Cosmetic composition comprising as active ingredient an extract of a plant of the genus Isodon

Abstract

The invention relates to a cosmetic composition comprising as sole active ingredient an extract of the aerial parts of a plant of the genus Isodon for use in reducing skin roughness, preventing wrinkles, reshaping the contour of the face, and increasing the density of the dermis. The invention also relates to a method for preparing such a composition. The invention further relates to the use of such a composition for reducing skin roughness, preventing the appearance of wrinkles, reshaping the contour of the face, and increasing the density of the dermis. FIGURE 1 for the abstract:

Description

Title of the invention: COSMETIC COMPOSITION COMPRISING AS ACTIVE INGREDIENT AN EXTRACT OF A PLANT OF THE GENUS ISODON Prior art

[0001] Age, exposure to numerous daily environmental stresses, such as pollution in urban environments, ultraviolet radiation, or even stress and fatigue, and the different lifestyles adopted by the population have effects on the skin. The skin of the face, which is constantly in contact with the external environment, is particularly impacted by these effects.

[0002] There are currently many cosmetic products to combat these effects on the skin. However, a large part of these products include synthetic ingredients, which can have negative effects on the skin, such as irritations or even allergies.

[0003] These products also often include combinations of active ingredients, the number of their ingredients then being able to be significant.

[0004] However, consumer demand for compositions incorporating the minimum of ingredients, and these of natural origin, continues to grow.

[0005] There is therefore a need for new cosmetic compositions intended to combat the harmful effects of age and external stress on the skin which are natural and contain fewer ingredients. The present invention aims to meet this need. Summary of the invention

[0006] This objective is achieved by means of the invention, which relates to a cosmetic composition comprising as sole active ingredient an extract of the aerial parts of a plant of the genus Isodon, for its use in reducing skin roughness, preventing wrinkles, reshaping the contour of the face, and increasing the density of the dermis.

[0007] The inventors have in fact discovered that extracts of only the aerial parts of a plant of the genus Isodon have beneficial effects on the skin, these parts of the plant being rich in active ingredients.

[0008] A first object of the invention therefore corresponds to a cosmetic composition comprising as sole active ingredient an extract of the aerial parts of a plant of the genus Isodon for its use in reducing skin roughness, preventing wrinkles, reshaping the contour of the face, and increasing the density of the dermis.

[0009] Such a composition comprises a single active ingredient, which makes it possible to reduce its list of ingredients. This active ingredient is also of natural origin, this composition is therefore not aggressive for the skin, unlike compositions involving synthetic ingredients. This natural origin also advantageously has a positive impact on the environment.

[0010] According to one embodiment, the extract of only the aerial parts of the plant of the genus Isodon according to the invention is an aqueous extract.

[0011] The invention therefore uses, to obtain this extract, an extraction based on natural compounds, since the solvent for such an aqueous extraction is water. This aspect therefore has a positive impact on the environment. An aqueous extract also makes it possible to be less aggressive for the skin during application. It is also easy to introduce into cosmetic formulations, and not dangerous to handle.

[0012] According to one embodiment, this extract is present in a mixture consisting, in percentage by weight relative to the total weight of the mixture, of 40% glycerin, 10% pentylene glycol, 0.01% to 2% of the extract and water.

[0013] The extract according to the invention is thus stabilized and suitable for being formulated in cosmetic compositions intended to be applied to the skin. The use of glycerin and pentylene glycol advantageously makes it possible to limit the risks of microbial contamination, without having to integrate chemical preservatives as such into the compositions, which can be aggressive and irritating to the skin, particularly fragile skin.

[0014] According to one embodiment, the extract according to the invention is present in the mixture introduced previously at a rate of 0.05% to 1%, more preferably 0.1% to 0.6%, even more preferably 0.35% to 0.45% by weight, relative to the total weight of the mixture.

[0015] According to one embodiment, this mixture is present in the composition in an amount of 0.01% to 10%, preferably 0.5% to 5%, more preferably 0.8% to 3%, even more preferably 1% to 2% by weight, relative to the total weight of the composition.

[0016] According to another embodiment, the aerial parts of the plant of the genus Isodon of the extract correspond to its stem, and / or its leaves, and / or its flowers.

[0017] Such plant parts are rich in active ingredients, and easy to obtain / harvest, without damaging them. It is also easy to transform them for use in cosmetic formulations.

[0018] According to one embodiment, the composition according to the invention is intended to be applied topically to healthy skin.

[0019] According to another embodiment, the plant of the genus Isodon is the species Isodon japonicus.

[0020] A second subject of the invention relates to a process for preparing a composition as defined above, comprising an extract of only the aerial parts of the plant of the genus Isodon, this process comprising the following steps: - harvesting the aerial parts of the plant, and drying indoors at a temperature between 15°C and 25°C, preferably between 20°C and 25°C; - aqueous extraction from a plant content of between 2% and 3%, preferably 2.5%, for a period of between 1h30 and 2h30, preferably for 2h, at a temperature of between 50°C and 70°C, preferably 60°C; - sterilizing filtration to obtain the extract; - dilution of the aqueous extract obtained with glycerin and pentylene glycol, in respective proportions of 40% and 10% by weight, relative to the total weight of a mixture consisting of glycerin, pentylene glycol, the extract and water.

[0021] Such a preparation process is not toxic, and does not have a negative impact on the environment: it involves a reduced number of synthetic compounds, and at the very least no synthetic active ingredient, and it does not involve a significant temperature increase step.

[0022] A third object of the invention is the use of a composition as defined above for reducing the roughness of the skin, preventing the appearance of wrinkles, reshaping the contour of the face, and increasing the density of the dermis. Detailed description of the invention

[0023] Extract based on the aerial parts of a plant of the genus Isodon

[0024] The invention uses cosmetic compositions which comprise an extract of only the aerial parts of a plant of the genus Isodon as the only active ingredient of the composition. The plants of the genus Isodon which are suitable for these compositions belong to the Lamiaceae family.

[0025] Thus, according to the invention, an extract of only the aerial parts of a plant of the genus Isodon makes it possible to reduce the roughness of the skin, prevent the appearance of wrinkles, reshape the contour of the face, and increase the density of the dermis. Preferably the species Isodon japonicus is used.

[0026] This plant Isodon japonicus is native to Shirakami, which is a region located in the mountains of northern Honshü in Japan, in the Akita Province. This remote and particularly preserved region is classified as a UNESCO World Heritage Site.

[0027] Isodon japonicus is grown organically. Its stems and leaves are harvested in October / November. In fact, only its aerial parts are used to extract the active ingredient to be incorporated into the compositions according to the invention. These parts correspond to the stem, the leaves and the flowers.

[0028] According to other embodiments, the active ingredient to be integrated into the compositions of the invention can be extracted from a species other than Isodon japonicus, for example from the species Isodon trichocarpus. Isodon shikokianus, Isodon umbrosus, or even Isodon effusus.

[0029] Such an extract according to the invention is derived from an aqueous extraction process, it is therefore itself an aqueous extract. It thus has the advantage, due to its active ingredient of natural plant origin and its aqueous base, of limiting the risks of irritation on the skin and of having a positive impact on the environment. It is also easily formulated in a final cosmetic composition, the application of which will be topical. Composition comprising such an extract

[0030] The extract described above is therefore intended to be formulated in a final composition according to the invention, intended to be applied to the skin. For this, this extract is integrated into a mixture consisting of glycerin, pentylene glycol, the extract according to the invention and water. Glycerin and pentylene glycol make it possible to stabilize the Isodon extract, and are present in such a mixture in respective contents of 40% and 10% by weight, relative to the total weight of the mixture.

[0031] The extract according to the invention is thus present in this mixture in a content of 0.05% to 1%, more preferably 0.1% to 0.6%, even more preferably 0.35% to 0.45% by weight, relative to the total weight of the mixture. And this mixture is present in the finished composition in a content of 0.01% to 10%, preferably 0.5% to 5%, more preferably 0.8% to 3%, even more preferably 1% to 2% by weight, relative to the total weight of this composition. As a result, the extract & Isodon as such is present in the finished composition, intended to be applied to the skin, in relatively low contents, advantageously making it possible to limit the risks of irritation, or even allergies, on the skin of users. These low concentrations also have the advantage of making such a composition economical.

[0032] This composition can be presented in all the galenic forms normally used for topical application to the skin. It can then take the form, for example, of an aqueous or oily solution, a lotion, a serum, an emulsion, a milk, a cream, a gel, an ointment, a butter, an oil-in-water emulsion, a water-in-oil emulsion, or even a triple emulsion.

[0033] These formulations and textures are simple to produce, and are compatible with application to the skin. They will be chosen according to the desired application and the skin type. For example, it is interesting to formulate a serum for an application specifically targeting the eye area, and a cream for application to the majority of facial skin.

[0034] Process for preparing a composition according to the invention

[0035] A composition according to the invention, comprising an extract of the aerial parts of a plant of the genus Isodon, is prepared as follows: - first of all, the aerial parts of the plant are harvested, which are then dried indoors at a temperature between 15°C and 25°C, preferably between 20°C and 25°C; - an aqueous extraction step is then carried out, from a plant content of between 2% and 3%, preferably 2.5%, for a period of between 1h30 and 2h30, preferably 2h, and at a temperature of between 50°C and 70°C, preferably 60°C; - a sterilizing filtration step follows, which allows the final aqueous extract to be obtained; - then, the aqueous extract thus obtained is diluted in a mixture consisting of glycerin, pentylene glycol, the extract and water. The respective proportions of glycerin and pentylene glycol in this mixture are 40% and 10%, relative to the total weight of the mixture.

[0036] At this stage of the process, a mixture is obtained comprising the aqueous extract of the genus Isodon according to the invention. The preparation of the finished composition, intended to be applied to the skin, comprises additional steps of adding compounds, well known to those skilled in the art, which will therefore not be described further.

[0037] This preparation process is thus easy to implement, according to methods well known to those skilled in the art in the field of cosmetic formulation. It is economical, because it does not require particularly complex or expensive equipment, nor does it involve synthetic active ingredients, which can be relatively expensive. It also does not implement steps requiring a very significant rise in temperature, which is advantageous from both an economic and environmental point of view. Use of a composition according to the invention

[0038] The compositions according to the invention as described above, and comprising an extract of the aerial parts of a plant of the genus Isodon, are intended to be applied to the skin.

[0039] The use of these compositions may be daily or twice daily. It may be less frequent, such as once a week, twice a week, three times a week, four times a week, five times a week or six times a week.

[0040] Thus, the frequency of use of such compositions may be adapted according to the environment in which the user operates, their age and their lifestyle.

[0041] The invention will now be illustrated by the following non-limiting examples. Brief description of the figures

[0042] [Fig-1]: [Fig.l] is an image representing the dermo-epidermal junction of users having applied a composition comprising 2% of a mixture comprising an extract of the aerial parts of the plant Isodon japonicus respectively at T0 day (start of the test) and at T28 days (end of the test);

[0043] [Fig.2]: [Fig.2] is an image representing the support fibers of the dermis of users having applied a composition comprising 2% of a mixture comprising an extract of the aerial parts of the plant Isodon japonicus respectively at T0 day and at T28 days. Examples

[0044] Example 1: Effects of a composition comprising a single active ingredient derived from the aerial parts of the plant Isodon japonicus on the metabolism of keratinocytes in the epidermis

[0045] This example demonstrates the effects of an extract of the aerial parts of Isodon japonicus according to the invention on skin roughness, wrinkles and facial contour, in particular by direct action on the keratinocytes of the epidermis.

[0046] Test conditions:

[0047] Two compositions comprising a mixture as described above consisting of glycerin, pentylene glycol, an extract of Isodon japonicus according to the invention and water, this mixture being present in these compositions in respective contents of 0.1% and 0.5%, relative to the total weight of the composition, were tested in vitro on human epidermal keratinocytes (NHEK, for "Normal Human Epidermal Keratinocytes" in English), isolated from fragments of normal (healthy) skin.

[0048] The effect of the compositions on the metabolism of keratinocytes was analyzed by the method of quantification of total proteins in the keratinocyte samples.

[0049] Results:

[0050] The results of this analysis are expressed by reference with a control sample, which corresponds to NHEK keratinocytes which have not been put in contact with a mixture comprising an extract & Isodon.

[0051] Thus, the composition comprising 0.1% of the mixture comprising the extract & Isodon japonicus improves keratinocyte metabolism by 41% compared to the control sample. The composition comprising 0.5% of the mixture comprising The Isodon japonicus extract improves keratinocyte metabolism by 44% compared to the control sample.

[0052] This stimulation is directly linked to the cohesion of the epidermis and the reconstruction of the dermo-epidermal junction. These results thus demonstrate that the compositions according to the invention advantageously make it possible to reduce the roughness of the skin and the appearance of wrinkles. The contour of the face can also be reshaped by the topical application of such compositions.

[0053] Example 2: Effects of a composition comprising a single active ingredient derived from the aerial parts of the plant Isodon japonicus on the regeneration of the dermo-epidermal junction and the re-densification of the dermis.

[0054] This example demonstrates the effects of an extract of the aerial parts of Isodon japonicus according to the invention on skin roughness, dermal density, skin aging and facial contour, in particular by action on the dermo-epidermal junction and on the dermis.

[0055] Test conditions:

[0056] Two compositions comprising the mixture comprising an extract of Isodon japonicus according to the invention, this mixture being present at respective contents of 1% and 2%, relative to the total weight of the composition, were tested in vivo on 60 volunteers, selected on the basis of the criterion corresponding to skin lacking density. These people had to apply the composition twice a day for a period of 28 days.

[0057] Three parameters were analyzed, which are: - the roughness of the skin surface, - the length and sinusoidal aspect of the dermo-epidermal junction, and - the density of the dermis. Example 2a: Skin roughness analysis

[0058] Results:

[0059] The results of the specific analysis of the effect of the compositions according to the invention on the roughness of the skin are expressed with respect to a placebo sample. This has the same formula as the compositions of the invention tested, only the mixture at 1% and 2% by weight comprising the extract & Isodon japonicus is replaced by an equivalent content of water.

[0060] Thus, the roughness of the skin surface of users who applied the composition comprising 2% of the mixture comprising the extract & Isodon japonicus according to the invention decreased by 3.6% after 28 days (T28), compared to the starting day of the test (T0).

[0061] This decrease is 5.9% compared to the effect of topical application of the placebo.

[0062] These results thus demonstrate that the compositions according to the invention advantageously make it possible to reduce the roughness of the skin, and therefore to smooth the skin texture, which is aesthetically advantageous and sought after by users.

[0063] Example 2b: analysis of the architecture of the dermo-epidermal junction

[0064] Results:

[0065] After 28 days, it is observed that the dermo-epidermal junction regains a sinusoidal architecture, which is characteristic of young skin and a good junction between the layers of the dermis and the epidermis of the skin. This also illustrates a good capacity for resistance and support of the skin tissues.

[0066] [Fig. 1] illustrates this result. It compares the appearance of the dermo-epidermal junction of the users' skin before the application of the 2% composition in a mixture comprising the Isodon japonicus extract according to the invention (image at T0), with this appearance after 28 days of the test (image at T28). This result is visualized by analysis of images from the ultrasound technique

[0067] It is clearly visible that after 28 days, the line of the dermo-epidermal junction, present between the upper thin layer of the epidermis and the lower thicker layer of the dermis, actually has a sinusoidal configuration, therefore less flat than at T0. It is therefore observable that at T28, the surface epidermis is smoother and more homogeneous than at T0.

[0068] Example 2c: Analysis of the regeneration of the dermo-epidermal junction (DEJ)

[0069] Results:

[0070] The results of the specific analysis of the effect of the compositions according to the invention on the regeneration of the dermo-epidermal junction are expressed with respect to the placebo sample.

[0071] The results of this analysis are presented in Table 1 below.

[0072] [Tables 1] Composition Increase in JDE length (%) compared to T0 Increase in JDE length (%) compared to placebo 1% of the mixture comprising the extract + 0.7 + 1.1 2% of the mixture comprising the extract + 0.9 + 1.4 Placebo -0.4 /

[0073] Effect of the topical application of compositions according to the invention at 1% and 2% of the mixture comprising an extract of Isodon japonicus at the end of T28 compared to T0 and compared to the topical application of a placebo, on the regeneration of the DEJ

[0074] Thus, the length of the dermo-epidermal junction of users having applied the composition comprising 1% of the mixture comprising the extract of Isodon japonicus according to the invention increased by 0.7% after 28 days (T28), compared to the starting day of the test (T0).

[0075] This increase in length increases to 0.9% for the application of the composition comprising 2% of the mixture.

[0076] Conversely, topical application of the placebo reduces the length of the dermo-epidermal junction by 0.4% after 28 days, compared to T0.

[0077] Also, this increase in the length of the dermo-epidermal junction for the 1% and 2% compositions of the mixture comprising the extract & Isodon japonicus, compared to the placebo, is respectively 1.1% and 1.4%.

[0078] This increase in the length of the dermo-epidermal junction is linked to the more sinusoidal architecture of the dermo-epidermal junction obtained by application of the compositions according to the invention, as demonstrated in example 2b above.

[0079] These results thus support the fact that the compositions according to the invention advantageously make it possible to regenerate the dermo-epidermal junction, making it possible to remodel the contour of the face and reduce the appearance of wrinkles.

[0080] Example 2d: analysis of the re-densification of the dermis

[0081] Results 1:

[0082] After 28 days, it is observed that the support fibers of the dermis, a layer of the skin deeper than the epidermis, are denser.

[0083] [Fig.2] illustrates this result. It compares the appearance of the support fibers of the dermis of the users' skin before the application of the 2% composition in a mixture comprising the extract of Isodon japonicus (image at T0), with this appearance after 28 days of the test (image at T28). This result is visualized by analysis of images from the ultrasound technique. It is clearly visible that after 28 days, these support fibers are denser, the lighter areas in the figure, corresponding to the fibers of the dermis, being more extensive at T28.

[0084] Results 2:

[0085] The results of a complementary analysis of the effect of the compositions according to the invention on the re-densification of the dermis are always expressed with regard to the placebo sample.

[0086] The results of this analysis are presented in Table 2 below.

[0087] [Tables2] Composition Increase in dermal densification (%) compared to T0 Increase in half-e densification (%) compared to placebo 1% of the mixture comprising the extract + 15 + 3.9 2% of the mixture comprising the extract + 25 + 14.4 Placebo + 11 /

[0088] Effect of the topical application of compositions according to the invention at 1% and 2% of the mixture comprising an extract of Isodon japonicus at the end of T28 compared to T0 and compared to the topical application of a placebo, on the densification of the dermis

[0089] Thus, the re-densification of the dermis of users who applied the composition comprising 1% of the mixture comprising the extract & Isodon japonicus according to the invention increased by 15% after 28 days (T28), compared to the starting day of the test (T0). This increase increases to 25% for the application of the composition comprising 2% of the mixture.

[0090] Topical application of the placebo, for its part, increases this re-densification of the dermis by only 11% after 28 days.

[0091] This increase in the re-densification of the dermis for the 1% and 2% mixture compositions comprising the Isodon japonicus extract, compared to the placebo, is respectively 3.9% and 14.4%.

[0092] These additional results thus corroborate results 1 presented above, and demonstrate that the compositions according to the invention advantageously make it possible to increase the density of the users' dermis.

[0093] It is thus demonstrated, by all of these results, that compositions according to the invention, that is to say comprising as the sole active ingredient an extract of only the aerial parts of a plant of the genus Isodon, for example the plant Isodon japonicus, make it possible to reduce the roughness of the skin, prevent the appearance of wrinkles, reshape the contour of the face, and increase the density of the dermis.

Claims

Claims

1. Cosmetic composition intended to be applied to the skin, comprising as sole active ingredient an extract of the aerial parts of a plant of the genus Isodon, said extract reducing the roughness of the skin, preventing the appearance of wrinkles, reshaping the contour of the face, and increasing the density of the dermis, said extract being present in said composition in a mixture consisting, in percentage by weight relative to the total weight of said mixture, of 40% glycerin, 10% pentylene glycol, 0.01% to 2% of said extract, and water.

2. A composition according to claim 1, wherein said extract of only the aerial parts of the plant of the genus Isodon is an aqueous extract.

3. A composition according to claim 1 or 2, wherein said extract is present in said mixture in an amount of 0.05% to 1% relative to the total weight of said mixture.

4. A composition according to any one of claims 1 to 3, wherein said mixture is present in said composition in an amount of 0.01% to 10% relative to the total weight of said composition.

5. Composition according to any one of claims 1 to 4, wherein said aerial parts of the plant of the genus Isodon of said extract correspond to its stem, and / or its leaves, and / or its flowers.

6. Composition according to any one of claims 1 to 5, intended to be applied topically to healthy skin.

7. Composition according to any one of claims 1 to 6, characterized in that the plant of the genus Isodon is the species Isodon japonicus.

8. A method of preparing a composition according to claims 1 to 7, comprising an extract of only the aerial parts of the plant of the genus Isodon, said method comprising the following steps: - harvesting said aerial parts of said plant, and drying indoors at a temperature between 15°C and 25°C; - aqueous extraction from a plant content between 2% and 3%, for a period between 1h30 and 2h30, at a temperature between 50°C and 70°C; - sterilizing filtration to obtain said extract;

9. - dilution of said aqueous extract obtained with glycerin and pentylene glycol, in respective proportions of 40% and 10% by weight, relative to the total weight of a mixture consisting of glycerin, pentylene glycol, said extract and water. Use of a composition according to claims 1 to 7 for reducing the roughness of the skin, preventing the appearance of wrinkles, reshaping the contour of the face, and increasing the density of the dermis.

Images