BE1028846A1 - Cosmetic composition based on Rhodiola Rosea cells - Google Patents

Abstract

At least partially aqueous cosmetic composition containing at least (a) dedifferentiated unground Rhodiola Rosea cells enriched at least in xylitol and having xylitol in their internal volume defined by their cell wall, and (b) a carrier for cosmetic application.

Description

| BE2020/0127 Cosmetic composition based on Rhodiola Rosea cells The subject of the present invention is a cosmetic composition based on Rhodiola Rosea cells and Xilytol, in particular for improving and/or regulating the microbiological balance of the skin flora of an area of the human skin area. Improving and controlling the cutaneous flora is an essential problem in cosmetics because it makes it possible to obtain a smoother and more youthful rendering of the skin.

As stipulated in WO2019/149754, paragraphs 0056 to 0058: "The skin is a complex barrier organ which hosts many microorganisms on its surface (bacteria, fungi, viruses). This microflora colonizing the stratum corneum constitutes the cutaneous microbiota. It is acquired at birth and evolves to reach a state of equilibrium in adulthood. Its composition and abundance are influenced by genetics and lifestyle. This guarantees the uniqueness of the microbiota between individuals which can thus be qualified microbiological fingerprint Microorganisms and their host live in perfect harmony A balanced microbiota is harmless and beneficial to its host Among the diversity of skin flora, four main groups of bacteria (or phyla) have been characterized: Actinobacteria, Firmicutes, Proteobacteria, Bacteroidetes with three predominant species: Corynebacteria, Propionibacteria and Staphylococci The microbiota participates in the development and maintaining the balance of its host. Microorganisms and the skin barrier act in synergy to protect the skin from external aggressions. The cutaneous flora plays a fundamental role since it gives the skin immunity and protection against potential pathogenic colonizers. The cutaneous microbiota is today considered as a real functional unit of the skin which contributes to its health and its beauty.

; BE2020/0127 However, this balance is constantly threatened by various factors, intrinsic and extrinsic, which can alter the composition of the microbiota and the barrier function of the skin.

This microbiota imbalance, or dysbiosis, disrupts microbe-microbe and microbe-host cooperation and can lead to skin disorders.

It is therefore essential to maintain the balance of the cutaneous ecosystem in order to display skin of exceptional quality." Many solutions have already been proposed / suggested to ensure a certain control of the cutaneous flora, and thus to control in a certain way man-made odors.

The use of Rhodiola extract in cosmetics has already been proposed.

For example, document JP2000/128729 describes a cosmetic composition that moisturizes and gives a "clear" effect to the skin comprises an extract of a plant of the Rhodiola family, of which the species Kiringen Keikeiten (Rhodiola algida/Aomi, Haibei, Kaisei), Karako Redkeiten (Rhodiola algida var.

Tangutica/ Aomi, Sichuan), Nishikawa Kokeiten (Rhodiola alsia/Sichuan), Koza Beni Kageten (RHODIOLA dumulosa/Sichuan, Gansu), Kageten (RHODIOLA euryphylla, Tibet), Nagachifukukeiten (RHODIOLA fastigitaa, Tibet), Chorinkokeiten (Rhodiola Gelida/Utenyama ), Kageten (RHODIOLA henryi/Gansu, Henan, Hubei, Sichuan, Guizhou), RHODIOLA heterodonta/Xinjiang, Tibet, Kageten (RHODIOLA Kirirowii/Hebei, Shanxi, Yunnan, Sichuan, Tibet), RHODIOLA quadrifida/Gansu, Aomi, Xinjiang, Sichuan, Tibet; , Sekijj Benkeiten (RHODIOLA sacra, Tibet), Zokukeiten (RHODIOLA scabrida/ Sichuan, Tibet), RHODIOLA wallichiana, Yunnan, Tibet, RHODIOLA wallichiana and Rhodiola cholaensis/Aoumi, Tibet, Sichuan, Yunnan.

There is no mention in this document of the use of Rhodiola plant cells enriched with Xylitol, in particular to control the skin microbiota.

Anti-wrinkle compositions comprising an extract of Rhodiola Rosea as an anti-wrinkle agent to be used in combination with others are for example taught in CN103784376, CN103690406, CN105456114, etc.

These documents show that the extracts of Rhodiola Rosea are not considered as such as sufficient to treat the problem of wrinkles.

Rhodiola Rosea extract is therefore only considered effective in combination with another extract for anti-wrinkle treatment.

Various extraction methods exist, for example using grinding steps, followed by extraction steps using one or more solvents.

A particular extraction process applicable to plants is described in document EP2575993, this process using a powerful eutectic solvent, a sugar or an alcohol chosen from a family comprising xylitol, an organic acid, and an inorganic compound. this extraction step amounts to bursting the plant cells to remove one or the other active ingredient.

The document CN106520665 describes the in vitro culture of Rhodolia-Rosea cells in culture media enriched with plant hormones.

This culture medium is then subjected to an extraction step using a solvent of the alcohol type.

The product thus obtained is also an alcoholic extract.

By document CN101444456, the cosmetic use of xylitol as a moisturizing agent is described, in combination with a fatty acid, an emulsifier and water.

The applicant has now noticed that the use of dedifferentiated cells of unground Rhodiala Rosea containing inside their envelope or cell wall Xylitol made it possible as such to have an effect to improve and

/or control the skin flora over a period of several days, while ensuring a moisturizing effect for the skin cells. This solution is neither described nor suggested in the solutions proposed in the state of the art. The subject of the invention is an at least partially aqueous cosmetic composition containing at least (a) dedifferentiated unground Rhodiola Rosea cells enriched at least in xylitol and having in their internal volume defined by their cell wall xylitol, and (b) a support for cosmetic application. This composition is for topical application. According to advantageous forms of the composition according to the invention, the composition has one or more of the following characteristics: - the composition contains at least (a) dedifferentiated and elicited cells of unground Rhodiola Rosea enriched at least in xylitol in their internal volume defined by their cell wall, (b) xylitol outside the internal volume of the cells, (c) glycerin and (d) a carrier for cosmetic application.

- the composition also contains (e) a ground material of dedifferentiated and elicited cells of Rhodiola Rosea. - the weight ratio between the unground, dedifferentiated and elicited cells of Rhodiola Rosea enriched at least in xylitol in their internal volume, and the ground material of dedifferentiated and elicited cells of Rhodiola Rosea is between 1:10 and 10:1. - the dedifferentiated and elicited cells of unground Rhodiola Rosea enriched at least in xylitol in their internal volume defined by their cell wall present on their cell wall at least one or more zones comprising xylitol and glycerin. - the dedifferentiated and elicited cells of unground Rhodiola Rosea enriched at least in xylitol in their internal volume defined by their cell wall comprise at least phytoalexins and xylitol, the ratio by weight xylitol! / phytoalexins in the internal volume of the cells defined by their cell wall being greater than 0.3, advantageously greater than 0.5, preferably greater than

1.

- the dedifferentiated, and advantageously elicited, cells of unground Rhodiola Rosea enriched at least in Xylitol and having in their internal volume defined by their cell wall Xylitol are cells prepared by separating from their culture medium, a callus comprising dedifferentiated cells , and advantageously elicited, and by mixing this Rhodiola Rosea cell callus with xylitol or an aqueous liquid composition containing xylitol, the aqueous callus/Xylitol weight ratio being greater than 1:1 (advantageously greater than 2:1, of preferably between 5:1 and 10:1) and being adapted to the water content of the callus to avoid any crystallization of the xylitol mixed with the callus at a temperature between 15 and 40°C. - the callus is mixed with powdered xylitol, with an aqueous callus/xylitol weight ratio adapted to ensure the total dissolution of the xylitol at a temperature of between 15 and 40° C. in the water contained in the callus.

- the callus, after mixing its mixture with xylitol, is mixed with glycerol, the glycerol/xylitol weight ratio being greater than 0.5:1, advantageously greater than 1:1, preferably greater than 10:1; in particular between 10:1 and 50:1.

- the callus after mixing with xylitol and glycerol is subjected to partial crushing, so that at least 50% by weight of the dedifferentiated cells of Rhodiola Rosea have a cell wall in an uncrushed state.

- the callus of dedifferentiated and advantageously elicitated cells, optionally subjected to grinding, advantageously mixed with glycerol, is subjected to elicitation at atmospheric pressure, at a temperature of 20 to 40° C., and in air with a rate relative humidity of more than 50%, advantageously more than 75% enriched in CO2 so that its CO2 content is between 3 and 10% by volume, comprising at least two illumination stages in the length range of waves between 400 and 720 nm each with a duration of 20 to 120 minutes with an intensity of more than 1000 lux, advantageously more than 10,000 lux and separated from each other by a period of darkness of less than 100 lux lasting between 20 and 60 minutes.

- the callus of dedifferentiated and elicited cells of Rhodiola Rosea, after drying at - 40°C and under a pressure of 100 Pa or less than 100 Pa, to obtain a dried callus having a moisture content of less than 0.5% by weight , contains more than 0.5% by weight of mixture of tyrosol and Salidroside based on the weight of the callus after drying. Advantageously, the dried callus contains more than 0.5% by weight of salidroside, preferably from 0.6% to 1.2% by weight, and more than 0.1% by weight of tyrosol, preferably from 0.2 % to 0.6% by weight, based on the weight of the callus after drying or dried callus.

- the composition contains a remainder of culture medium comprising vitamins, advantageously a B vitamin, in particular vitamin B7 and/or vitamin B1 and/or vitamin B3 and/or vitamin B4 and/or vitamin B6 and/or a mixture of such vitamins.

- the composition contains from 0.1 to 10% by weight of dedifferentiated cells of unground Rhodiola Rosea enriched at least in xylitol and having in their internal volume defined by their cell wall xylitol.

- the dedifferentiated cells of Rhodiola Rosea, before mixing with xylitol, are subjected to an elicitation cycle in their growth medium, said elicitation cycle comprises, and advantageously elicited, optionally subjected to grinding, advantageously mixed with glycerol is subjected to elicitation at atmospheric pressure, at a temperature of 20 to 40° C., and in air with a relative humidity rate of more than 50%, advantageously 75% or more than 75% enriched in CO2 so that its CO2 content is between 3 and 10% by volume, comprising at least two illumination stages in the wavelength range between 400 and 720nm each with a duration of 20 to 120 minutes with an intensity of more than 1000 lux, advantageously of more than 10,000 lux and separated from each other by a period of darkness of less than 100 lux lasting between 20 and 60 minutes - the composition is suitable for ensuring an improvement in the microbiological balance of e the cutaneous flora, while advantageously providing an anti-aging or anti-aging action and/or a protective action against UV rays and/or an antioxidant and/or antibacterial activity.

- a combination of such characteristics.

A further subject of the invention is a cosmetic, non-therapeutic treatment of an area of the skin of a human being in order to improve and/or regulate the microbiological balance of the cutaneous flora of this area, in which one applies to said zone a cosmetic composition according to the invention as described above. This cosmetic treatment also advantageously provides an anti-aging or anti-aging cosmetic treatment and/or a protective cosmetic action against UV rays and/or an antioxidant cosmetic activity and/or an antibacterial cosmetic activity.

Dedifferentiated plant cells of Rhodiola Rosea can be obtained from plant material derived from whole plant or plant part such as leaves, stems, flowers, petals, roots, fruits, their skin, the envelope the protecting, seeds, anthers, sap, thorns, buds, bark, berries, and mixtures thereof. The dedifferentiated plant cells, however, preferably come from roots of Rhodiola Rosea, in particular from rootlets of Rhodiola Rosea.

The dedifferentiated plant cells that can be used according to the invention can be obtained from plants obtained by in vivo culture or derived from in vitro culture.

By in vivo culture is meant any culture of the conventional type, that is to say in soil in the open air or in a greenhouse or else above ground or in a hydroponic medium.

By in vitro culture is meant all the techniques known to those skilled in the art which artificially make it possible to obtain a plant or part of a plant. The selection pressure imposed by the physico-chemical conditions during the growth of plant cells in vitro makes it possible to obtain standardized plant material, free of contamination and available throughout the year, unlike plants cultivated in vivo.

Preferably, according to the invention, dedifferentiated plant cells obtained from in vitro culture are used. The elicitation of the cells is preferably carried out with the cells in a culture medium.

The dedifferentiated plant cells which can be used according to the invention can be obtained by any method known from the prior art. In this respect, we can cite the methods described by E.F. George and P.D. Sherrington in Plant Propagation by tissue culture, handbook and directory of commercial laboratories (Exegetics Ltd 1984).

The culture media which can be used according to the invention are those generally known to those skilled in the art. We can cite as examples the media of Gamborg, Murashige and Skoog, Heller, White etc. Full descriptions of these media can be found in "Plant Culture Media: formulations and uses" by E.F. George, DJM Puttock and H.J George (Exegetics Ltd 1987, volumes 1 & 2). on Gamborg's medium Particularities and details of compositions according to the invention will become apparent from the following description of exemplary embodiments given by way of example only.

Tests demonstrating the effectiveness of cosmetic compositions according to the invention will be described below. In these examples, elicited Rhodiola Rosea cells were used.

These cells were prepared as follows: Step 1: Preparation of dedifferentiated cells of Rhodiola Rosea and cultured in an in vitro culture medium of the Gamborg type.

Rhodiola Rosea rootlet cells (rootlets with a diameter of less than 2 mm) were taken. This stage of preparation of dedifferentiated cells of Rhodiola Rosea was carried out in a conventional manner, with successive stages of transplanting, from rootlets.

The culture medium used is a complete Gamborg BS medium (G5893) marketed by Sigma-Aldrich (Germany). Other culture media are possible.

Stage 2: subculturing of the dedifferentiated cells from stage 1 in an in vitro culture medium for the development and elicitation of the cells.

The growth with elicitation of the cells of stage 1 was carried out in an in vitro medium (Gamborg B5) under a gaseous atmosphere containing oxygen and CO: (air enriched in CO, so that its CO2 content is 8% by volume) according to a cycle comprising 100 periods of low luminosity with a luminosity of less than 10 lux (from 1 to 5 lux) for 30 minutes in an atmosphere consisting of humid air (relative humidity of 85%) enriched with CO , (so that the CO content is 8% by volume) and having a temperature of 30° C., these periods of development/elicitation under low (or even without) light being separated from each other by a period luminosity of more than 100,000 lux (wavelength range between 400 and 720 nm) for 1 hour in an atmosphere consisting of humid air (relative humidity of 85%) enriched with CO (so that the CO content, the atmosphere is 8% by volume) and having a temperature of 35°C.

The transition from a dark state to an illuminated state and vice versa is achieved by moving an opaque wall.

This in vitro culture under elicitation is carried out in a white room.

Stage 3: Extraction of the callus from the dedifferentiated and elicited cells in in vitro culture medium, by filtration of the culture medium followed by several stages of washing with water, carried out so as not to destroy the structure of the cell membranes.

The washed callus was drained for 45 minutes.

This cal (named CAL 1) will be used in part for the preparation of a comparative composition.

Part of this callus was subjected to drying by freeze-drying at −40° C. for determination of the saliroside and tyrosol content of the callus after drying by UPLC chromatography (high performance liquid chromatography). The drying operation is carried out by freeze-drying under vacuum (100 Pa and less if necessary, temperature of -40° C.), to obtain a powdery product with a water content of less than 1.5% by weight.

If the texture of the dried product is not optimal, it can be subjected to grinding.

For this chromatography, 0.3 g of powder is dissolved in 25 ml of a solvent consisting of 90% by weight water and 10% by weight acetonitrile.

After dissolution, the solution is filtered through a 0.45 µm filter.

UPLC chromatography of the Rhodiola extract was analyzed using an ACQUITY UPLC chromatography system marketed by Waters Corporation, 34 Maple Street, Milford, MA 01757, USA.

The chromatograph included a BEH C18 column, 100 mm in length, 2.1 mm inside diameter, spherical packing particles 1.8 µm in diameter.

The volume of analyte injected into the column was 2 µl. a solvent consisting of water and acetonitrile is then introduced into the column at a flow rate of 0.6 ml/minute at 75° C., for 14 minutes, while gradually increasing the concentration of acetonitrile (concentration varying gradually from 2.5% by weight to 100% by weight over 14 minutes). Tyrosol and salidroside are detected by UV at 221 nm at 30 seconds and 90 seconds.

Based on this chromatography, it was possible to calculate a content of 0.8% by weight of salidroside and 0.3% by weight of tyrosol, relative to the dry weight of the callus.

Step 4: Mixing with the drained callus of dedifferentiated and elicited cells of Rhodiola Rosea with a quantity of xylitol.

The quantity of xylitol added (powdered) is such that the ratio by weight Xylitol/weight of the drained callus (still moist) is 1:8. The mixture is carried out gently with a spatula until the xylitol has completely dissolved.

Stage 5: subculturing and elicitation the callus from stage 4 is subcultured into a Gamborg B5 culture medium to be subjected to elicitation. This elicitation was carried out in an in vitro medium (Gamborg B5) under a gaseous atmosphere containing oxygen and CO, (air enriched in CO, so that its CO2 content is 8% by volume) comprising a cycle consisting two steps of elicitation by radiation in the range 400-720 nm under an atmosphere consisting of humid air (relative humidity of 85%) enriched with CO, (so that the CO content is 8% by volume) and having a temperature of 30°C, each elicitation step having a duration of 90 minutes with a luminosity of 10000lux, said two elicitation steps being separated from each other by a resting step with a luminosity of 100lux ( wave range between 400 and 720 nm) for 45 minutes in an atmosphere made up of humid air (relative humidity of 85%) enriched in CO (so that the CO content of the atmosphere is 8% by volume) and exhibiting a temperature of 35°C, the transition from a dark state to an illuminated state and vice versa is carried out by the displacement of an opaque wall. This in vitro culture under elicitation is carried out in a white room.

Step 6: Extraction of callus from dedifferentiated and elicited cells in the presence of Xylitol in in vitro culture medium, by filtration of the culture medium followed by several washing steps with water, performed so as not to destroy the structure of the cell membranes elicited in the presence of xylitol. The washed callus was drained for 45 minutes.

Stage 7: addition of glycerol and mixing of the callus with the glycerol A quantity of glycerol is added to the callus in the proportion of a quantity corresponding to 15 times the quantity of xylitol added in stage 4. Step 8: partial crushing of the callus with xylitol and glycerol. The grinding is partial to obtain a mixture of ground cells and unground cells. This partial grinding can for example be carried out by dividing the callus into two parts, a first part representing 20% by weight of the callus being subjected to grinding, while the second part representing 80% by weight of the callus is not subjected to grinding. .

The two parts are then gently mixed together to form a mixture of uncrushed cells and crushed cells, containing Xylitol and glycerin. This mixture is referred to below as "Rhodiola X-G" in the embodiment examples.

Step 9: addition of a carrier for cosmetic application to obtain a cosmetic composition for topical application.

The cosmetic composition comprises, for example, from 0.5 to 15% by weight of a mixture of plant cells, ground and unground, of xylitol and of glycerin.

A few non-limiting examples of such cosmetic compositions for topical use will be given below Fxample 1: Dispersion of Rhodiola X-G in a cosmetic base — Rhodiola X-G is dispersed in the following base: - Deionized water 85.0%

- Mineral oil 9.00% - Cetyl alcohol 3.00% - ceteareth — 20 0.75% - Rhodiola X-G 2.00% 5- fragrance 0.15% - carbomer 0.10% TOTAL 100.00% The composition obtained shows a homogeneous dispersion of the cells in the cream and a very fine texture. The property study showed the absence of germs and fungi as well as a remarkable stability of the composition.

Example 2: Dispersion of Rhodiola X-G in another cosmetic base The Rhodiola X-G is dispersed in the following base: - water 46.59% - sodium laureth sulphate (25%) 36.40% - PEG-7 glyceryl cocoate 2.00 % 20- laureth-2 1.50% - sodium laureth-11 carboxylate 4.00% - cocamidopropyl betaine & benzoic acid 3.48% - sodium chloride 1.60% - perfume 0.13% 25- PEG-40 hydrogenated castor oil & propylene glycol & water 0.50% - oleth-10 0.50% - sodium phosphate 0.30% - disodium phosphate 0.08% 30- citric acid (50%) 0.52% - benzoate sodium 0.50%

- Rhodiola X-G 0.90% TOTAL 100.00% The composition obtained shows a homogeneous dispersion of the cells.

The property study showed the absence of germs and fungi as well as a remarkable stability of the composition.

Example 3: Lotions Lotions containing only Rhodiola X-G: demineralized water, propylene glycol, preservative, perfume; and active product: Rhodiola X-G.

Example 5: Shampoos Shampoos/gels/milks containing only an aqueous phase A based on demineralised water, detergents, foamers, thickeners, fragrance and active product: Rhodiola X-G, in the form of a viscous suspension or a gel.

Regarding lotions, solutions and shampoos, the composition for topical use contains the various constituents, the contents of which can be varied depending on the applications, mixed in the aqueous phase alone, as is usually realized by those skilled in the art in this field. .

The proportion of Rhodiola X-G depends on the nature of the composition for topical use and the desired application.

It is advantageously between 0.01 and 5%, but can reach up to 25%. Obviously, the invention is not limited to the embodiments given above and it is possible to produce the composition for topical use in other forms, such as oil, ointment, lacquers, make-up (foundation, powder , lipstick, pencil, mascara or cosmetic product making it possible to highlight the eyes by coloring the eyelashes and/or giving them more length or apparent thickness, eye shadow) which also come within the scope of the invention. Efficacy tests The microbial flora of human skin is very complex, including aerobic and anaerobic germs, gram positive and gram negative germs, yeasts. The cutaneous flora includes on the one hand the natural, resident and non-pathogenic flora, and on the other hand, an exogenous flora which develops during a weakening of the natural defenses, a wound, an infection, etc.

The resident or natural skin flora is composed of several species, including: Staphylococci (S.epidermis, S.hominis, S.haemolyticus, S.aureus), Corynebacteria (C.lipophiles; C.urealyticum; C.minutissimum; C.jeikeium ), Propionibacterium (P. acnes; P.avidum; P. granulosum, P.propionicum), Micrococci (M.luteus; M.varians), Streptococci (groups A, B and G), Brevibacteria.

It is generally accepted that the resident, natural flora has a protective role insofar as it "occupies the ground", where it sometimes secretes antimicrobial substances (antibiotics) which defend the skin against other species and where it maintains the defensive system of the skin (immune system) on the alert. Skin disorders are linked to the disruption of the ecological balance of the resident flora following the colonization of the skin by exogenous germs or the abnormal proliferation of an endogenous strain, this abnormal profiling may be the consequence of use too frequent bactericidal, antimicrobial, anti-virucidal, anti-fungal, antibiotic compositions, etc. non-selective, attacking the pathogenic flora and the resident flora indiscriminately. Such use of non-selective compositions is a source of development of resistant exogenous strains. The proliferation of exogenous strains results in various phenomena, including: the development of body odors, in particular axillary and foot odors (mainly C. xerosis for axillary odors and B. linens for foot odors); for people with sensitive skin, atopic dermatitis, eczema (responsible germ: S.aureus); dandruff production (mainly M. furfur); for people with oily or hyperseborrheic skin, acne (P. acnes); etc The use of non-specific antibiotics or bactericides poses the problem of the risk of the appearance of bacterial resistance, and problems of skin tolerance (irritations, allergies, etc.).

In particular in this period of Coronavirus, the repeated washing and disinfection of the hands with hydroalcoholic solutions have resulted in disturbances of the natural cutaneous flora, thus favoring the appearance and development of exogenous microbial species, even pathogens to the detriment natural flora. This appearance and rapid development of exogenous and pathogenic microbial species are a major source of contamination between people, and of the spread of diseases.

The cosmetic composition according to the invention has shown, during tests on volunteers, that it allows maintenance of a beneficial microbial balance on the skin, even and especially after repeated aggressions of the hydroalcoholic type. For efficacy testing, face lotion was used. The pH of this lotion is 7.5.

This face lotion was used to prepare the following test lotions: Reference lotion: "LR" base lotion

Comparative lotion 1: base lotion added with Xylitol to obtain a Xylitol content of 1% by weight. "LCOMP1" Comparative lotion 2: base lotion added with CAL 1 to obtain a CAL 1 content in the lotion of 8% by weight. "LCOMP2" Comparative lotion 3: base lotion added with CAL 1 to obtain a content of CAL 1 in the lotion of 8% by weight, and added with glycerin to obtain a content of 15% by weight. "LCOMP3" Lotion according to the invention: base lotion added with "Rhodiola X-G" in sufficient quantity to obtain a lotion with a content of 1% by weight of Xylitol.

Twelve volunteers took part in the test by following the protocol below: The face is washed with a liquid soap of pH 7.5, then rinsed and dried.

Skin pH is determined using a specific surface electrode. A sample of the microbial flora from the face is taken using agar plates for each volunteer.

The volunteers were divided into four groups, the reference group which will be treated with the LR lotion, the comparative group 1 which will be treated with the LCOMP1 lotion, the comparative group 2 which will be treated with the LCOMP2 lotion, and the invention group which will be treated with Rhodiola X-G lotion. After this treatment with a lotion, the treated areas were brought into contact (1 hour after the treatment) with exogenous Corynebacterium xerosis strains to determine their proliferation. These exogenous strains after the test were killed by an antibiotic cream. The treated area is limited to 4cm?, so as to be able to observe any differences with the untreated area for the same volunteer. Measurements of the pH of the skin before treatment, and then of the treated zone, are carried out at various times after treatment, namely 2 hours, 4 hours, 8 hours and 16 hours after treatment. Similarly, samples of microbes are taken from the treated areas at various times, namely 2, 4, 8 and 16 hours after treatment. 16 hours after treatment, washing is carried out with liquid soap of pH 7.5.

The time required for the treated zone to regain its initial pH before treatment is then determined. 1, 2 and 4 hours after washing, the skin flora of the washed treated area is examined.

In the event of excessive development of Corynebacterium xerosis on the treated area, the test is stopped and the area is treated quickly with a topical antibiotic cream. ; Before treatment, but after washing and drying, the skin of the volunteers had a pH of 4.9 to 5.3. The cutaneous microbial flora consisted essentially of the following species: Staphylococci (S.epidermis, S.hominis, S.haemolyticus, S.aureus), Corynebacteria (C.lipophiles; C.urealyticum; C.minutissimum; C.jeikeium), Propionibacteria (P. acnes; P.avidum; P. granulosum, P.propionicum), Micrococci (M.luteus; M.varians), Streptococci (groups A, B and G), Brevibacteria.

The cutaneous bacterial flora for the areas that will be subjected to treatment did not include Corynebacterium xerosis.

For the volunteers treated with the LR reference lotion, the pH of the treated area increases rapidly by one to two units, moreover a proliferation of the Corynebacterium xerosis strain is visible 4 hours after the start of the treatment. The resident skin microbial flora was disturbed. The test was interrupted and the treated area was subjected to a washing, rinsing and drying step. 3 hours after this washing step, the pH of the treated area returned to a value of 5.2-5.5.

To prevent any future proliferation of Corynebacterium xerosis, the treated area washed and rinsed was treated with antibiotic cream.

For the volunteers treated with the comparative lotion LCOMP1, the pH of the treated area increases rapidly by one to two units, moreover a proliferation of the Corynebacterium xerosis strain is visible 8 hours after the start of the treatment. The resident skin microbial flora was disturbed. The test was interrupted after 8 hours and the treated area was subjected to a washing, rinsing and drying step. 2 hours after this washing step, the pH of the treated area returned to a value of 5.2-5.5.

To prevent any future proliferation of Corynebacterium xerosis, the IS-treated and washed area was treated with antibiotic cream.

For the volunteers treated with the reference lotion LCOMP2, the pH of the treated area increases rapidly by one to two units, moreover a proliferation of the Corynebacterium xerosis strain is visible 8 hours after the start of the treatment. The resident skin microbial flora was disturbed. The test was interrupted and the treated area was subjected to a washing, rinsing and drying step. 2 hours after this washing step, the pH of the treated area returned to a value of 5.2-5.5.

To prevent any future proliferation of Corynebacterium xerosis, the treated and washed area was treated with antibiotic cream.

For the volunteers treated with the lotion of the invention Rhodiola X-G, the pH of the treated area increases by one unit. After 16 hours, no proliferation of the Corynebacterium xerosis strain was observed. The resident microbial cutaneous flora remained close to the original flora. The test was interrupted after 16 hours and the treated area was subjected to a washing, rinsing and drying step.

1 hour after this washing step, the pH of the treated and washed area returned to a value of 5.2-5.5. The lotion according to the invention therefore effectively protects the resident skin flora, while having a protective action against exogenous microorganisms.

The skin treated with the lotion of the invention had a more supple, softer, more hydrated appearance than the untreated skin, and the treatment did not cause redness and irritation.

Efficacy test on the growth of Corynebacterium xerosis, Staphylococcus epidermidis and Propionibacterium acnes germs The inhibitory or non-inhibiting action of the lotions was evaluated on the growth of Corynebacterium germs. xerosis (main germ responsible for bad body odor), Staphylococcus epidermidis (beneficial bacteria in the microbial flora of the skin), and on the Propionibacterium acnes germ (germs present on hyperseborrheic skin - responsible for acne breakouts). The germs were each placed in an agar culture medium. Wells were operated for each culture dish, each well being intended to receive the same quantity of lotion (LR or LCOMP1 or LCOMP2 or Rhodiola X-G. No inhibitory action or a weak inhibitory action was observed on Corynebacterium xerosis, Staphylococcus epidermidis, and on the Propionibacterium acnes germ, for the LR lotion For the LCOMP1 lotion, no inhibitory effect for Corynebacterium xerosis, but a certain inhibition for Staphylococcus epidermidis, and for the Propionibacterium acnesC germ

For the LCOMP2 lotion, no inhibitory effect for Corynebacterium xerosis and Staphylococcus epidermidis, but a certain inhibition for the Propionibacterium acnes germ (acne). For the Rhodiola X-G lotion, a marked inhibitory effect is observed for Corynebacterium xerosis and Propionibacterium acnes, and no inhibitory effect for Staphylococcus epidermidis.

This makes it possible to preserve the resident cutaneous flora, while having an action on Corynebacterium xerosis, and Propionibacterium acnes.

Claims (15)

Claims 1. At least partially aqueous cosmetic composition containing at least (a) dedifferentiated unground Rhodiola Rosea cells enriched at least in xylitol and having xylitol in their internal volume defined by their cell wall, and (b) a carrier for cosmetic application . 2. Composition according to claim 1, characterized in that it contains at least (a) dedifferentiated and elicited cells of unground Rhodiola Rosea enriched at least in xylitol in their internal volume defined by their cell wall, (b) xylitol outside the internal volume of the cells, (c) glycerin and (d) a carrier for cosmetic application. 3. Composition according to claim 1 or 2, characterized in that it additionally contains (e) a homogenate of dedifferentiated and elicited cells of Rhodiola Rosea. 4. Composition according to claim 3, characterized in that the weight ratio between the unground, dedifferentiated and elicited cells of Rhodiola Rosea enriched at least in xylitol in their internal volume, and the ground material of dedifferentiated and elicited cells of Rhodiola Rosea is between 1:10 and 10:1. 5. Composition according to any one of the preceding claims, characterized in that the dedifferentiated and elicited cells of unground Rhodiola Rosea enriched at least in xylitol in their internal volume defined by their cell wall present on their cell wall at least one or more areas comprising xylitol and glycerin. 6. Composition according to any one of the preceding claims, characterized in that the dedifferentiated and elicited cells of unground Rhodiola Rosea enriched at least in xylitol in their internal volume defined by their cell wall comprise at least phytoalexins and xylitol, xylitol/phytoalexins weight ratio in the internal volume of the cells defined by their cell wall being greater than 0.3, advantageously greater than 0.5, preferably greater than 1. 7. Composition according to any one of the preceding claims, characterized in that the dedifferentiated and advantageously elicited cells of unground Rhodiola Rosea enriched at least in Xylitol and having in their internal volume defined by their cell wall Xylitol are cells prepared in separating from their culture medium, a callus comprising dedifferentiated cells, and advantageously elicited, and by mixing this callus of Rhodiola Rosea cells with xylitol or an aqueous liquid composition containing xylitol, the aqueous callus/Xylitol weight ratio being higher at 1:1 and being adapted to the water content of the callus to avoid any crystallization of the xylitol mixed with the callus at a temperature between 15 and 40°C. 8. Composition according to claim 7, characterized in that the callus is mixed with powdered xylitol, with an aqueous callus/xylitol weight ratio adapted to ensure the total dissolution of the xylitol at a temperature between 15 and 40°C in the water contained in the callus. 9. Composition according to claim 7 or 8, characterized in that the callus, after mixing its mixture with xylitol, is mixed with glycerol, the glycerol/xylitol weight ratio being greater than 0.5: 1, advantageously greater than 1 : 1, preferably greater than 10:1; in particular between 10:1 and 50:1. 10. Composition according to claim 9, characterized in that the callus after mixing with xylitol and glycerol is subjected to partial grinding, so that at least 50% by weight of the dedifferentiated cells of Rhodiola Rosea have a wall cell in an uncrushed state. 11. Composition according to any one of claims 7 to 10, characterized in that the callus of dedifferentiated cells, and advantageously elicited, optionally subjected to grinding, advantageously mixed with glycerol is subjected to elicitation at atmospheric pressure, at a temperature of 20 to 40°C, and in air with a relative humidity rate of more than 50%, advantageously 75% or more than 75% enriched in CO2 so that its CO2 content is between 3 and 10% by volume, comprising at least two illumination steps in the wavelength range between 400 and 720 nm each with a duration of 20 to 120 minutes with an intensity of more than 1000 lux, advantageously more than 10000 lux and separated from each other by a period of darkness of less than 100lux lasting between 20 and 60 minutes. 12. Composition according to any one of claims 7 to 11, characterized in that the callus of dedifferentiated and elicited cells of Rhodiola Rosea, after drying at -40° C. and under a pressure of 100 Pa or less than 100 Pa, for obtain a dried callus having a moisture content of less than 0.5% by weight, contains more than 0.5% by weight of mixture of tyrosol and Salidroside based on the weight of the callus after drying. Advantageously, the dried callus contains more than 0.5% by weight of salidroside, preferably from 0.6% to 1.2% by weight, and more than 0.1% by weight of tyrosol, preferably from 0.2 % to 0.6% by weight, based on the weight of the dried callus or callus after drying. 13. Composition according to any one of the preceding claims, characterized in that it contains from 0.1 to 10% by weight of dedifferentiated cells of unground Rhodiola Rosea enriched at least in xylitol and having in their internal volume defined by their xylitol cell wall. 14. Composition according to claim 13 for improving the microbiological balance of the skin flora. 15. Cosmetic, non-therapeutic treatment of an area of the skin of a human being to improve and/or regulate the microbiological balance of the skin flora of this area, in which a cosmetic composition according to the one of claims 1 to 14.