WO2012172199A1

WO2012172199A1 - Composition based on camellia japonica and polygonum hydropiper for protecting the skin

Info

Publication number: WO2012172199A1
Application number: PCT/FR2012/050677
Authority: WO
Inventors: Nadine Leconte; Jacques Leclere
Original assignee: Laboratoire Nuxe
Priority date: 2011-03-31
Filing date: 2012-03-29
Publication date: 2012-12-20
Also published as: FR2973246A1; FR2973246B1; EP2691074A1

Abstract

The invention relates to a composition that can be used in dermatology and/or cosmetics. Said composition comprises an effective quantity of an extract of Camellia japonica and an extract of Polygonum hydropiper, combined. The invention can be applied to cosmetic and dermatological compositions for the treatment or the prevention of signs of skin ageing and stretch marks.

Description

COMPOSITION BASED ON CAMELLIA JAPONICA AND POLYGONUM HYDROPIPER FOR SKIN PROTECTION

The present invention relates to a novel cosmetic and / or dermatological composition intended to ensure the protec ^¬ of the epidermis, and more particularly a composition containing extract of Camellia japonica having a protective effect on the skin, particularly an effect prevention and treatment of stretch marks.

The skin is a real organ comprising a plurality of integrated layers, from super ficial ^¬ layer, the epidermis, to the deeper layers, the dermis and hypodermis, each has specific properties enabling the whole to react and adapt to the conditions of his environment.

The epidermis, composed mainly of keratinocytes (90% of epidermal cells), melanocytes (2 to 3% of epidermal cells) and Langerhans cells, has a variable thickness depending on the different parts of the body. Since it constitutes the outer layer of the skin, the epidermis plays a fundamental role in ensuring the protection and maintenance of good trophicity. This is why many compositions have been developed to protect and improve its functions, including strengthening its elasticity and firmness.

The dermis, thicker, solid, rich in nerves, blood vessels and sweat glands, consists mainly of collagen, elastin and proteoglycans. These three types of molecules are synthesized by dermal fibroblasts. Collagen fibers, which repre ^¬ tent 70% of the dry weight of the dermis, ensure the mechanical strength and texture of the skin, elastin is responsible for the elasticity, and proteoglycans play a major role structure and hydration of the skin. Other cells such as macrophages and leucocytes are also present in the dermis layer. The hypodermis, which is the deepest layer of skin, contains lipid-producing fat cells so that the subcutaneous tissue makes a fat layer that protects muscles, bones, and internal organs from shock.

The skin, and each of its constituent layers, can suffer damage caused by internal or external causes, for example aging and excessive stretching.

The aging of the skin is manifested by signs such as the formation of more or less deep and extensive wrinkles, in addition to a loss of elasticity and thinning. The appearance of the first wrinkles is a phenomenon that can be aggravated by physical or chemical aggression from pollution, exposure to ultraviolet rays or lifestyles that accelerate skin aging.

A balance between degradation and tissue synthesis exists in normal subjects. Thus, the extra ^¬ cellular matrix can be degraded by metalloproteinases which essentially fall into three main groups are the collagenases, gelatinases and stromelysins. For example, collagenase fibroblast (MMP-1) is a collagenase, gelatinase A (MMP-2) and gelatinase B (MMP-9) are gelatinases, and stromelysin-1 (MMP-3) and matrilysin (MMP-7) are stromelysins. Excess metallo-proteinases cause degradation of biomolecules such as collagen, proteoglycan and gelatin, which can have adverse effects on epidermal tissue. Also, many studies have been devoted to the inhibitory properties of metalloproteinases of various substances.

In addition to aging, another cause of skin damage is the formation of stretch marks, or striae distensae or striae atrophicae, which are small ridges or chippers ^¬ rures elongated, often in length between about 5 and 15 cm, due to an atrophy of the cutaneous network which does not withstand significant distensions to which the skin can be subjected under particular conditions.

This skin condition is mainly found in pregnant women in the abdomen, but it can also occur in obese people in the case of rapid weight gain. It has long been considered as caused by a mechanical effect causing the distention of the skin, but it is now estimated that it may also be due to hyperfunctioning of the adrenal glands (Cushing's syndrome). Treatment with corticosteroids may result in the formation of stretch marks by disrupting the biosynthesis of dermal fibroblasts, resulting in a decrease in collagen, elastin and proteoglycan formation, partial inhibition of hyaluronic acid synthesis, and chondroitin sulfate, as well as impaired protein production. The formation of stretch marks is generally accompanied by a phenomenon ^¬ flam matory. These effects result in rupture of the conjunctive tissue.

Stretch marks can affect relatively large areas of the skin, appearing as purplish-red streaks that evolve over time to a lighter color. They provide an unsightly effect that can have negative psychological consequences in some subjects and it is therefore important to be able to develop treatments that can prevent, mask or eliminate them.

It is sometimes proposed to treat stretch marks with a laser but the results are often unsatisfactory. Various treatments of essentially cosmetic nature, acting on the epidermis, have also been used, in order to mask stretch marks, for example by means of compositions based on organic silicon, amino acids such as proline, polyunsaturated and unsaponifiable oils. vitamins with antiradical action, derivatives of Centella asiatica, or retinoic acid derivatives such as tretinoin, etc. These treatments can at best mitigate the unsightly effects of stretch marks but do not make them disappear.

Thus, patent application WO 0019974 describes the use of soy peptides and tripeptides consisting of glycine, histidine and lysine for the prevention and treatment of stretch marks on the skin. US Pat. No. 7,429,386 describes the treatment of stretch marks by local administration of botulinum toxin intradermally.

Many plant extracts have been proposed in cosmetic and dermatological compositions capable of providing effects useful in various applications.

For example, FR-A-2 848 116 discloses a cosmetic and / or dermatological composition based on Siegesbeckia extract acting as an inhibitor of matrix metalloproteinases, in combination with lipopeptides for the treatment and prevention of wrinkles and loss of elasticity of the skin. The application WO-A-2007/144518 describes the use of a mimosa seed extract, in particular from the Acacia dealbata, Acacia farnesiana or Acacia decurrens species, which has the effect of strongly promoting the synthesis of collagens.

In the case of treatment of stretch marks, it is desirable to have plants likely to have a general activity on free radicals, on the protection of the extracellular matrix (metalloproteinases) and on the protection of elastin (effect anti-elastasic). Such activity can indeed annihilate one of the main causes of the formation of stretch marks mentioned above while strengthening the elasticity and firmness of the skin.

Camellia japonica, commonly known as camellia, is a plant of the family Theaceae native to East and Southeast Asia, including Japan, Korea and China, in the form of a shrub that can reach 6 to 7 m. Among the many species of Camellia genus, Camellia japonica is well known for the quality and beauty of its red or pink flowers. In traditional Chinese medicine, the seeds of Camellia japonica have been used for their anti-inflammatory activity, and the flowers for their haemostatic effect in the treatment of hematemesis. Studies have shown the presence of saponins in fruits and seeds, triterpenoids in the roots, and flavonol glycosides in the leaves, exhibiting antioxidant properties, as described by K. Onodera et al., Biosc. Biotech. Biochem. 70, 1995-1998 (2006). The plant is also rich in polyphenols and contains an aromatic essence. The anti-herpes activity of Camellia japonica leaves is described in US 5,411,733. Patent FR 2815862 describes an anti-aging composition combining an extract of Camellia (for example C. sinensis) and a carotenoid such as - and β-carotene and lycopene. This association would have potentiated effects of stimulation of collagen synthesis, but no experimental results are provided.

Polygonum hydropiper, commonly known as water pepper, is a plant of the family of polygonaceae rich in tannins and flavonic derivatives. It also contains an essential oil and sesquiterpene aldehydes which give it its burning flavor justifying its common name of water pepper. It has been described as having hemostatic, diuretic and hypotensive activity. Polygonum hydropiper root extracts would have activity against fertility, as written by S.K. Garg et al., J. Reprod. Fert. 29, 521-423 (1972). The antibacterial activity and hydrating effect of Polygonum hydropiper (or Persicaria hydropiper) was also mentioned by Kim Jung Eun et al., Korean J. Microbiology and Biotechnology, vol. 38, pp. 112-115 (2010).

Young Heui Kim et al., "J. Cosmetic Science" vol. 58, pp. 19-33 (2007) describes the antiradical, anti-elastase and anti-MMP effect of several plants from Jeju Island, South Korea, including Camellia japonica (leaves) and Persicaria hydropiper (whole plant), which inhibit the MMP-1 in fibroblast cells and could therefore be potential actives of anti-aging compositions. However, the combination of these two substances is not suggested, nor are their effects in the treatment of stretch marks.

Although numerous dermatological and cosmetic compositions have been proposed, there is still a need to be able to have new alternative topical compositions that make it possible to protect the skin by effectively combating the signs of cutaneous aging and against stretch marks, and in particular topical compositions with basis of appropriate plant extracts from more particu ^¬ larly of plants known for their properties in favor of such activity.

Studies by the applicant have shown that it is possible to protect the skin and act effec ^¬ cement against the signs of skin aging and against stretch marks, using topical compositions based on extracts of a plant of the species Camellia japonica, with extracts of a plant of the species Polygonum hydropiper. Studies have shown that extracts of Camellia japonica have an effective action against wrinkles of skin aging and against stretch marks, both preventive and curative, and that this action is potentiated by the addition of plant extracts from Polygonum hydropiper.

The compositions of the invention are distinguished in that they comprise an extract of a plant of the species Camellia japonica in association with an extract of a plant of the species Polygonum hydropiper in an amount effective to provide a protection of the epidermis against the signs of skin aging and against stretch marks, as well as acceptable carriers and excipients in dermatology and cosmetology.

The present invention therefore relates to a new cosmetic and / or dermatological composition based on Camellia japonica, and more particularly based on Camellia japonica extract, in association with extracts of Polygonum hydropiper.

Such a composition has excellent properties used in cosmetics and dermatology for the protection of the skin, not only against the signs of skin aging but also against stretch marks.

The present invention also relates to a topical composition based on the combination of an extract of Camellia japonica and an extract of Polygonum hydropiper for the prevention and treatment of signs of skin aging and stretch marks.

The present invention also relates to a non-therapeutic cosmetic method for preventing and combating the signs of skin aging and stretch marks on the skin, comprising applying to the areas of the skin concerned a topical composition containing an effective amount of the combination of extract of Camellia japonica and Polygonum hydropiper extract according to the present invention.

The invention also relates to a pharmaceutical composition based on an extract of Camellia japonica and an extract of Polygonum hydropiper for the protection of the epidermis and more particularly the prevention and treatment of stretch marks.

The compositions according to the present invention distin ^¬ Guent in that they comprise an extract of Camellia japonica in combination with an extract from Polygonum hydropiper in an amount effective to provide skin protection, as well as carriers and excipients acceptable in dermatology and in cosmetology.

Thus, the topical compositions of the invention based on extracts of Camellia japonica and extract of Polygonum hydropiper can be advantageously used in dermatology and cosmetology for the treatment or prevention of signs of skin aging and stretch marks. The tests carried out by the applicant have shown that among the various parts of the plant, it is preferable to use the aerial parts and in particular the leaves. The species Camellia japonica is readily available and leaf conservation does not usually raise technical difficulties.

The extracts of Camellia japonica used in the compositions according to the present invention are preferably obtained in the form of an aqueous extract from the aerial parts of the plant previously dried, crushed to a fine powder that is left to macerate in water for about 12 to 14 hours.

According to an advantageous embodiment, the extract that can be used in the invention is obtained by maceration from crushed and reduced Camellia japonica leaves into a powder which is left to macerate in water in a powder / water ratio of 40% by weight. The product is then decanted, expressed and filtered.

The aqueous extract of Camellia japonica is in the form of a yellow to amber liquid, with a characteristic odor, soluble in water and in ethanol, characterized by:

pH between 3.4 - 4.0

density 0.990 - 1.050

refractive index 1.325 - 1.345

dry matter (%) 0,5 - 2,5

polyphenols (% / dry matter) 1,7

The amount of polyphenols per 100 g of extract is between 0.0085 and 0.0425.

The extracts of Polygonum hydropiper used in

The invention is obtained from the aerial parts of the plant, preferably in the form of aqueous extracts after maceration of the previously dried and milled plant. According to a preferred embodiment, the tips (leaves and stems) or the leaves of Polygonum hydropiper, which are dried, crushed and reduced to powder, are used. which is macerated in water, the powder / water ratio being 40%, about 24 hours. After decantation, expression and filtration, the filtrate is atomized and the powder obtained is diluted to 50% with maltodextrin.

The aqueous extract of Polygonum hydropiper is in the form of a beige-to-brown powder of characteristic odor, soluble in water, characterized by: pH (1% solution) between 4.9 - 6, 9

density 0.990 - 1.050

refractive index 1.325 - 1.345

dry matter (%) 0,5 - 2,5

gallic acid (HPLC) presence

polyphenols (% / dry matter) 4,4

The extracts used in the compositions of the invention are in the range of 0.05 to 2.0% for Polygonum hydropiper and 0.1 to 10.0% for Camellia japonica based on the total weight of the composition. . The extracts may be blended to be incorporated into the composition and the amount of mixture used is generally between 0, 1 and 12% by weight relative to the total weight of the compo sition ^¬.

The extracts of Camellia japonica leaves and the extracts of Polygonum hydropiper included in the compositions according to the present invention have shown, in vitro tests, protective effects of the epidermis, and more particularly:

an activity on metalloproteinases showing a protective and regenerating effect on collagen and elastin;

a significant anti-elastase activity, implying protection of elastin ensuring greater firmness of the skin and protection against stretch marks;

an important anti-radical effect ensuring effective protection of the cells against the effects of stress.

The tests were carried out using samples assayed at 0.5% Polygonum piper extract, 5% Camellia japonica, and a combination of the two extracts on human fibroblasts cultured epidermis and reconstituting ^¬ killed (Skinethic ^®).

The results, detailed below, have highlighted the protective effect without harmful side effects, and in particular:

a significant effect, potentiated by the combination of the two extracts, on the expression of metalloproteinases 1 (MMP1), 2 (MMP2) and 9 (MMP9) making it possible to stimulate the regeneration of collagen and elastin;

a significant effect of reducing elastase at the level of human fibroblasts in culture, with a potentiation of the effect by the combination of the two extracts, showing the effect of protection against stretch marks;

an anti-radical effect both under physiological conditions and under conditions of induction by hypoxanthine / xanthine oxidase, showing the effectiveness on the protection of cutaneous cells under the effect of stress which is a triggering factor of the stretch marks formation.

The results are explained in the examples below and demonstrate the potentiation of the effects of each of the components since, at equivalent dose, the results procu ^¬ res by the association are higher than the average of the results of the two components.

The compositions according to the invention may contain, in addition to an extract of Camellia japonica leaves and an extract of Polygonum hydropiper, secondary active agents which advantageously complement their activity, and which are compatible, that is to say, not capable of reacting on each other. others or to mask or limit their respective effects. More particularly, the secondary active agents may be chosen from a mimosa seed extract and a marigold extract that favorably affect the stimulation of neoformed collagens, Centella asiatica, monomethylsilanol, proline, or butter. of Shea. The composition according to the invention may comprise, for example, between 0.1 and 2% by weight of Polygonum piper extract, between 0.1 and 6% by weight of Camellia japonica extract, and, where appropriate, between 1 and and 5% by weight of mimosa seed extract and / or between 2 and 6% by weight of Centella asiatica, and / or between 0.5 and 2% by weight of monomethylsilanol and proline relative to the total weight of the composition. According to a preferred form, these concentrations are respecti vely ^¬ 0.2 to 1% by weight of extract of Polygonum hydropiper, 1 to 6% by weight of extract of Camellia japonica, 2 to 5% by weight of extract of mimosa seeds and between 3 and 5% by weight of Centella asiatica relative to the total weight of the composition.

As indicated above, the compositions of the invention may comprise between 0.1% and 10% by weight of Camellia japonica leaf extract, as defined above, relative to the total weight of the composition, and preferably between 1 and 6% by weight. The concentration of Polygonum hydropiper extract is generally between 0.05 and 2.0%, and preferably between 0.1 and 1.0%.

The choice of the concentration of each component in the composition may be made according to the utili zation ^¬ envisaged. For prolonged protective treatment, lower doses, in the form of milk or cream dosed at about 1 to 6% (total of the two components), are preferably used, while spot treatment may require higher doses, for example for example a serum dosed between 6 and 12%, where, preferably, the doses of extracts of Camellia japonica and Polygonum hydropiper are higher.

Thus, these topical compositions can be used advantageously in dermatology and cosmetology for the treatment or prevention of signs of skin aging as well as for the prevention and treatment of stretch marks.

The combination of Camellia japonica extract and Polygonum hydropiper extract according to the present invention supplemented if necessary with extracts of mimosa seeds and extracts of Centella asiatica as indicated above, used under normal conditions of use for 20 to 30 consecutive days, to treat stretch marks, demonstrated excellent skin tolerance.

The compositions according to the present invention may be presented in the pharmaceutical forms classi ^¬ cally used for topical application, that is to say in the form of lotion, gel, emulsion (especially cream or milk), mask, ointment, nanocapsules, liposomes or transdermal patches, containing compatible and pharmaceutically acceptable excipients and common carriers. They are preferably used in the form of creams, milk serum and lotion.

These forms of topical administration are prepared by the usual techniques, and for example, in the case of a cream, by dispersion of a fatty phase in an aqueous phase to obtain an oil-in-water emulsion, or conversely to prepare a water-in-oil emulsion. In the case of creams, it is preferred to use lamellar structure emulsions containing little or no ethoxylated products.

In the case of nanocapsules and liposomes, it may be advantageous to use an aqueous extract, preferably a hydroglycolic extract.

The topical compositions according to the invention may comprise excipients suitable for external topical administration, in particular dermatologically and cosmetologically acceptable excipients. Such excipients suitable for formulation are well known to those skilled in the art and include in particular penetrating agents such as ethoxydiglycol, phytantriol, octyl dodecanol and escin; thickeners such as natural gums and synthetic polymers; emollients and surfactants such as cetearyl octanoate, isopropyl myristate, cetearyl isononanoate, dimethicone, cyclomethicone, polyglyceryl 3-diisostearate, hydrogenated polyisobutene, cetyl alcohol, cetyl palmitate, cetyl phosphate; emulsifiers; the conser ^¬ vateurs such as phenoxyethanol, methyl paraben (methylparaben), ethyl para-hydroxybenzoate (ethylparaben) and Phenonip® combination of phenoxyethanol and parabens; dyes; the perfumes ; etc.

Other ingredients may be used in the compositions: moisturizing agents such as propylene glycol, glycerine, butylene glycol, sodium salt of pyrrolidone carboxylic acid (PCA sodium), and also antioxidant vitamins such as vitamin E, for example tocopherol acetate or tocotrienol, vitamin C, natural polyphenols. It is also possible to add skin conditioning agents such as nylon and boron nitride to the composition, as well as agents for protecting against ultraviolet rays, and for example hydrophilic or lipophilic UV-A and UV-B sunscreens. , chosen from benzophenone or a benzophenone derivative such as 2-hydroxy-4-methoxy-benzophenone (Eusolex® 4360), or a cinnamic acid ester and more particularly octyl methoxymethylate (Eusolex® 2292) 2-ethylhexyl methoxycinnamate (Parsol MCX®), or a cyano-β, β-diphenylacrylate such as octocrylene (Eusolex® OCR), 4-methylbenzylidene camphor (Eusolex 6300®), and dibenzoylmethane derivatives such as 4-isopropyl dibenzoylmethane (Eusolex 8020), t-butyl-methoxy dibenzoylmethane (Parsol 1789®), and 4-methoxy-dibenzoylmethane. It is also possible to use anti-ultraviolet screen pigments, such as, for example, titanium dioxide, zinc oxide, zirconium oxide or aluminum oxide.

The following examples illustrate the invention in more detail without limiting its scope. In all of the following examples of compositions, parts are by weight unless otherwise indicated. Example 1

According to conventional techniques, an anti-stretch mark milk having the following weight composition is prepared.

Phase A

Sweet almond oil 2.00

Shea butter 2.00

Octyldodecanol 2,00

PEG 6/32 stearate 5.00

Capryl / capric triglycerides 5.00

Tocopherol 0.50

Glycerol ester of Vitamin F 1.00

Glyceryl undecylenate 0.50

Phase B

Demineralised water qs 100.00

Pentylene glycol 5.00

Anisic acid 0.10

Monomethylsilanol 1.00

Hydroxyproline 0.50

Xanthan Gum 0.50

Camellia japonica extract 5.00

Centella asiatica extract 5.00

Polygonum Hydropiper Extract (dry) 0.50

Perfumes 0,50

The extract of Camellia japonica used in the compo sition ^¬ above is an aqueous extract obtained by treating crushed leaves and powdered. The extract of Polygonum hydropiper is a dry extract.

The fatty phase A is heated to 70-75 ° C while the aqueous phase B is heated to 75 ° C, then the two phases are thoroughly mixed with stirring. The extracts and perfumes are added to the mixture at a temperature of 40 ° C and the pH is adjusted to 6.2 by adding potassium hydroxide or citric acid.

The milk having the composition indicated above can be used in application on stretch marks, one to two times per day. Example 2

According to conventional techniques, a firming lotion having the following weight composition is prepared.

Demineralised water qs 100.00

Carboxy vinyl polymer 0,20

Pentylene glycol 5, 00

Butylene glycol-1,3 2,5

Centella asiatica extract 5, 00

Camellia japonica extract 3, 00

Polygonum hydropiper extract 0.20

Proline 1.00

Polyglyceryl amandate-10

Levulinic acid and sodium levulinate 0, 60

Perfumes 0.10

The lotion is prepared by making the polymer gel in water, neutralizing and adding the rest of the components cold.

Example 3

According to a conventional technique, a firming cream having the following weight composition is prepared.

Phase A

Demineralised water qs 100.00

Tetrasodium glutamate diacetate (soil) 0.10

Pentylene glycol 5.00

Sclerotium gum and xanthan gum 0,20

Ci ₂ -Ci ₆ alcohols and palmitic acid

and hydrogenated lecithin 5.00

Phase B

Tocopherol 0.50

Capryl / capric triglycerides 5.00

Squalane 8.00

Octyl dodecanol 5.00

Behenyl alcohol 2.00

Ethyl hexyl glycerine 0.30

Palmitoyl proline 1.00 Phase C

Demineralized water 10.00

Matrixyl 3000 1.00

Monomethylsilanol 2.00

Madecassoside 0.20

Polygonum hydropiper extract 0.50

Camellia japonica extract 5.00

Sodium PCA 1.00

Phase D

Magnesium silicate 0.50

Phase E

Perfumes 0.10

The hydrogenated lecithin is hydrated in water at 75 ° C and then the other ingredients of phase A are added and mixed. Phase B, previously homogenized under a cooled turbine, is added at 78 ° C., then the other phases are successively added at 40 ° C., the mixture is mixed and cooled progressively.

The cream having the composition indicated above is used in application on the face, once a day at bedtime for a period of 1 to 3 months.

Example 4

The in vitro study of the effects of the extracts of Camellia japonica and Polygonum hydropiper used in the present invention on the protection of the epidermis was made on human fibroblasts in culture and on reconstr ^¬ tituified epidermis (Skinethic ^® ), as indicated above.

The fibroblast cultures were established in the usual manner, the fibroblasts having been seeded in 6-well plates at the rate of 10 ⁵ cells per ml, and then incubation for 24 hours.

Four batches of fibroblasts were made for the tests.

Lot 1: control receiving no product

Lot 2: treatment with Polygonum hydropiper 0.5% Lot 3: treatment with Camellia japonica 5%

Lot 4: treatment with the combination Polygonum hydropiper 0.5% + Camellia japonica 5%.

Study of cell viability:

After 24 hours of incubation of the fibroblast cells, the cell viability was determined by the Formazan blue reduction test (MTT test). After incubation of the cells of each batch, the wells containing them are emptied and the cell mat is rinsed with the culture medium. 200 μl of a solution of MTT (3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide) at 5 mg / ml are dispensed into all wells and the plates are incubated. at 37 ° C for 3 hours. The wells are again emptied by inversion, and the cellular mat is fixed for 1 minute with 200 μl of formo-calcium solution. The cells are then lysed and the Formazan blue crystals are dissolved with 200 μl of dimethylsulfoxide. The optical density (OD) of the plates is read, after homogenization of the staining by stirring, using a spectrophotometer at 570 nm, thus making it possible to know the relative quantity of living and metabolically active cells.

The optical density (OD) after 24 hours of contact is shown in the table below.

Cell viability was also monitored using the same batches 1-4 on an in vitro model of reconstituted epidermis (Skinethic ^® ).

Keratinocytes of human origin were inoculated on 0.5 cm ² polycarbonate filters in a defined medium (modified MCDB 153) and supplemented. The cells have been cultured for 14 days at the air / liquid interface, the culture medium being changed every two days. The epidermis thus formed were used in the study from the 17th day of culture.

The test was performed in duplicate for each experimental time of 6 and 24 hours.

Cell viability was assayed by colorimetric reaction with tetrazolium salt (MTT). The color is noted after incubation for 30 minutes at room temperature. A blue-purple color demonstrates the viability of the cells of the epidermis.

The products tested (lots 1, 3 and 4 above) were deposited at a rate of 10 μΐ / cm ² on the reconstituted epidermis for 24 hours. The results are shown in the table below.

Cell viability was also monitored by histological examination. The reconstituted epidermis are fixed in a 10% solution of formaldehyde and included in paraffin blocks. Vertical sections of 4 μm were stained with hematoxylin / eosin and photographed under an optical microscope.

The test showed that the extract of Camellia japonica (5%) and the combination of extracts of Camellia japonica (5%) and Polygonum hydropiper (0.5%) according to the invention, deposited at a rate of 10 μΐ / cm ² , on reconstituted epidermis treated for 24 hours, compared to control epidermis, induced no toxicity. After HES staining, the histological images of the treated epidermis are similar to those of the control epidermis. These results demonstrate the absence of cytotoxicity of the extracts used in the invention.

Example 5

The study of the antiradical effect of the combination of extracts according to the present invention was made on an in vitro model of reconstituted epidermis (Skinethic ^® ).

The antiradical activity was demonstrated by assaying malondialdehyde (MDA) after induction with hypoxanthine / xanthine oxidase. MDA is indeed one of the essential markers of cytotoxicity by oxidative processes and stress, and can therefore provide information on the antiradical activity of a given substance (lipoperoxidation index).

The experimental protocol is the same as that of Example 4 above, with the exception of the constitution of the batches, each test being performed in duplicate after 24 hours of contact of the extracts studied with the reconstituted epidermis.

Lot 1: control epidermis receiving no product

Lot 2: positive control epidermis treated with hypoxanthine / xanthine oxidase.

Lot 3: epidermis treated with vitamin E + hypoxanthine / xanthine oxidase.

Lot 4: epidermis treated with Camellia japonica 5%

Lot 5: epidermis treated with Polygonum hydropiper 0.5% +

Camellia japonica 5%.

Lot 6: epidermis treated with Camellia japonica 5% + hypoxanthine / xanthine oxidase (HXO)

Lot 7: epidermis treated with Polygonum hydropiper 0.5% +

Camellia + hypoxanthine / xanthine oxidase (HXO).

After 24 hours of treatment of the reconstituted epidermis, the cell homogenates are resuspended in:

250 μl of 50 mM Tris buffer, pH 8, containing 0.1M NaCl and

EDTA 20 mM.

25 μΐ of 7% SDS 300 μΐ of HC1 0, IN

38 μΐ of phosphotungstic acid at 1% in water

300 μl of 0.67% thiobarbituric acid in water

After 1 hour of incubation in the dark at 50 ° C. and then cooling in ice water, 300 μl of n-butanol are added to each tube. The tubes are centrifuged at 10,000 g at 0 ° C for 10 minutes. The upper phase is recovered for the determination of MDA.

The MDA is assayed by fluorescence measurement, after separation of the MDA-TBA complex by HPLC chromatography, using a Jasco 821-FI detector with excitation at 515 nm and emission at 553 nm, with eluent methanol: water (40:60 v / v), the pH being adjusted to 8.3 by 1M KOH.

Protein assay is performed according to the Bradford method. The increase in absorbance at 595 nm is propor ^¬ tional to the protein concentration determined using a Unicam 8625 spectrophotometer.

Physiological lipoperoxidation

The results are summarized in the table below.

These results show a significant protection of the extracts of the invention, especially the combination of extracts, vis-à-vis the physiological lipoperoxidation. Lipoperoxidation caused:

The results are summarized in the table below. MDA substance (μΜ / mg protein) MDA variation (%)

Witness 669 ± 33 -

HXO 950 ± 46 +42

Vitamin E + HXO 598 ± 55 -37

C. japonica 5% + HXO 765 ± 61 -19

P. hydropiper 0.5% + 680 ± 50 -28

C. japonica 5% + HXO

HXO = hypoxanthine / xanthine oxidase

These results show a significant protection of the extracts of the invention, and more particularly the combination of extracts, vis-à-vis lipoperoxidation caused by hypoxanthine / xanthine oxidase.

These results demonstrate the antiradical effect of the extracts of the present invention. The comparison of the results obtained with Camellia japonica with or without Polyglut hydropiper shows that the combination potentiates the antiradical effect.

Example 6

The evaluation of the activity of the extracts of the invention on cutaneous regeneration was made by study of the extracellular matrix and assay of metalloproteinases

(MMP1, MMP2 and MMP9) on human fibroblasts in culture.

The fibroblast cultures are identical to those of Example 4 above. The four batches used are the same as in Example 4.

The test was conducted in triplicate after 24 hours of contact of the products studied with human fibroblasts in culture.

The MMP1 assay was performed by the ELISA kit at the level of the culture medium. The results are summarized in the table below. Substance concentration MMP1

(Pg / ml)

Witness 135.4 ± 9.2 -

P. hydropiper 0.5% 112.3 ± 10.0 -17

C. japonica 5% 105, 9 ± 11.7 -22

P. hydropiper 0.5% 98.7 ± 8.5 -27

+ C. japonica 5%

These results show that the two extracts of Camellia japonica and Polygonum hydropiper significantly decrease the expression of metalloproteinase 1 (MMP1) and that this effect is potentiated in the association.

The MMP2 assay was performed by the ELISA kit at the level of the culture medium. The results are summarized in the table below.

These results show that the two extracts of Camellia japonica and Polygonum hydropiper significantly decrease the expression of metalloproteinase 2 (MMP2) and that this effect is potentiated in the combination since each extract causes a very close decrease (-18 and -20% respectively) while the association provides a greater decrease (-24%).

The results of the MMP9 assay, performed by the ELISA kit at the level of the culture medium, are summarized in the table below. Substance concentration MMP9

(Pg / ml)

Witness 97, 8 ± 7.3 -

P. hydropiper 0.5% 82, 6 ± 5, 0 -16

C. japonica 5% 83, 0 ± 6, 1 -15

P. hydropiper 0.5% 75, 0 ± 8, 0 -23

+ C. japonica 5%

These results show that the two extracts of Camellia japonica and Polygonum hydropiper significantly reduce the expression of metalloproteinase 9 (MMP9) and that this effect is potentiated in the association since each single extract causes a very close decrease (-15 and -16% respectively) while the association provides a decrease (-23%) significantly higher.

Example 7

Evaluation of the anti-elastase activity of the extracts of

The invention was made on the same human fibroblasts in culture as those of Example 4 above.

The test was conducted in triplicate after 24 hours of contact of the products studied with human fibroblasts in culture, in the presence of substrate N-succinyl triananine paranothroanilide (SANA). The four batches used are the same as in Example 4 but SANA has been added to batches 1 to 4.

The fibroblasts were seeded in multiwell plates at 10 ⁵ cells per well. They were then incubated with 2% FCS and RMPI for 24 hours, then the FCS was replaced by 0.2% BSA and the cells were incubated for 24 hours in the presence of the products studied. At the end of treatment, the cells were scraped off and the enzymes were extracted from the cell pellet using 0.1% Triton X-100 in Tris-HCl buffer at pH 8, Brij 0, 1% and 20%. μΐ of a solution of SANA (125 mM) in N-ethyl pyrrolidone. The reaction was initiated at 37 ° C. and stopped by addition of 50 μl of acetic acid. The results are summarized in the table below.

These results show that the extracts of Camellia japonica and Polygonum hydropiper significantly inhibit the activity of elastase in human fibroblasts in culture and that this effect is potentiated in the combination of extracts.

Claims

Cosmetic and / or dermatological composition for topical application intended to ensure the protection of the skin, characterized in that it comprises an effective amount of an extract of Camellia japonica and an extract of Polygonum hydropiper.

2. Composition according to claim 1, characterized in that the extract of Camellia japonica is obtained from the leaves of the plant.

3. Composition according to claim 1, characterized in that the extract of Polygonum hydropiper is obtained from the aerial parts of the plant.

4. Composition according to any one of revendica ^¬ tions 2 and 3, characterized in that the extract is in the form of aqueous extract.

5. Composition according to claim 4, characterized in that the extract is obtained by maceration from leaves of Camellia japonica and Polygonum hydropiper reduced to powder.

6. Composition according to any one of the preceding claims, characterized in that the extract of

Camellia japonica is a liquid characterized by:

pH between 3.4 - 4.0

density 0.990 - 1.050

refractive index 1.325 - 1.345

dry matter (%) 0,5 - 2,5

polyphenols (% / dry matter) 1,7

7. Composition according to any one of the preceding revendica ^¬ tions, characterized in that the extract of Polygonum hydropiper is a powder characterized by: pH (1% solution) between 4.9 - 6.9

density 0.990 - 1.050

refractive index 1.325 - 1.345

dry matter (%) 0,5 - 2,5

gallic acid (HPLC) presence polyphenols (% / dry matter) 4,4

8. Composition according to any one of the preceding revendica ^¬ tions, characterized in that it comprises from 0.1 to 2.0% of extract of Polygonum hydropiper and 0.1 to 10.0% of extract of Camellia japonica in relation to the total weight of the composition

9. Composition according to any one of revendica ^¬ tions 1 to 7, characterized in that it further comprises one or more secondary active ingredients selected from a mimosa seed extract, a marigold extract extract, a Centella extract asiatica, monomethylsilanol, proline and shea butter.

10. Composition according to claim 9, characterized in that it comprises between 0.05 and 2% by weight of Polygonum hydropiper extract, between 0.1 and 6% by weight of Camellia japonica extract, between 1 and 5% by weight of mimosa seed extract and / or between 2 and 6% by weight of Centella asiatica, and / or between 0.5 and 2% by weight of monomethylsilanol and proline relative to the total weight of the composition .

11. A non-therapeutic cosmetic method for combating the signs of skin aging and stretch marks on the skin, comprising applying to the areas of the skin concerned a composition containing an effective amount of the topical composition according to any one of claims 1 to 10.

12. A composition comprising an extract of Camellia japonica and an extract of Polygonum hydropiper ^¬ for utili zation in treating skin stretchmarks.