the genus Chrysanthemum cultivated in vivo.

The expression “extract of at least one plant of the genus Chrysanthemum” is understood to mean both a crude mixture of parts of the plant roughly reduced to pieces and of the extraction solvent, as well as preparations prepared from the active principles dissolved during the extraction. It will be possible in particular to use extracts prepared according to the techniques described in application FR2 768343, which is incorporated here by reference. A particularly usable extract according to the invention is produced by fine grinding of parts of the plant followed by maceration in the extraction solvent, said solvent preferably being a hydrophilic solvent, and finally by filtration. Obviously the extract according to the invention can be each of the extracts thus obtained used alone or in admixture with one or more of the other extracts. Any extraction method known to a person skilled in the art can be used according to the invention.

Mention may in particular be made of aqueous, alcoholic, in particular ethanolic, extracts, hydroalcoholic extracts. Whatever the form of the extract that it is desired to use, the techniques used to obtain it are those generally described in the prior art and well known to those skilled in the art.

One can also use an extract prepared by the method described in French patent application No. 95-02379.

Thus, in a first step the plant material is ground in a cold aqueous solution, in a second step the particles in suspension are removed from the aqueous solution obtained from the first step, and in a third step the aqueous solution obtained from the second step. This aqueous solution corresponds to the extract.

On the other hand, the first step can advantageously be replaced by a simple freezing operation of the plant tissues (for example at -20 ° C.), followed by an aqueous extraction repeating the second and third steps described above. The extract which can be used according to the invention may undergo successive fractionation stages, with a view to concentrating the active principles. Advantageously, this fractionation will be carried out by a liquid / liquid extraction, the fractions extracted by a hydroalcoholic mixture will preferably be used, eliminating the top fractions.

Whatever the mode of preparation used according to the invention, subsequent steps aimed at promoting conservation and / or stabilization can be added without modifying the very nature of the extract. Thus, for example, the extract obtained can be lyophilized by any conventional lyophilization method. A powder is thus obtained which can be used directly or else mix in an appropriate solvent before use. Preferably according to the invention, an aqueous extract is used. As Burnet extract, use is preferably made, according to the invention, of a dry extract of the root and rhizome of Sanguisorba officinalis which can in particular be obtained in powder form from MARUZEN PHARMACEUTICALS CO., LTD (Burnet Extract Powder).

The amount of compound stimulating the synthesis of melanin contained in the composition of the invention is of course a function of the desired effect and can therefore vary to a large extent.

To give an order of magnitude, the compound stimulating the synthesis of melanin contained in the composition is in an amount representing from 0.01% to 15% of the total weight of the composition and preferably in an amount representing from 0.5% to 5% , in particular from 1 to 5% of the total weight of the composition.

The compositions according to the invention may also contain artificial tanning and / or browning agents for the skin (self-tanning agents), such as for example dihydroxyacetone (DHA).

The compositions of the invention may also comprise conventional cosmetic adjuvants in particular chosen from fatty substances, organic solvents, thickeners, softeners, antioxidants, opacifiers, stabilizers, emollients, hydroxy acids, anti-aging agents. foam, moisturizing agents, vitamins, perfumes, preservatives, surfactants, fillers, sequestrants, propellants, alkalizing or acidifying agents, colorants, or any other ingredient usually used in cosmetics, in particular for manufacturing of sunscreen compositions in the form of emulsions.

The fatty substances can consist of an oil or a wax or their mixtures, and they also include fatty acids, fatty alcohols and fatty acid esters. The oils can be chosen from animal, vegetable, mineral or synthetic oils and in particular from petroleum jelly oil, paraffin oil, silicone oils, volatile or not, isoparaffins, fluorinated and perfluorinated oils. Likewise, the waxes can be chosen from animal, fossil, vegetable, mineral or synthetic waxes known per se.

Among the organic solvents, mention may be made of lower alcohols and polyols.

The thickeners can be chosen in particular from crosslinked acrylic acid homopolymers, guar gums and modified or unmodified celluloses such as hydroxypropylated guar gum, methylhydroxyethylcellulose, hydroxypropylmethyl cellulose or even hydroxyethylcellulose.

Of course, those skilled in the art will take care to choose this or these optional additional compounds and / or their quantities in such a way that the advantageous properties, in particular the level of photoprotection, intrinsically attached to the binary association in accordance with invention are not, or not substantially, altered by the planned addition (s).

The compositions of the invention can be prepared according to techniques well known to those skilled in the art, in particular those intended for the preparation of emulsions of oil-in-water or water-in-oil type, or alternatively anhydrous compositions.

This composition can be presented in particular in the form of a simple or complex emulsion (O / W, W / O, O / W / O or W / O / W) such as a cream, a milk, a gel or a cream gel, powder, solid composition, flexible pasta and optionally be packaged as an aerosol and be in the form of a foam or spray.

When it is an emulsion, the aqueous phase thereof may comprise a nonionic vesicular dispersion prepared according to known methods (Bangham, Standish and Watkins. J. Mol. Biol. 13, 238 (1965), FR2315991 and FR2416008).

The cosmetic composition of the invention can be used as a composition for protecting the human epidermis or the hair against ultraviolet rays, as a sunscreen composition or as a make-up product.

When the cosmetic composition according to the invention is used for the protection of the human epidermis against UV rays, or as an antisun composition, it may be in the form of a suspension or of dispersion in solvents or fatty substances, in the form of nonionic vesicular dispersion or alternatively in the form of an emulsion, preferably of the oil-in-water type, such as a cream or a milk, in the form of an ointment, gel, cream gel, stick, flexible pasta, aerosol or spray foam.

When the cosmetic composition according to the invention is used for protecting the hair, it can be in the form of a shampoo, lotion, gel, emulsion, nonionic vesicular dispersion and constitute, for example, a composition to be rinsed, applying before or after shampooing, before or after coloring or bleaching, before, during or after perming or straightening, a styling or treating lotion or gel, a lotion or gel for brushing or setting, a composition of perm or hair straightening, coloring or bleaching.

When the composition is used as an eyelash, eyebrow or skin makeup product, such as epidermis treatment cream, foundation, lipstick stick, eyeshadow, blush, mascara or liner also called "eyeliner", it can be in solid or pasty, anhydrous or aqueous form, such as oil in water or water in oil emulsions, nonionic vesicular dispersions or even suspensions.

As an indication, for the sunscreen formulations in accordance with the invention which have an oil-in-water emulsion type support, the aqueous phase (comprising in particular hydrophilic filters) generally represents from 50 to 95% by weight, preferably from 70 to 90% by weight, relative to the whole of the formulation, the oily phase (comprising in particular lipophilic filters) from 5 to 50% by weight, preferably from 10 to 30% by weight, relative to the whole of the formulation, and the emulsifier (s) from 0.5 to 20% by weight, preferably from 2 at 10% by weight, relative to the entire formulation.

Another subject of the invention is the use of the combination of at least one agent which filters ultraviolet radiation and one or more agents stimulating the synthesis of melanin, in a composition or for the preparation of a bronzing filter composition.

The subject of the invention is also a method of cosmetic treatment of the skin intended to protect it against the effects of UV rays while giving it a natural tan consisting in applying to the skin an effective amount of a product as defined above. or a cosmetic composition comprising it.

The following examples and compositions illustrate the invention without limiting it in any way. In the compositions the proportions indicated are percentages by weight.

Example 1: Preparation of an extract of Chrysanthemum sinensis:

Leaves of plants of Chrysanthemum sinensis grown in a greenhouse are removed and dried for 48 hours in a ventilated oven at a temperature of 45 ° C.

The dried leaves are then reduced to powder by grinding on a knife grinder of the Culatti type.

The powder obtained is sieved on a grid whose holes have a diameter of 1 mm. It is this sifted powder that is used for the preparation of the extract.

Protocol 1:

The powder is mixed with an aqueous extraction solvent consisting of DMEM / F cell culture medium 12.3: 1 sold by the company Life Technologies, at a concentration of 5 grams of dry powder per 100 ml of solvent . The mixture is stirred for 4 hours at room temperature. The mixture is then centrifuged at 1000 rpm for 8 minutes and the supernatant is removed and subjected to two identical centrifugation / removal cycles.

The last supernatant removed is filtered through a 0.22 μm Millipore type filter under aseptic conditions in order to be sterilized and stored at a temperature of 4 ° C. until use.

Protocol 2:

The powder is mixed with sterile demineralized water having a pH of 6.5 at a concentration of 2.5 grams of dry powder per 100 ml of water. The mixture is stirred for 30 minutes at room temperature. The mixture is then filtered on GFD membranes sold by the company Whatmann having a porosity of 0.7 μ. The filtrate obtained is then filtered on a 0.22 μm Nalgene type filter under aseptic conditions in order to be sterilized and stored at a temperature of 4 ° C. until use.

Protocol 3: The previous protocol is carried out by replacing the water with an aqueous extraction solvent consisting of DMEM / F 12 cell culture medium, 3: 1 sold by the company Life Technologies.

Protocol 4: The extract obtained in Protocol 2 is lyophilized at 30 ° C after freezing at -20 ° C. The powder obtained is used directly. EXAMPLE 2 Measurement of the Photoprotective and Propigmenting Effect of the Association of Mexoryl SX® (3.3 '- (1,' phenylenedimethylidyne) bis (7,7dimethyi-2-oxobicyclo [2,2,1] heptane-1 -methanesulfonicacid) with either an extract of Burnet or an extract of Chrysanthemum sinensis obtained by protocol 2 of Example 1.

The photoprotective and propellant effect of the association was tested on co-cultures of normal human keratinocytes / melanocytes according to the method described in patent FR95 06491 by evaluation of melanogenesis induced by UV. The rate of melanin synthesis is evaluated by the incorporation of thiouracil labeled with C ¹⁴ . It is related to the amount of protein.

Normal human keratinocytes (NHK) and normal human melanocytes (NHM) are grown from foreskin skin. Both types of cells are amplified and stored frozen. Eight days before the test, each of the cell types is returned to culture. The keratinocytes are cultured according to the method described by Rheinwald and Green (Cell (1975) 6, 331-334) on feeder cells (fibroblasts 3T3) in the growth medium Green 7F (DMEM / F12 3: 1, fetal calf serum (Gibco) 10%, adenine 0.18 mM, epidermal growth factor EGF 10 ng / ml, hydrocortisone 0.4μg / ml; insulin 5μg / ml, isoproterenole 10μM, transferrin 5μg / ml, triiodothyronine, 2nM). The melanocytes are amplified in the M2 medium (Olsson, M.J. et al., Lancet (1992) 340, 981). The media are changed every two days.

3 days before the test, 250,000 normal human keratinocytes and 80,000 normal human melanocytes are mixed and seeded with wells of 24-well plates (Costar type) and cultured three days in keratinocyte growth medium (Green 7F) without red of phenol .. During the following four days, the culture medium is replaced daily by the UV medium (DMEM / F12 3: 1 without phenol red, calf serum defined 2% (HyClone), EGF 10 ng / ml, factor β-type fibroblastic growth (βFGF) 10 ng / ml) The UV pigmentation induction is carried out by solar simulation (SSR) using a 1000 Watts Oriel Xenon solar simulator including a 280-400nm dichroic filter (Oriel, model 81035) and a WG 320 filter of Schott brand with a cut-off wavelength of 311nm (corresponding to a thickness of about 1.5mm).

The cell cultures are irradiated once a day for 4 days in a phosphate buffer solution (PBS).

The propigmenting molecules are brought into contact with the cells in PBS during the irradiation and added to the culture medium (UV medium) after the irradiation.

Burnet extract is tested at 0.005%. It is prepared in a stock solution at

0.5% in a solvent (Dimethylsulfoxide DMSO) which is added to the thousandth in PBS and in the UV medium. The final concentration of the solvent in the culture medium is therefore 1/1000.

The extract of Chrysanthemum sinensis obtained according to protocols No. 2 + 4 is tested at 1%.

Tyrosine, which serves as a positive control, is tested at 500 μM.

Mexoryl SX® is tested at 8%

INGREDIENTS

AMOUNT

WATER 60

TEREPHTHALYLIDENE DICAMPHOR SULFONIC ACID 8

PROPYLENE GLYCOL 8

GLYCERINE 7

SILICONE OIL 8

C12-15 ALKYL BENZOATE 2

STEARYL ALCOHOL 1,5

PVP / EICOSENE COPOLYMER 1

SODIUM STEAROYL GLUTAMATE 1 STEARIC ACID 1.5

PEG-100 STEARATE 0.75

GLYCERYL STEARATE 0.75

CARBOMER 0.3

HYDROXYPROPYL METHYLCELLULOSE 0.1

TRIETHA OLAMINE QS pH 7

CONSERVATIVE QS

QS PERFUME

After each exposure to UV, the formulations containing the solar filter are applied at the rate of 1.4 mg / cm ² on a quartz slide on which there is a strip of Transpore® according to a method derived from that used for determining the indices. in vitro sunscreen described by Diffey and Robspn (J Soc Cosmet Chemists (1989) 300, 230-235). The assembly is placed above the co-cultures for the duration of the irradiation.

After irradiation, the cells are incubated in UV medium containing 1 μCi / ml of thiouracil labeled with C ¹⁴ .

Measurement of melanogenesis: The following controls are carried out:

- control culture: No product tested

- solvent control culture: the solvent of the tested products is added

- positive control for stimulation of melanogenesis: tyrosine 500 μM;

24 hours after the last UV irradiation, the cells are rinsed in phosphate buffer. The proteins are precipitated using 5% trichloroacetic acid (TCA) and washed in order to remove the free radioactivity. The cells are lysed overnight at 40 ° C. using a proteinase K solution at 100 μg / ml in Tris HCl-triton-EDTA buffer. 5 μl of total extract are taken and transferred to a 96-well plate (Wallac) for the protein assay which is carried out with the MicroBCA * Protein Assay Reagent kit (Pierce).

The rest of the extract, i.e. 950 μl, is filtered on a DEAE Filtermat filter. After rinsing, the filter covered with the solid glitter "Meltilex" is transferred to a plate. Radioactivity is counted using the Wallac counter. The results are expressed as a percentage of the control control, or of the solvent control if the product is dissolved in a solvent other than water, according to the formulas:

(14CP / qty protein P) - (14CT / qty protein T)

X 100

(14CT / qty protein T)

and (14CP / mg protein P) - (14CS / mg protein S)

X 100

(14CS / qty protein S)

in which: ⁴ CP is the average of the disintegrations per minute (dpm) thiouracil ¹⁴ C on 3 similar wells treated with a product (P);

Qty protein P is the average amount of protein in the corresponding wells (in milligrams),

¹⁴ CT is the average of ¹⁴ C thiouracil dpm over 3 similar control wells (T); . Qty protein T is the average amount of protein in the corresponding wells (in milligrams),

¹⁴ CS is the average of the thiouracil dpm ¹⁴ C over 3 similar wells solvent controls (S); protein S quantity is the average of the quantities of protein in the corresponding wells (in milligrams). Results:% variation in melanin synthesis compared to control (cells not treated with the product and not irradiated)

products

Irradiation only (SSR) 222

Irradiation only + solvent 251

Tyrosine 500 μM 40

0.005% Burnet Extract (solvent) 110

Chrysanthemum sinensis extract 1% 500

SSR + Mexoryl SX® 8% 15

SSR + solvent + Mexoryl SX® 8% 36

SSR + Tyrosine 500 μM 382

SSR + 0.005% Burnet Extract (solvent) 466

SSR + Chrysanthemum sinensis extract 1% 588

SSR + Tyrosine 500 μM + Mexoryl SX® 8% 74

SSR + 0.005% Burnet Extract + Mexoryl SX® 8% (solvent) 460

SSR + Chrysanthemum sinensis extract 1% + Mexoryl SX® 8% 428

A = ¹⁴ CthioU / protein qty (% / control)

The variations in melanin synthesis measured under the different conditions give rise to the following classification:

SSR + MSX <SSR + MSX + propigmentant <or = SSR + propigmentant

Conclusions:

These results show that, in combination with a filter in high concentration, a propigmenting product allows the restoration of browning (synthesis of melanin).

EXAMPLE 3 Bronzing and Filtering Composition to Apply to the Skin Containing a 1% Burnet Extract %

Water 60 terephthalylidene dicamphor sulfonic acid 8 propylene glycol 8 glycerin 7 silicone oil 8

Alcohol 12-15 alkyl benzoate 2 stearyl 1.5 pvp / eicosene copolymer 1 sodium stearoyl glutamate 1 stearic acid 1, 5 peg-100 stearate 0.75 glyceryl stearate 0.75 carbomer 0.3 hydroxypropyl methylcellulose 0.1 triethanolamine qs pH 7

Conservative qs

Perfume qs

A dry extract of the root and rhizome of Sanguisorba officinalis is added to this composition, which can in particular be obtained in powder form from MARUZEN PHARMACEUTICALS CO., LTD (Burnet Extract Powder), so that its concentration in the finished product is from 1 %.

Example 4: Bronzing and filtering composition to be applied to the skin containing chrysanthemum sinensis at 1%

% Water 60 terephthalylidene dicamphor sulfonic acid 8 propyleneglycol 8 glycerin 7 silicone oil 8

Alcohol 12-15 alkyl benzoate 2 stearyl 1, 5 pvp / eicosene copolymer 1 sodium stearoyl glutamate 1 stearic acid 1, 5 peg-100 stearate 0.75 glyceryl stearate 0.75 carbomer 0.3 hydroxypropyl methylcellulose 0.1 triethanolamine qs pH 7

Preservative qs Perfume qs

A chrysamthemum sinensis extract obtained according to FR 2768343 is added to this composition, so that its concentration in the finished product is 1%.

Claims

1.: Product composed by at least the combination of at least one agent filtering ultraviolet radiation and at least one agent stimulating the synthesis of melanin.

2.: Product according to claim 1, characterized in that the filtering agent for ultraviolet radiation is chosen from organic filters and / or mineral filters.

3.: Product according to any one of claims 1 or 2, characterized in that the agent filtering ultraviolet radiation is an organic filter chosen from cinnamic derivatives, salicylic derivatives, camphor derivatives, derivatives of triazine, benzophenone derivatives, dibenzoylmethane derivatives, β, β-diphenylacrylate derivatives, p-aminobenzoic acid derivatives, filter polymers and filter silicones.

4. Product according to any one of claims 1 or 2, characterized in that the agent filtering ultraviolet radiation is a mineral filter chosen from pigments or nanopigments of metallic oxides coated or not, such as nanopigments for example titanium oxide (amorphous or crystallized in rutile form and / or anatase), iron, zinc, zirconium or cerium.

5.: Product according to any one of claims 1 to 4, characterized in that the agent filtering ultraviolet radiation is a sun filter active in UV-A and / or UV-B,

6.: Product according to any one of claims 1 to 5, characterized in that the filtering agent for ultraviolet radiation is chosen from p-aminobenzoic acid, oxyethylenated p-aminobenzoate (25mol), p- 2-ethylhexyl 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, 4-isopropyl-dibenzoylmethane, - menthyl anthranilate, 2-ethylhexyl-2-cyano-3,3'-diphenylacrylate, rethyl-2-cyano-3,3'-diphenylacrylate, l 2-phenyl benzimidazole 5-sulfonic acid and its salts, 3- (4'-trimethylammonium) -benzylidèn-bornan-2-on-methylsulfate, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone -5-sulfonate, 2,4-dihydroxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4,4'dimethoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, α- (2-oxobom-3-ylidene) -tolyl-4-sulfonic acid and its salts 3- (4'-sulfo) benzyliden-bornan- 2-one and its salts,

Ie 3- (4'methylbenzylidene) -d, l-camphor, 3-benzylidene-d, l-camphor, benzene acid 1, 4-di (3-methylidene-10-camphosulfonic) and its salts, urocanic acid, 2,4,6-tris- [p- (2'-ethylhexyl-1 '-oxycarbonyl) anilino] -1, 3,5-triazine,

2 - [(p- (tert-butylamido) anilino] -4,6-bis - [(p- (2'-ethylhexyl-1'-oxycarbonyl) anilino] -

1,3,5-triazine, 2,4-bis {[4-2-ethyl-hexyloxy)] - 2-hydroxy] -phenyl} -6- (4-methoxy-phenyl) -1, 3,5- triazine; the polymer of N- (2 and 4) - [(2-oxoborn-3-ylidèn) methyl] benzylj-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.

7.: Product according to any one of claims 1 to 6, characterized in that the agent filtering ultraviolet radiation is in an amount representing from 0.1% to 25% of the total weight of the composition.

8.: Product according to any one of claims 1 to 7, characterized in that the agent filtering ultraviolet radiation is in an amount representing

0.5% to 10% of the total weight of the composition.

9.: Product according to any one of claims 1 to 8, characterized in that the agent stimulating the synthesis of melanin is chosen from analogues of substrates of tyrosinase such as tyrosine, L-dopa or L - dihydroxylphenylalanine, activators of the activity or expression of tyrosinase such as forskolin, xanthic bases (theophylline, caffeine), pro-opiomelanocortic peptides (ACTH, alpha-MSH or other agonists of MC1 receptors) , diacylglycerols, aliphatic or cyclic diols, psoralens, prostaglandins and the like, activators of protein kinase G NO / cGMP dependent, or activators of transfer of melanosomes to keratinocytes such as serine proteases or agonists of PAR-2 receptors.

10.: Product according to any one of claims 1 to 9, characterized in that the agent stimulating the synthesis of melanin is an extract of Burnet (Sanguisorba officinalis) or also an extract of at least one plant of the genus Chrysanthemum .

11.: Product according to any one of claims 1 to 10, characterized in that the agent stimulating the synthesis of melanin is an extract of at least one plant of the species Chrysanthemum sinensis.

12.: Product according to any one of claims 1 to 11, characterized in that the agent stimulating the synthesis of melanin is in an amount representing from 0.01% to 15% of the total weight of the composition.

13.: Product according to any one of claims 1 to 12, characterized in that the agent stimulating the synthesis of melanin is in an amount representing from 1% to 5% of the total weight of the composition.

14.: Composition comprising at least one product as defined in any one of claimsl to 13.

15.: Use in a composition or for the preparation of a composition of at least one product as defined in any one of claimsl to 13.

16.: A method of cosmetic treatment of the skin intended to protect it against the effects of UV rays while giving it a natural tan consisting in applying to the skin an effective amount of a cosmetic product or composition according to one of claims 1 to 15.