WO2009010587A1

WO2009010587A1 - Use of at least one extract of the aerial portions of fireweed and/or evening primrose for preparing a composition for restoring the barrier function of keratinised or mucous tissues

Info

Publication number: WO2009010587A1
Application number: PCT/EP2008/059474
Authority: WO
Inventors: Marc Schwaller
Original assignee: Marc Schwaller
Priority date: 2007-07-19
Filing date: 2008-07-18
Publication date: 2009-01-22
Also published as: FR2918882A1; FR2918882B1

Abstract

The invention relates to the use of at least one extract of the aerial portions of fireweed and/or evening primrose for preparing a composition for restoring the barrier function of keratinised tissues, such as the skin or the nails, or mucous tissues, or for preventing and/or treating alterations of the barrier function of said keratinised or mucous tissues.

Description

Use of at least one extract of the aerial parts of the polyilobe and / or evening primrose for the preparation of a composition intended to restore the barrier function of keratinized tissues or mucous membranes

The present invention relates to the use of at least one extract of aerial parts of the Epilobe and / or Evening Primrose for the preparation of a composition intended to restore the barrier function of keratinized tissues such as the skin, the hair , and nails, or mucous membranes, or to prevent and / or treat alterations of the barrier function of said keratinized tissues or said mucous membranes. The composition may be a drug, a dermatological or dermo-cosmetic composition, or a food or nutraceutical composition (dietary supplement).

While most life forms depend on the structure of their membranes for their existence, this appears to be particularly true in the skin of terrestrial mammals. One of the vital functions associated with the skin of these animals is to regulate the amount of water lost in the environment. This crucial function is associated with a particular structure called stratum corneum, which is the outermost layer of the epidermis.

The stratum corneum is composed of the stacking of ten layers of highly differentiated cells that have lost their nucleus and whose contents have been heavily loaded into a fibrous protein called keratin. These cells, called corneocytes, are maintained together by extracellular protein structures called corneo-desmosomes. The corneo-desmosomes of adjacent cells are interconnected by hydrophobic bonds between glycine loops rich in hydrophobic amino acids.

The corneocyte layers are surrounded by an extracellular matrix of lipid nature having a multilamellar structure. The model generally chosen to represent the structure of the stratum corneum is that of a brick wall whose mortar represents the extracellular lipid matrix and the bricks represent the corneocytes. The multilamellar lipid structure is the only continuous phase between the two ends of the stratum corneum.

Several biophysical studies have shown that the lipid domains of the stratum corneum constitute an essential barrier to loss of water and vis-à-vis the penetration of small molecules from the external environment. Thus, when an extraction of lipids from the stratum corneum by an organic solvent is carried out, a considerable increase (of the order of a factor of 1000) of the permeability with respect to water is observed. The role of stratum corneum lipids in the regulation of water loss seems to be perfectly established.

The permeation of water molecules through lamellar lipids takes place through free spaces created during fluctuations in the assembly of hydrocarbon chains. It was also possible to show that if the lipid composition had some influence on the barrier function, it was not the only regulating factor.

Characterization techniques such as infrared spectrometry, ESR spectrometry, X-ray diffraction, and more recently Raman spectroscopy, have shown that mammalian stratum corneum lipids exhibit a reversible phase transition between a "solid state" And a "liquid state". This transition between the physical state of the lipids of the stratum corneum appears to be perfectly correlated with the permeability with respect to water.

Indeed, the higher the proportion of lipids present in solid form, the greater the barrier function is important. Thus, it is the conformational state of the lipids which constitutes the essential element of the regulation of the aqueous permeability of the stratum corneum. In the physiological state, the water permeability of the stratum corneum is much less important than it would be if all the lipids were present in the liquid state. Indeed, the lipids present in the solid state, because of the high compaction of their carbon chain, considerably slow down the diffusion rate of the water molecules, which will have to travel average distances that have been estimated to be 50 times more important than the actual thickness of the stratum corneum.

In some circumstances, whether of extrinsic or intrinsic origin, the barrier function of the skin may be insufficient. One of the main consequences will be an increase in water loss that could eventually lead to widespread dehydration. A second consequence, directly associated with this state, is the increased risk of penetration of exogenous (xenobiotic) molecules into the body, which can lead to various toxicological or immunological disorders. On the other hand, the alterations of the barrier function are generally associated with defects in comfort and cutaneous aesthetics, the skin becoming rougher, duller, more scaly, less supple.

It has been believed for years that the solution to the above problems was the application to the skin of fatty substances of various origins which were supposed to retain the water of the skin by their occlusive nature. It is now known that such an occlusion causes water to accumulate in the corneocytes of the outer layers of the epidermis. The turgor that results tends to weaken their structure and function (We can make an image of this mechanism by observing the whitish appearance of the skin under a dressing that has been kept for several days). Ultimately, the use of occlusive fat products creates a real vicious circle in which the epidermis seems to have to be permanently protected.

Other more modern methods consist in attempting to increase the content of the skin in biomimetic agents intended to mimic the action of cutaneous hydration factors or synthetic ceramides. Although very attractive in principle, these methods only lead to improvements of low intensity and are very slow to set up. It should also be remembered that the alteration of the barrier function of the stratum corneum is more controlled by the state of the organization of its constituents than by a qualitative or quantitative change in its composition. We understand why the supply of biomimetic molecules is not more effective.

More invasive methods, such as peeling or dermabrasion, aim to promote the exfoliation of the most damaged outermost layers of the stratum corneum in order to accelerate their renewal by the internal layers supposed to have a better structure. These methods generally require to be performed under medical supervision and the aggressive nature of the agents used exposes a significant risk of more or less significant side effects.

Even more invasive, the surgical methods, aimed at retightening the skin or injecting fillers, are reserved only for the most severe cases and do not seem to be adapted to the greatest number of people, both because of the problems related to their therapeutic indication, the therapeutic risks incurred and their cost.

Under these conditions, there is still a real need to have a simple, fast, effective and inexpensive method, to restore the barrier function of the epidermis, for many preventive or curative applications, medical or cosmetic, aimed in particular to improve the barrier function of the skin and its aesthetic appearance.

Like the epidermis and the hair, the nails constitute a specialized keratinised tissue. The nails can be weakened by disturbances of internal origin, such as alterations of keratin chains of genetic origin. Other attacks have an external origin and come most often from the use of aggressive cleaning products, contact with organic solvents, mechanical aggression or excessive contact with water.

Finally, the nails and the junction zone between the nail and the skin constitute a privileged place for the penetration into the body of bacterial and especially fungal pathogens, which can lead to relatively frequent infectious diseases such as whitlow and mycoses.

As a result, several approaches have been used to try to strengthen the structure of the nails and strengthen their barrier function. The majority of these approaches involve covering the nails with an outer protective layer that is generally obtained from synthetic polymers. However, it seems that no technique currently allows to strengthen the own structure of the nail and even less to strengthen its barrier function.

As in the case of the skin, there is still a real need to have a simple, fast, effective and inexpensive method to strengthen the structure and improve the appearance of the nails.

In addition to skin and nails, hair is also a keratinized tissue. The visible part of the hair, the capillary stem, has a diameter that varies between 50 and 100 micrometers. At the level of the inner body of the stem, the cortex, a fibrous protein, keratin, is organized into protofibrils composed of four chains of keratin. At the peripheral level, the cuticle plays a protective role. These are flat cells in the form of scales which, in the normal state, are in perfectly joined form.

As in the case of the epidermis, it is an intercellular cement composed of sterols, fatty acids and ceramides that ensures the impermeability and cohesion of the hair fiber.

If the strength of the hair comes mainly from the structure of its cortex, its fragility comes mainly from its cuticle. Indeed, if we consider that the hair lengthens, on average, of 1 cm per month, the end of a hair of 30 cm is 2 years and half during which it underwent many aggressions related to the environment and the use of hygiene products or capillaries more or less aggressive.

Thus, when we observe the surface of a hair by scanning microscopy, we observe signs of aging that are becoming more important the further we are from the root. Near the root, the scales appear perfectly joined and resemble perfectly joined slates of a new roof. The further one goes to the periphery, the more the scales rise and separate. These defects of organization of the cuticle, observed mainly with the capillary ends, involve in particular: a defect of reflection of the light: the hair becomes dull; a greater roughness: the hair becomes rough; an increase in the interaction with the adjacent hair: the hair becomes difficult to comb (entanglement); at the end of the hair, the almost total disappearance of the cuticle causes a division of the cortex: the hair becomes forked.

In an attempt to overcome these disadvantages, the hair cosmetics industry has developed several types of products. Among natural products, there are vegetable oils whose essential action is to supplement a lack of sebum on the surface of the hair. These fatty substances exert their action only on the surface of the hair and have no real restorative action. Synthetic products include polymers that have an external "sheathing" action, but do not restore the original structure found in healthy hair.

A more modern approach has been to synthesize bio-mimetic ceramides whose structure is inspired by natural ceramides present in the cuticle. This approach is very attractive in the case where the structural defect can be associated with a deficiency identified in one or more ceramide (s). However, in the majority of cases, the initial defect is not due to a deficiency in one or more ceramide (s), but rather to a change in the physical state of organization of the constituents of the cuticle under the influence external aggressions (linked in particular to climatic phenomena or related to the use of too aggressive hair products).

As in the case of skin and nails, there is still a real need for a simple, fast, effective, fast and inexpensive method, to restore the structure of the damaged hair to improve the appearance, the softness and make them easier to comb.

The applicant has surprisingly discovered that extracts of aerial parts of plants from the family of onagraceae showed an intense and immediate action of restoration of the barrier functions of the skin and had a positive action for pharmaceutical applications, dermatological, cosmetic, or food. The two main plants which are the subject of the invention are the pilchard (Epilobium angustifolium) and the evening primrose (Onagra biennis), and more particularly the aqueous extracts, obtained by maceration of the aboveground parts of these crushed plants in hot water or other solvents of similar polarity, followed by filtration.

The Willow herb is a plant traditionally used to treat various digestive and prostate disorders (LESUISSE et al., 1996, J. Nat Prod, Volume 59 (5) page 490).

Evening primrose is a plant traditionally used, orally or topically, to treat the skin, but the part of the plant traditionally used is the seed, and more particularly the oil extracted from the evening primrose seeds.

The evening primrose seed oil, which is particularly rich in unsaturated fatty acids, is typically obtained by pressing the seeds. This oil is generally incorporated into dietary or cosmetic compositions for the skin.

However, the aerial parts of the Evening Primrose, such as flowers, leaves, or stems, are generally considered to be plant wastes that are rejected. and which are not valued, especially in the pharmaceutical, dermatological or cosmetic fields.

The extracts of the aerial parts of Epilobe or Evening primrose according to the present invention are natural products, and prove to be compounds, cosmetically, pharmaceutically, dermato logically and nutraceutically acceptable, non-aggressive, neither toxic nor irritating to the skin , hypoallergenic, and moisturizers for the skin. In addition, these compounds are obtained by conventional extraction methods, and are commercially available.

Advantageously, the extract according to the present invention does not leave a greasy feel on the skin, unlike the majority of creams for the body. In addition, the effect of improving the protective skin barrier function appears very rapidly after application to the body of the extract according to the present invention or a composition containing such an extract. The effect of improving the barrier function typically occurs after a few minutes, preferably from 1 to 30 minutes, for example from 3 to 10 minutes, after application of the product to the skin, hair, nails, or lips . This effect of improving the protective cutaneous barrier function also appears very rapidly, typically after a few minutes, advantageously from 1 to 30 minutes, for example from 3 to 10 minutes, following the oral administration of the extract. according to the present invention or a composition containing such an extract.

Moreover, the effect obtained by the extract according to the present invention is persistent and lasts a certain time after administration of the extract. Typically, the restoration effect of the protective cutaneous barrier function is still present a few hours after the application of the extract. In addition, such an effect persists even after taking a bath or a shower, which is not the case for most body creams.

The subject of the present invention is therefore the use of at least one extract of the aerial parts of the Epilobe and / or Evening Primrose for the preparation of a composition intended to restore the barrier of the mucous membranes such as the oral mucosa or gingival, or keratinized tissues such as skin, hair, and nails, or to prevent and / or treat alterations of the barrier of said mucous membranes or said keratinized tissues.

For the purposes of the present invention, the term "aerial parts" is intended to mean those parts of plants that grow out of the ground, with the exception of seeds. These include, in particular, leaves, fruits, flowers, petals, twigs, stems, and mixtures thereof.

Advantageously according to the present invention, the aerial parts of the Fireweed and / or Evening Primrose are chosen from the group consisting of leaves, stems, and mixtures thereof.

The extract of the aerial parts of the Willowweed and / or Evening Primrose can be obtained by various methods.

In a particular embodiment of the present invention, the extract is obtainable by the process comprising at least the following succession of steps: grinding the aerial parts of the Willowweed and / or Evening primrose, maceration aerial parts of the crushed plants in the form of powders in at least one polar solvent such as water or a solvent of polarity close to that of water, advantageously at a temperature below 80 ^° C., filtration or centrifugation to remove the plant solid particles, and possibly partial or total evaporation of the solvent.

In a particularly advantageous manner, the extract according to the invention is an aqueous extract.

An alcoholic extract according to the present invention is not used because the alcoholic extracts of the aerial parts of the Willow heron or Evening primrose do not contain the active fraction of the plants which makes it possible to obtain an action on the barrier function of the plants. keratinized tissues. On the contrary, by macerating the aerial parts of the Willow heron or Evening primrose in alcohol, the active fraction of the plants is not only not extracted, but it precipitates.

The solvent used for extraction (by maceration) is thus typically water or an organic solvent of polarity close to that of water. Typically, one macerates between Ig and 80Og, advantageously between 10Og and 500g, more advantageously between 200g and 400g, of plant powder (dry extract) per liter of solvent such as water.

The extraction is advantageously carried out at a temperature below 80 ⁰ C, typically between 50 and 80 ⁰ C, of the order of 60 to 70 ⁰ C for example. The extraction (by maceration) is preferably carried out for a period of between 30 minutes and 3 hours, typically of the order of 1 to 2 hours.

According to one particular characteristic of the present invention, the extract is present in a concentration of between 5 and 100%, advantageously between 20 and 90% by weight, typically between 30 and 60% by weight, relative to the total weight of the composition. .

Advantageously according to the present invention, the active fraction of the extract according to the present invention is selectively precipitated in water / alcohol mixtures (such as ethanol), so as to obtain an extract rich in active fraction.

By the term "active fraction of the extract" is meant in the sense of the present invention the fraction of the aqueous extract which is insoluble when said aqueous extract is precipitated in 70 to 99% of alcohol (such as ethanol). Said aqueous extract is prepared beforehand by macerating the aerial parts of Epilobe and / or Evening primrose, advantageously milled, in hot water, typically at a temperature below 80 ^° C., of the order of 50 to 70 ^° C. vs.

For the purposes of the present invention, the term "extract rich in active fraction" means an extract containing at least 50% by weight, typically between 50 and 90% by weight, for example of the order of 60 to 80% by weight. % by weight, based on the total weight of the extract.

Advantageously according to the present invention, the composition is a pharmaceutical, dermatological, cosmetic, nutraceutical or food composition, and may comprise any suitable vehicle or excipient, which is acceptable from the pharmaceutical, dermatological, cosmetic or nutraceutical point of view, as well as conventional additives, known to those skilled in the art.

In a particularly advantageous manner according to the invention, the extract of the aerial parts of the Epilobe and / or Evening Primrose is used as the only active ingredient within the composition, in particular to restore the barrier function of the keratinized tissues. or mucous membranes, or to prevent and / or treat alterations in the barrier function of keratinized tissues or mucous membranes.

Advantageously, the composition according to the present invention makes it possible to restore the barrier function of keratinized tissues in an extremely rapid manner. The action is, in fact, typically observed only a few minutes after its administration. This rapidity of action suggests that it is a modification of the properties of the keratinized tissues induced by the composition, in particular the extract, and not an action on the renewal of the keratinized tissues. Indeed, if the composition acted on the process of renewal of the keratinized tissues, the restoration of the barrier function would appear only after several days, or even weeks.

Advantageously, the composition according to the present invention is intended to protect keratinized tissues against external aggressions such as allergen-type chemicals or pathogens of the bacterial, viral or fungal type.

In particular, the extract according to the present invention, which makes it possible to improve the cutaneous barrier function, makes it possible to protect the bodies from external aggression, whether of microbiological origin (bacteria, yeasts, molds). and viruses), animal, or chemical (pollution). The extract according to the present invention makes it possible in particular to reduce the penetration of chemical agents originating from environmental pollution through the skin.

The composition according to the present invention is also advantageously intended to prevent or treat excess skin desquamation, psoriasis, ichthyosis, atopic dermatitis, or pruritus, especially of the skin or scalp.

The composition according to the present invention can also be used to prevent or treat snoring, typically by exerting a lubricating action on the uvula, or to prevent or treat canker sores or gingivitis, typically by exerting a protective action vis-à-vis vis ulcerations of the oral or gingival mucosa. For these uses, the composition is advantageously administered orally.

According to a particular characteristic of the present invention, the composition is a dermatological or pharmaceutical composition, and may comprise any suitable vehicle or excipient, dermatologically or pharmaceutically acceptable.

In a particular embodiment of the present invention, the composition is formulated to be administered topically. The composition according to the present invention can thus be applied to the skin, on the scalp or the hair, on the lips, or on the nails. It may be in the form of cream, ointment, milk, lotion, ointment, serum, paste, gel, mousse, or emulsion.

In another particular embodiment of the present invention, the composition is formulated to be administered orally. The composition may thus be in the form of pellet, mouthwash, mouthwash, capsule, capsule, tablet, granule, chewing paste, gum, oil or oily jelly.

In this embodiment, the composition according to the invention is advantageously used to treat the mucous membranes, such as the oral and gingival mucosa, in particular for the treatment or prevention of canker sores or gingivitis.

Advantageously according to the present invention, the composition is titrated so as to allow the administration of a daily dose of 100 mg to 1000 mg, preferably 200 mg to 500 mg, of extract per day.

The subject of the present invention is also the cosmetic use of at least one extract of aerial parts of the Epilobe and / or Evening primrose to restore the mucosal barrier such as the oral or gingival mucosa, or keratinized tissues such as than the skin, the hair, and the nails, or to prevent and / or treat the alterations of the barrier of said mucous membranes or said keratinized tissues.

In this particular embodiment of the present invention, the aerial parts of the Willowweed and / or Evening Primrose are as defined above.

The extract is typically described above and prepared according to the method described above.

The extract is advantageously present at a concentration of between 5 and 100%, advantageously between 20 and 90% by weight, typically between 30 and 60% by weight, relative to the total weight of the cosmetic composition. According to one particular characteristic of the present invention, the composition is a cosmetic, nutraceutical or food composition, and may comprise any suitable vehicle or excipient, which is acceptable from a cosmetic or nutraceutical point of view, as well as conventional additives known to man. of career.

In this particular embodiment of the present invention, the extract is typically administered topically, preferably in the forms mentioned above.

The extract according to the present invention can be advantageously incorporated in body care products such as solid or liquid soaps, skin lotions, shampoos, hair lotions.

In the case of hygiene products, the extract allows a restoration of the alteration of the barrier functions of the skin induced by the surfactants (such as lauryl sulfate) present in these products.

The extract according to the present invention can also be administered orally, preferably in the forms mentioned above.

Advantageously according to the present invention, the extract is used to improve the microstructure or the micro-relief of keratinized tissues such as the skin, advantageously to prevent or treat the micro-fine lines of the skin, or to soften or smooth the skin or the hair, to improve the luminosity of the complexion of the skin or the hair especially after exposure to the sun, or to improve the shine or the suppleness of the hair or nails.

The extract according to the present invention makes it possible to restore the barrier function of the skin while ensuring a smoothing and flattening function of the cutaneous microrelief, in particular fine lines of the skin.

The extract can also be advantageously used to prevent or treat the cracking of the lips.

The extract according to the invention can also be used to protect keratinized tissues against external aggressions such as cold, wind, detergents or other aggressive products such as exfoliants or paint solvents, cements, plasters, to treat or prevent the formation of blisters or the appearance of heating of the skin, especially in the feet and hands, to treat or prevent the appearance film, to strengthen the strength of the hair or the hardness of the nails, or to prevent the formation of forks in the hair.

The extract can thus be advantageously used when the skin is subjected to peeling or exfoliation techniques. The peel is a technique to achieve a rejuvenation of the appearance of the skin by exfoliation of the upper layers of the epidermis. Such a technique requires the use of relatively aggressive agents. The extract according to the present invention can be used as a post-peeling agent, since it makes it possible to neutralize the aggressive action of the agents used for the peeling (exfoliating agents such as alpha-hydroxy acids or phenol) and to obtain a faster repair of the lesions induced by these agents.

The extract according to the invention may also be advantageously used to prevent or treat snoring, or to prevent or treat the mucous membranes, such as the oral and gingival mucosa, in particular for the treatment of canker sores or gingivitis.

Since the extract makes it possible to smooth the skin and smooth out the cutaneous microrelief, the extract according to the invention can also be advantageously used to improve the performance of swimmers, in particular competition swimmers, by reducing the coefficient of friction between skin and water.

The following examples are intended to illustrate the invention without in any way limiting its scope.

EXAMPLE 1 Preparation of extracts of aerial parts of Epilobe and Evening primrose according to the invention

The extracts were made according to the following method:

reduction in fine particles of stalks of willow or evening primrose in a mill, extraction by maceration in water at 80 ⁰ C, introducing 200 g of plant powder per liter of water, and maintaining at this temperature for 2 hours cooling of the reaction medium at 60 ^° C., followed by filtration on a 100 μm filter of porosity, conditioning of the filtrate in glass bottles.

We thus obtain an extract of stalks of Willowweed on the one hand and an extract of stalks of Evening primrose on the other hand.

EXAMPLE 2 Study of the Activity of Plant Extracts According to the Invention on the Physiology and Biophysical Properties of the Stratum Corneum

In order to study the action of the extracts according to the invention on the barrier function of the skin, measures of hydration and insensible perspiration were carried out with 30 volunteers (20 women and 10 men) complaining chronically of skin dryness and roughness.

Each volunteer was applied to a defined area of each forearm 200 .mu.l of each extract prepared according to Example 1. Thus, the two extracts were tested on each volunteer on a different area for each extract.

A sample of 200 .mu.l of each extract was poured gradually and spread over the skin area delimited.

Four tests were performed 15 min after the application of the extract on each cutaneous zone: measurement of cutaneous hydration by corneometry, the result being expressed in arbitrary unit ranging from 0 to 120, measurement of the PIE, the result being expressed in g (water) / cm ² (skin) / hour, measurement of the skin microrelief, made from the comparison of silicone impressions made on the same skin area before and after treatment, and followed by a profilometric laser analysis. The results are expressed as a percentage of reduction of the surface of the fine lines detected, determination of the state of organization of the lamellar lipids of the stratum corneum carried out by spectral analysis by Raman Spectroscopy, in the window between 730 and 1170 cm. ¹ , to determine the relative proportion of lipids present in the solid and liquid state. Table 1 below shows the results obtained as a percentage improvement, this percentage being calculated from the average of the results of each test on the 30 volunteers.

Table 1:

Extracts Hydration PIE Microrelief Lipids Solid State

Epilobe + 15.2% - 28, 8% - 46.3% + 40, 1%

Evening primrose + 14.2% - 26, 3% - 45.2. % + 39, 7%

Four key points emerge from this study:

1) the increase in cutaneous hydration is well correlated with the decrease of the PIE, which confirms that these extracts act by reinforcing the barrier effect of the stratum corneum,

2) the improvement of the cutaneous microrelief is very important with the 2 extracts; which is probably related not only to the moisturizing effect observed but also to a compaction effect of the upper layers of the epidermis,

3) the improvements observed in terms of hydration and smoothing of the cutaneous microrelief are associated with a clear increase in the level of compaction of the hydrophobic chains of the lipids of the stratum corneum,

4) the rapidity of the appearance of beneficial effects (less than 10 minutes after application), which can not be attributed to a biochemical mechanism, but which is consistent with a shift in thermodynamic equilibrium involving the conformation of the lipid side chains stratum corneum.

In addition, an efficacy study was conducted with 72 people (58 women and 14 men) agreeing to participate in this test, regardless of their age and skin type.

A bottle of evening primrose extract (200 g / l expressed in dry plant before extraction), prepared according to example 1, was given to all the volunteers, and they were asked to apply the product on the cutaneous zone which they considered to be the driest and more wrinkled of their body then to fill, 10 min after the first application (this delay was chosen as being slightly greater than the drying time of the aqueous extract on the surface of the skin), a self-evaluation form including a double visual analogue scale graduated from 1 to 10, the value 1 corresponding on the one hand to the lack of moisturizing effect and on the other hand flattening of fine lines, and the value 10 to a maximum effect of hydration of a part and flattening of fine lines on the other hand.

At the end of this study, the results were excellent because 90% of the volunteers said they found a moisturizing effect and 97.2% a smoothing effect of the cutaneous microrelief. The average score by all volunteers was respectively 9.2 / 10 for the moisturizing effect and 9.7 / 10 for the anti-wrinkle effect.

It should also be noted that the best scores were obtained on dry and rough skins, and that the worst scores were obtained on the already well hydrated and smooth skins before application.

Most of the volunteers continued using the extract for several days or even weeks, which allowed them to report: a persistence of the moisturizing and anti-wrinkle effect of at least 48 hours and persisting the most often 72 hours, a persistence of moisturizing effect even after showering or bathing, an improvement in the luminosity of the complexion of the skin after application of the product, a perfect tolerance, no reaction of irritation, inflammation been reported by any of the volunteers.

A number of exploratory tests were also conducted informally with volunteers. They were: either volunteers with no particular expectation in terms of cosmetics but who agreed to test the product prospectively, or volunteers complaining of a lack of appearance in their skin, their nails or of their hair.

The results obtained made it possible to identify in particular the following activities: At the level of the skin: a very fine anti-wrinkle effect, an activity of improvement of softness of the skin and especially of the luminosity of the complexion, a strong attenuation of the skin desquamation after a exposure to the sun, a protection of the skin against external aggressions has been reported by many volunteers: less sensitivity of the hands and face to cold and wind and improvement of the quality and beauty of the skin of the hands after repeated exposure to detergents and other aggressive solvents of paint, cement or plasters, an improvement of the skin condition in pathologies such as psoriasis, ichthyosis and atopic dermatitis, in the feet and hands, a softening but also preventive effect of the skin. appearance of heating and blister formation, neutralization of the action of exfoliating agents and obtaining a faster repair of the lesions induced by these agents: use as postpeeling agent, an attenuation of the penetration of chemical agents from environmental pollution through the skin.

At the level of the hair:

Several volunteers reported a clear effect in terms of softness, suppleness, shine and strength of hair that became less brittle and also easier to comb.

At the level of the nails:

Several volunteers reported improvement in nail polish and hardness. At the level of the mucous membranes:

Several volunteers reported a net attenuation effect of mouth ulcers and gingivitis in the oral and gingival mucosa.

In addition, a comparative test was performed on the same volunteers between a moisturizing cream marketed in France and an aqueous extract made from the aerial parts of Onagre. The volunteers applied the cream on one forearm (or one leg) and the extract on the other forearm (or the other leg).

The responses of the volunteers revealed the following differences: the side treated with the aqueous extract did not show a greasy feel, unlike the cream, the moisturizing effect was almost immediate, since it appeared less than 3 minutes after application of the extract, whereas it was noticeable that 1 to 2 hours after the application with the cream, when the greasy touch was gone, the moisturizing effect disappeared completely 4 to 6 hours after the application of the cream, while it was still very clear 12 hours after the application of the extract, the moisturizing effect of the cream disappeared as soon as the volunteer took a bath or a shower, while this effect persisted with the extract watery evening primrose.

Claims

1. Use of at least one extract of aerial parts of the Willowweed and / or Evening Primrose for the preparation of a composition intended to restore the barrier function of keratinized tissues such as skin, hair, and nails , or mucous membranes, or to prevent and / or treat alterations in the barrier function of said keratinized tissues or said mucous membranes.

2. Use according to claim 1, characterized in that the aerial parts are chosen from the group consisting of leaves, stems, and mixtures thereof.

3. Use according to claim 1 or 2, characterized in that the extract is obtainable by the process comprising at least the following sequence of steps: grinding the aerial parts of the Willow heron or Evening primrose, maceration of the ground aerated parts in at least one polar solvent such as water, preferably at a temperature below 80 ⁰ C, filtration or centrifugation to remove plant solid particles, optionally partial or total evaporation of the solvent.

4. Use according to any one of claims 1 to 3, characterized in that the extract is present at a concentration of between 5 and 100%, advantageously between 30 and 60% by weight, relative to the total weight of the composition .

5. Use according to any one of the preceding claims, characterized in that the composition is intended to protect the keratinized tissues against external aggressions such as allergens-type chemicals or pathogens of the bacterial, viral or fungal type, or to prevent or treat excess skin desquamation, psoriasis, ichthyosis, atopic dermatitis, or pruritus, especially of the skin or scalp.

6. Use according to any one of the preceding claims, characterized in that the composition is intended to prevent or treat snoring, or to prevent or treat canker sores or gingivitis.

7. Use according to any one of the preceding claims, characterized in that the composition is formulated to be administered topically or orally.

8. Use according to any one of the preceding claims, characterized in that the composition is a dermatological or pharmaceutical composition.

9. Cosmetic use of at least one extract of aerial parts of the Willowweed and / or Evening Primrose to restore the barrier function of keratinized tissues such as skin, hair, and nails, or mucous membranes, or for to prevent and / or treat the alterations of the barrier function of said keratinized tissues or said mucous membranes.

10. Cosmetic use according to claim 9, characterized in that the aerial parts are chosen from the group consisting of leaves, stems, and mixtures thereof.

11. Cosmetic use according to claim 9 or 10, characterized in that the extract is obtainable by the process comprising at least the following sequence of steps: grinding the aerial parts of the willowberry or evening primrose maceration of the ground aerated parts in at least one polar solvent such as water, advantageously at a temperature below 80 ⁰ C, filtration or centrifugation to remove the plant solid particles, optionally partial or total evaporation of the solvent.

12. Cosmetic use according to any one of claims 9 to 11, characterized in that the extract is present in a cosmetic composition, at a concentration of between 5 and 100%, advantageously between 30 and 60% by weight, relative to to the total weight of the cosmetic composition.

13. Cosmetic use according to any one of claims 9 to 12, for improving the microstructure or the micro-relief of keratinized tissues such as the skin, advantageously for preventing or treating micro-fine lines of the skin, or for softening or smoothing the skin or the hair, to improve the luminosity of the complexion of the skin or the hair especially after exposure to the sun, or to improve the shine or the suppleness of the hair or nails.

14. Cosmetic use according to any one of claims 9 to 12, for protecting the keratinized tissues against external aggressions such as cold, wind, detergents or other aggressive products of the exfoliating type, for treating or preventing the formation of blisters or the appearance of heating of the skin, especially in the feet and hands, to treat or prevent the appearance of dandruff, to strengthen the strength of the hair or the hardness of the nails, or to prevent the formation of forks in the hair.

15. Cosmetic use according to any one of claims 9 to 12, for preventing or treating snoring, or for preventing or treating canker sores or gingivitis.

16. Cosmetic use according to claim 13, for improving the swimmers' performance by reducing the coefficient of friction between the skin and the water.

17. Cosmetic use according to any one of claims 9 to 16, characterized in that the extract is intended to be administered topically or orally.