Cosmetic use of a composition comprising a Pickering oil-in-water emulsion containing an organomodified phyllosilicate as a neurocosmetic agent

Abstract

Cosmetic, non-therapeutic, topical use of a composition as a neurocosmetic agent, said composition comprising a Pickering H / E emulsion containing an aqueous phase, a vegetable oil phase and an organomodified phyllosilicate. Figure to be published with the abstract: none.

Description

Title of the invention: Cosmetic use of a composition comprising a Pickering oil-in-water emulsion containing an organomodified phyllosilicate as a neurocosmetic agent

[0001] The present invention relates to the field of neurocosmetics and more particularly to the use of a composition comprising a particular Pickering oil / water emulsion as a neurocosmetic agent.

[0002] The skin is the main protective barrier of the human body against external aggressions such as air pollution, climatic variations and UV radiation.

[0003] The skin consists of three layers: the epidermis, the dermis, and the hypodermis. The epidermis, which is in contact with the superficial layer, is particularly involved in interactions with the external environment. The epidermis is covered by a hydrolipidic film and is composed of four layers: the stratum corneum, the stratum granulosum, the stratum spinosum, and the stratum basale. The epidermis is normally composed of four types of cells: keratinocytes, which represent 80% of all its cells, with the remaining 20% ​​being composed of melanocytes, Langerhans cells (or immunocompetent cells), and Merkel cells, these three cell groups being dispersed among the keratinocytes.

[0004] More specifically, Merkel discs are superficial receptors located at the base of the epidermis and composed of the terminal of a disc-shaped branch of a myelinated fiber attached to a Merkel cell with which it establishes synaptic contacts. Areas rich in Merkel discs can form tactile domes that respond to localized pressure, the stimulus response being phasicotonic with slow adaptation.

[0005] Recently, research on Merkel cells has focused on their function in mechanosensation, in particular light touch, because of their primary role in sensory tasks and social interactions.

[0006] In particular, it has been shown that Merkel cells use serotonin to transmit tactile stimuli to the terminals of the AP-afferent nerves with which they are in contact and that tactile stimuli activate Piezo 2 channels to transduce mechanical stimuli into electrical stimuli leading to the generation of impulses on the AP-afferent nerves (1).

[0007] This research has highlighted the importance of serotonin in the neurotransmission of information from skin cells in the epidermis.

[0008] Neurocosmetics was defined by Professor Misery in 1996, during his work on the relationship between the skin and the brain, as referring to cosmetic products capable of acting on skin cells by modulating the neuro-immuno-cutaneous system. In 2000, Professor Misery described neurocosmetic products as products applied to the skin but not absorbed, which manifest their activity on the cutaneous nervous system or their general effects on skin mediators.

[0009] Since then, cosmetology, that is, the science that studies the mechanisms of action of cosmetics, their biological effects on humans, and how to use them, has focused on the development of new neurocosmetic ingredients capable of improving the interactions between the skin and the nervous system. In particular, products are being sought that restore the skin's normal balance and, more generally, products that allow a dynamic return to physiological equilibrium correlated with a feeling of cutaneous "well-being" through the release of neurotransmitters induced by a physical, chemical, or emotional stimulus (2).

[0010] Neurocosmetic ingredients can act through various mechanisms, for example, directly on the nerve endings of cutaneous nerve fibers, as modulators of neurotransmitter release, notably through a "stroking" effect, namely very slight mechanical pressure on the mechanoreceptors that produce these neurotransmitters to transmit the "stroking" information to the brain. They can also modulate the functions of non-nerve cells by acting as agonist / antagonist molecules of neuropeptide receptors or as modulators of neurotransmitter effects.

[0011] In addition to the specific receptors for these neurotransmitters, as well as the enzymes that degrade them, being expressed by skin cells, the binding of neurotransmitters to specific receptors induces the modulation of cell properties and skin functions. Through these close links, the nervous system actively and significantly participates in maintaining skin balance and physiological homeostasis. Serotonin produced in Merkel cells has neurotransmitter properties and is capable of transmitting a positive message from the skin to the brain (for example, the "sensation of being caressed") and exerting a beneficial (neuroprotective) effect on the sensory neurons present in the skin.

[0012] Among cosmetic products, which include products for makeup, hygiene and skin care, this last category is more particularly targeted by neurocosmetics, especially for the following effects: anti-aging, anti-wrinkle, toning, soothing effect on skin that has undergone stress, and eudermic action, i.e. products that cause a feeling of well-being when applied to the skin.

[0013] As an example of a neurocosmetic ingredient, we can cite menthol and its derivatives which act on the skin to cool or warm it depending on the formulation used, the quantity and the area of ​​application.

[0014] Neurocosmetic ingredients were developed following the observations mentioned above that sensory neurons, just like epidermal cells, secrete multiple substances, neurotransmitters, which foster a permanent dialogue between the skin and the nervous system.

[0015] We already know the active ingredient DEFENSIL®-SOFT marketed by the Rahn company which contains an extract of Albatrellus confluens and which acts as a neuro-soothing agent by prolonging the zone of well-being of stressed and irritated skin, this active ingredient is described as preventing sensitization of the TRPV1 receptor by blocking serotonin receptors.

[0016] The problem posed at the origin of the present invention was to propose new neurocosmetic products, capable of stimulating cutaneous sensory neurons in order to give the skin a feeling of well-being, comforting. Summary of the invention

[0017] The inventor has shown that a solution to the technical problem of proposing new cosmetic products exhibiting neurocosmetic properties could be provided by means of a composition comprising a particular Pickering emulsion.

[0018] According to a first aspect, the present invention relates to the cosmetic, non-therapeutic, topical use of a composition as a neurocosmetic agent, said composition comprising a Pickering O / W emulsion containing an aqueous phase, a vegetable oil phase and an organomodified phyllosilicate.

[0019] According to a second aspect, the present invention aims at the cosmetic, non-therapeutic, topical use of said composition to provide the skin with a comforting effect, a feeling of well-being.

[0020] According to a third aspect, the present invention relates to the cosmetic, non-therapeutic, topical use of said composition to improve skin hydration and / or improve skin radiance.

[0021] According to a fourth aspect, the present invention relates to the cosmetic, non-therapeutic, topical use of said composition to give the skin a smoother, clearer and / or more uniform appearance.

[0022] According to a fifth aspect, the present invention relates to the cosmetic, non-therapeutic, topical use of said composition for its anti-aging, anti-wrinkle and / or anti-spot effect.

[0023] According to a fifth aspect, the present invention relates to a cosmetic, non-therapeutic skin treatment method, comprising at least one step of applying to the skin a neurocosmetic composition comprising a Pickering O / W emulsion containing an aqueous phase, a vegetable oil phase and an organomodified phyllosilicate.

[0024] The cosmetic compositions used according to the invention provide a lasting, comforting, and soothing effect, and create a feeling of well-being. They also improve skin hydration and maintain or restore radiance to the complexion, as well as balance the skin's surface by specifically addressing dryness in the driest areas and without adding oil to oily areas. This balancing effect helps reduce contrasts in the skin, thus giving it a more even and smoother appearance. Furthermore, publication (3) confirms the role of serotonin in its anti-aging action on the skin.

[0025] The cosmetic compositions used according to the invention are also stable, non-irritating, non-toxic, and non-allergenic to the skin.

[0026] Other aspects, advantages, properties of the present invention are presented in the description and examples that follow. Detailed description

[0027] Definitions

[0028] In this text, unless otherwise specifically indicated, percentages are expressed as a percentage of a reference composition.

[0029] In the present text, intervals are defined abbreviatedly to avoid describing each and every value within the interval; however, any suitable value within the interval may be chosen as the upper, lower, or terminal values ​​of the interval. For example, an interval from 0.1 to 1.0 represents the terminal values ​​of 0.1 and 1.0, as well as the intermediate values ​​of 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and all intermediate intervals within 0.1 to 1.0, such as 0.2 to 0.5, 0.2 to 0.8, 0.7 to 1.0, and so on.Unless otherwise specified, an interval defined as "between value A and value B" includes both values ​​A and B and is therefore equivalent to an interval "from value A to value B". The expression "at least" includes the value stated after it, for example, "at least 5%" should be understood as also including "5%". The expression "a maximum of" includes the value stated after it, for example, "a maximum of 5%" should be understood as also including "5%".

[0030] Furthermore, in the present text, measurable values, such as a quantity, should be understood as including standard deviations which can be easily determined by a person skilled in the art in the relevant technical field. Preferably, these values ​​are intended to include variations of ± 5%.

[0031] By "skin" is meant the epidermis of the face or body or scalp.

[0032] The compositions according to the present invention are cosmetic, non-therapeutic compositions. Cosmetic compositions are intended to be applied to healthy skin to treat the epidermis. They comply with EC Regulation 1223 / 2009.

[0033] By “neurocosmetic” is meant an agent which, when applied to the skin, exhibits activity on the cutaneous nervous system or general effects on skin mediators.

[0034] In particular, neurocosmetic agents are not generally absorbed through the skin; in the context of the invention, they act rather by stimulating cutaneous neurons through slight pressure.

[0035] For the purposes of the present invention, the skin mediator involved is serotonin, also called 5-hydroxytryptamine (5-HT), which is a neurotransmitter known to facilitate communication between neurons in the central nervous system.

[0036] Without wishing to be bound by any particular theory, it appears that applying the composition containing a specific Pickering emulsion to the skin stimulates cutaneous neurons and produces a feeling of well-being. This effect, conferred by the galenic structure of the composition, is biomimetic to the comfort provided by a light caress or the action of blowing on a scratch; this effect can also be called the "caress effect."

[0037] This effect is particularly pronounced when the composition is applied by spraying. The fine droplets remain on the skin's surface, thus mimicking corneocytes. The slight pressure exerted on the skin stimulates mechanoreceptors and releases neuropeptides that send signals to the brain similar to those of a light, pleasant caress. This signal is capable of suppressing any discomfort sent to the brain and replacing it with a message of well-being.

[0038] Pickering emulsions

[0039] Pickering emulsions are emulsions stabilized by solid particles. During the preparation of the emulsion, said solid particles position themselves at the interface between the aqueous phase and the oily phase.

[0040] The Pickering emulsions used according to the present invention are oil-in-water emulsions, i.e., H / W, stabilized by a particular clay which is a modified natural phyllosilicate.

[0041] Advantageously, the aqueous phase of the Pickering emulsion is present in an amount ranging from 43% to 93%, preferably 55% to 70% and preferably 58% to 65% by weight relative to the total weight of the composition.

[0042] According to a preferred embodiment, the modified natural phyllosilicate comprises a phyllosilicate selected from the group consisting of vermiculites and smectites. Preferably, the phyllosilicate may be selected from the group consisting of montmorillonites, bentonites, nonytronites, beidellites, volkonskoites, hectorites, saponites, sauconites, sobockites, stevensites, svinfordites; preferably, these are phyllosilicates of sodium, potassium, calcium, or mixtures thereof. More preferably, the phyllosilicate is selected from the group consisting of hectorite, montmorillonite, bentonite, or mixtures thereof.

[0043] According to a preferred embodiment, the modified natural phyllosilicate comprises an organic compound selected from the group consisting of xanthan gum, guar gum, tara or locust bean gum, acacia gum, carrageenan, alginate, chitosan, pectin, citric acid, tartaric acid, oxalic acid, succinic acid, malic acid, acetic acid, lactic acid, propionic acid, salicylic acid, and glycosaminoglycans. Advantageously, the modified natural phyllosilicate comprises bentonite modified by xanthan gum and citric acid.

[0044] According to another embodiment, the modified natural phyllosilicate comprises an organic compound selected from any organic compound known in the art of Pickering emulsions, such as those disclosed in French patent no. FR 2 976 503.

[0045] Advantageously, the modified phyllosilicate is present in an amount ranging from 2% to 20%, preferably 2.5% to 10% and preferably 3.5% to 8% by weight relative to the total weight of the composition.

[0046] According to a preferred embodiment, the vegetable oil phase of the Pickering emulsion comprises at least one vegetable oil selected from the group consisting of sunflower oil, rapeseed oil, olive oil, camelina oil, peanut oil, coconut oil, grapeseed oil, castor oil, argan oil, Djansang oil, desert date oil, nigella oil, prickly pear oil, macadamia oil, soybean oil, palm and palm oil, Tamanu oil, sesame oil, linseed oil, walnut oil, hazelnut oil, baobab oil, passion fruit oil, Brazil nut oil, hibiscus oil, pumpkin seed oil, and oil of Luffa, Carapa oil, Evening Primrose oil, Borage oil, Avocado oil, Almond oil, Sea buckthorn oil, Apricot kernel oil, Cherry kernel oil, Apple seed oil, Pomegranate oil, Jojoba oil,rosehip oil, plum oil, shea butter, cocoa butter, kokum butter, mango butter, moabi butter, karanja butter, tucuma butter, cupuaçu butter, buriti butter, the, Murumuru butter, Kombo butter, Kpangnan butter, caprylic / capric acid triglycerides.

[0047] Advantageously the composition used in the present invention does not include hemp oil extract.

[0048] Advantageously, the oily phase of the Pickering emulsion is present in an amount ranging from 5% to 40%, preferably 10% to 30% and preferably 15% to 25% by weight relative to the total weight of the composition.

[0049] Composition

[0050] The composition usable according to the invention is preferably a sprayable composition in fine droplets.

[0051] Preferably, the composition usable according to the invention comprises from 43 to 93% by weight of water relative to the total weight of the composition.

[0052] Advantageously the composition according to the present invention comprises, in an acceptable medium, at least one cosmetic agent selected from humectants, thickeners, texturizing agents, emulsifiers, dispersing agents, foaming agents, emulsifiers, preservatives, colorants, plant extracts, plant fibers, minerals, pH correcting agents, active ingredients and perfumes.

[0053] Advantageously the composition according to the present invention comprises from 0.001 to 20% by weight of at least one cosmetic agent relative to the total weight of the composition.

[0054] Of course, a person skilled in the art will take care to choose these cosmetic agents so as not to alter the properties of the composition usable according to the invention, in particular so as not to alter the properties giving this composition its vaporizable character.

[0055] The composition according to the invention may constitute a massage composition, a skin care composition, and in particular a cleansing, protective, treatment or care cream for the face, for the hands, for the feet, or for the body, in particular the composition may be a day cream, night cream, makeup remover cream, foundation cream, sunscreen cream; a fluid foundation, a makeup remover milk, a protective or care body milk, a sunscreen milk; a lotion, gel or foam for skin care, such as a micellar cleansing lotion.

[0056] Advantageously, the process for preparing the composition according to the invention comprises at least the following steps in this order: - prepare the aqueous phase; - add the organomodified phyllosilicate to the aqueous phase and mix; - add the vegetable oil phase to the mixture obtained and obtain a Pickering oil / water emulsion.

[0057] Uses

[0058] Advantageously, the use according to the invention is such that the composition is applied by spraying.

[0059] The following examples are intended to illustrate the invention without limiting its scope. Examples

[0060] A-Cosmetic compositions

[0061] Table 1 lists the products used to prepare composition A usable according to the invention.

[0062] [Tables 1] Phase Commercial name % INCI A Water Qsp Aqua A Frametime CXG marketed by Ephyla 2.50 Bentonite & xanthan gum & Sodiu m stearoyl glutamate & citric acid B Refined sunflower oil commercially Used by CAUVIN 8.00 Helianthus annuus seed oil C Georgard Ultra marketed by L onza 1.00 Gluconolactone & Sodium benzoat e & Calcium gluconate C Sodium benzoate m 0.30 Sodium benzoate Total 100

[0063] The constituents of phase A were mixed at 20°C with a mechanical knife mixer or a rotor stator at a speed of 4000 rpm for 10 minutes so as to implement sufficient shear and dispersion to obtain homogenization of the phase.

[0064] Phase B was then incorporated, still at 20°C, on the same shearing pattern gradually over 10 minutes.

[0065] The Pickering emulsion was thus prepared. The temperature of the mixture, under shear, was then increased to reach 50°C in order to solubilize the preservative.

[0066] Phase C (preservatives) was then introduced at this temperature of 50°C under a more moderate stirring of 2000 rpm.

[0067] The product is cooled to room temperature.

[0068] Finally, the pH was adjusted to 4.9.

[0069] The formulation of the resulting composition comprises fine oil droplets coated with bentonite platelets. These mineral platelets are stable at the oil / water interface; they are formed by the exfoliation of bentonite (Frametime CXG) under the action of mechanical shear and form oil microcapsules. The dispersion of the microcapsules is stable when the product is at rest, even if its viscosity is low.

[0070] The size of the microcapsules is on the order of 5 to 15 106 m in diameter, which allows this galenic to pass through standard type spray nozzles in cosmetics.

[0071] This composition has thus been sprayed onto healthy skin, it can then be gently massaged to perfect the spreading on the skin or preferably, it can be left in the form of a fine mist on the surface of the skin.

[0072] Table 2 lists the products used to prepare composition B usable according to the invention.

[0073] [Tables2] Phase Trade name % INCI A Water 73.70 Aqua B Georgard Ultra marketed by Lo nza 1.00 Gluconolactone & Sodium benzoate & Calcium gluconate B Sodiu m benzoate 0.30 Sodium benzoate C Frametime CX marketed by Ep hyla 4.50 Bentonite & xanthan gum & citric acid C Xanthan gum FF commercially Used by Jungbunz lauer 0.50 xanthan gum D Capric / caprylic acid triglyceride 20.00 Caprylic / capric triglyceride Total 100

[0074] Preparation of composition B:

[0075] Phases A and B were mixed to form an aqueous phase, then phase C was added and the mixture was blended. Finally, the oily phase D was added and the mixture was blended. Once the Pickering emulsion was obtained, the pH was adjusted to 5.00.

[0076] The formulation of the resulting composition comprises fine oil droplets coated with bentonite platelets. These mineral platelets are stable at the oil / water interface; they are produced by the exfoliation of bentonite (Frametime CXG) under the action of mechanical shear and form oil microcapsules. The dispersion of the microcapsules is stable when the product is at rest, and its viscosity corresponds to that of a cream that fits in a standard cream jar.

[0077] This composition was manually applied to the healthy skin of a forearm. The applied cream provides a lasting, comforting, and soothing effect and gives a feeling of well-being.

[0078] This type of "microencapsulated" formulation allows for the application or misting of a layer of microcapsules containing skin-care lipid molecules. As they dry, the microcapsules gradually release the skin-care lipid molecules (the oil phase), providing a long-lasting moisturizing and nourishing effect, improving skin hydration, and maintaining or restoring the skin's radiance as more microcapsules are released.

[0079] Depending on the skin type, the microcapsules release their contents more or less quickly: the drier the skin, the faster the microcapsules release their contents; on a so-called combination skin (with an oily area and a dry area), the microcapsules release their contents quickly in the dry area, while in the oily area the microcapsules remain intact for a longer period. Thus, the formulation helps to balance the skin's surface by specifically addressing the dryness of the driest areas and by not adding any oil to the oily areas.

[0080] This balancing effect allows the skin to reduce contrasts, thus giving it a more uniform and smoother appearance. This "scrubbing" effect on imperfections (accentuated by contrasts that create a more defined skin texture) gives the skin a younger and more relaxed look. User comfort is enhanced by the gradual release of skincare microcapsules according to the skin's needs.

[0081] B- Measurement of the neurocosmetic effect on human skin expiants by measuring the increase in serotonin production

[0082] Merkel cells in the skin release neurotransmitters, particularly serotonin, to transmit information about a "caressing" touch to the brain via the underlying nerve fiber. This is how mechanoreceptors (Merkel cells or Merkel discs) ensure the sense of touch, especially positive sensations; it involves transcribing a mechanical effect, namely a "caressing" touch, into chemical message, namely serotonin, a neurotransmitter that the brain associates with well-being

[0083] This study is based on the ability of the composition according to invention A to increase serotonin production.

[0084] The desired effect is a stimulating effect on the production of serotonin which results in a comforting effect, a feeling of well-being, a caressing effect on the epidermis which is in contact with the external environment.

[0085] Tested compositions

[0086] Composition A is used as the composition according to the invention.

[0087] For comparison purposes, the following were used: - physiological saline, i.e. a 0.9% NaCl composition, as a baseline control (BC) and - of del-naphthyl isothiocyanate at a concentration of 0.25% (V / V) as a positive control (TP).

[0088] Principle of the study

[0089] For this study, normal fresh human skin expiants with Merkel cells are incubated for 20 hours at 32°C for acclimatization.

[0090] Then the explant samples to be tested -in triplicate- are treated by spraying with composition A used in accordance with the invention or by spraying with the control compositions TB and TP and placed back into incubation at 32°C.

[0091] After 3 hours, a first series of treated explant samples was recovered and the treated explants were dissected and prepared: placed in liquid nitrogen for 3 minutes, then in 10 mL of ice-cold PB S IX and then in an ultrasonic bath for 45 minutes to obtain a cell lysate.

[0092] After this treatment carried out for each implant, 2mL of cell lysate from each explant sample of this first series were taken and 1% of stabilizing agent was added to preserve them at -20°C until the Elisa assay was carried out.

[0093] The expiants treated for 3 hours using compositions A, TB and TP are respectively named A3, TB3 and TP3.

[0094] After 8 hours, a second set of treated explant samples was collected and treated as above. Then, 2 mL of cell lysate from each explant sample in this second set was taken, and 1% stabilizing agent was added to preserve them at -20°C until the ELISA assay was performed.

[0095] The expiants treated for 8 hours with compositions A, TB and TP are respectively named A8, TB8 and TP8.

[0096] At the time of carrying out the Elisa assay, the treated explant samples were subjected to a new ultrasonic bath for 35 minutes and then, after homogenization, the supernatants were recovered for the purpose of carrying out the Elisa -serotonin test.

[0097] ELISA test system - serotonin

[0098] The standard and control solutions were prepared in accordance with the instructions for the Elisa - serotonin kit (commercial reference of the kit: Serotonin Research ELISA ® marketed by Immusmol).

[0099] The kit provides a practical test for the determination of the serotonin concentration of media comprising prepared skin explant supernatants, thus allowing the modulatory effect of the topical composition to be tested to be evaluated.

[0100] This kit implements an ultrasensitive enzymatic immunoassay method for the quantitative determination of serotonin. Serotonin is acylated and then detected by antigens bound to the solid phase of the microtiter plate. Standards, controls, and acylated samples, along with analytes bound to the solid phase, compete for a fixed number of antibody-binding sites. Once the system is in equilibrium, the free antigen and free antigen-antibody complexes are removed by washing. The antibody bound to the solid phase is detected by an anti-rabbit IgG-peroxidase conjugate using TMB ((3,3',5,5'-Tetramethylbenzidine)) as a substrate. This is therefore a colorimetric assay, the color reaction of which is revealed at 450 nm. Quantification of unknown samples is obtained by comparing their absorbance with a standard curve prepared with known standard concentrations.

[0101] Results

[0102] Standard range

[0103] For this study, a serotonin calibration curve ranging from 0.0 to 2.5 × 10⁹ g / mL (ng / mL) was established. The absorbances of the serotonin calibration curve at 450 nm are presented in Table 3.

[0104] [Tables3] DO450nm White SO Standards = Serotonin Range (109 g / mL) SI = 0.00 0 S2 = 0.015 S3 = 0.05 0 S4 = 0.150 S5 = 0.2 50 Replicat 1 12.545 11.633 11.095 9.839 6.903 4.309 Replicat 2 12.555 11.698 10.982 9.679 7.263 3.895 Replicat 3 13.053 12.929 9.643 9.074 6.760 4.182 Average 12.718 12.087 10.573 9.531 6.975 4,129 Standard deviation 0.290 0.730 0.807 0.403 0.259 0.212

[0105] The equation of the calibration curve is: y = 28.673x² - 25.137x + 12.393 The coefficient of determination is: R² = 0.9719

[0106] Measurement of samples

[0107] The absorbance (OD) results at 450 nm with standard deviations of conformal composition A and controls TB and TP at 3 hours and 8 hours, as well as the percentage (%) increase compared to the baseline control, are presented respectively in Table 4 below.

[0108] [Tables4] OD 450 nm of composition A and controls and standard deviation TB3 TP3 A3 TB8 TP8 A8 OD 450 nm 0.204 0.340 0.246 0.203 0.254 0.246 Standard deviation 0.020 0.031 0.028 0.026 0.060 0.025 % increase compared to baseline control 0 66.67 20.58 0 25.12 21.18

[0109] Under the study conditions, the kinetics of the positive response with respect to the time of contact with the skin expiants show that the expected peak stimulation with the positive control (del-naphthyl isothiocyanate) is observed after 3 hours of contact, with 66.67% more serotonin produced compared to the skin expiant control without the test product. This positive response to the positive control validates the experiment. After 8 hours of contact, the positive effect of the positive control decreases very significantly; the effect is decreasing between 3 and 8 hours of contact.

[0110] With composition A according to the invention, the increase in serotonin production, compared to the baseline control TB3, is 20.58% (A3) after 3 hours (A3), and remains the same after 8 hours (21.18% for A8). The positive effect of the composition according to the invention is therefore stable over time, which demonstrates the persistence of this positive effect.

[0111] Conclusion:

[0112] The composition according to the invention A applied to the exposed expiants stimulates the production of serotonin by more than 20% compared to the baseline control after 3 hours of contact (A3) with the expiant, this production is maintained at +21% compared to the baseline control after 8 hours of contact (A8).

[0113] It is recalled that in the skin, Merkel cells are the mechanoreceptors on the front line of the sense of touch, as well as the main cells capable of producing serotonin in significant quantities. Serotonin is a neurotransmitter of the sensation of caressing which, via the nerve fibril underlying the Merkel cells, informs the brain that a pleasant and positive sensation.

[0114] Thus, the composition according to the invention A, by increasing the production of the neuro-mediator serotonin, informs the brain of a positive modulation of the caress type or positive sensory effect.

[0115] The composition according to invention A, by increasing the production of the neurotransmitter serotonin, also has an anti-aging effect.

[0116] BIBLIOGRAPHY 1. Effects on tactile transmission by serotonin transporter inhibitors at Merkel dis es ofmouse whisker hair follicles, Chang and G Gu, Molecular Pain vol. 16:1-9, May 20, 2020; 2. Neurocosmetics in Skincare - The Fascinating World of Skin-Brain Connection: A Review to Explore Ingredients, Commercial Products for Skin Aging, and Cosmetic Regulation. Rizzi, V.; Gubitosa, J.; Fini, P.; Cosma, P. Cosmetics 2021, 8, 66. 3. . The effects of skin-derived oxytocin or serotonin on brain function and skin aging in mice. 2024. Doctoral dissertation. tf / M^ (Citation of the publication according to ISO 690).

Claims

Demands

1. Cosmetic, non-therapeutic, topical use of a composition as a neurocosmetic agent, said composition comprising a Pickering oil-in-water emulsion containing an aqueous phase, a vegetable oil phase and an organomodified phyllosilicate.

2. Use according to claim 1 wherein the organomodified phyllosilicate is present in an amount from 2% to 20%, preferably 2.5% to 10% and preferably 3.5% to 8% by weight relative to the total weight of the composition.

3. Use according to any one of claims 1 or 2 wherein the aqueous phase of Pickering's emulsion is present in an amount from 43% to 93%, preferably 55% to 70% and preferably 58% to 65% by weight relative to the total weight of the composition.

4. Use according to any one of claims 1 to 3, wherein the vegetable oil phase of the Pickering emulsion comprises at least one vegetable oil selected from the group consisting of sunflower oil, rapeseed oil, olive oil, camelina oil, peanut oil, coconut oil, grapeseed oil, castor oil, argan oil, Djansang oil, desert date oil, nigella oil, prickly pear oil, macadamia oil, soybean oil, palm and palm oil, Tamanu oil, sesame oil, linseed oil, walnut oil, hazelnut oil, baobab oil, passion fruit oil, Brazil nut oil, hibiscus oil, oil of pumpkin seed oil, luffa oil, carapa oil, evening primrose oil, borage oil, avocado oil, almond oil, sea buckthorn oil, apricot kernel oil, cherry kernel oil, apple seed oilPomegranate oil, jojoba oil, rosehip oil, plum oil, shea butter, cocoa butter, kokum butter, mango butter, moabi butter, karanja butter, tucuma butter, cupuaçu butter, buriti butter, murumuru butter, kombo butter, kpangnan butter, caprylic / capric acid triglycerides.

5. Use according to any one of claims 1 to 4 wherein the oily phase of Pickering's emulsion is present

6.

7.

8.

9.

10.

11.

12. in an amount ranging from 5% to 40%, preferably 10% to 30% and preferably 15% to 25% by weight relative to the total weight of the composition. Use according to any one of claims 1 to 5 comprising, in an acceptable medium, at least one cosmetic agent selected from humectants, thickeners, texturizing agents, emulsifiers, dispersing agents, foaming agents, emulsifiers, preservatives, colorants, plant extracts, plant fibers, minerals, pH correctors, active ingredients and perfumes. Use according to any one of claims 1 to 6, wherein the composition is applied by spraying. Use according to any one of claims 1 to 7 to provide the skin with a comforting effect, a feeling of well-being. Use according to claims 1 to 7 to improve skin hydration and / or enhance skin radiance. Use according to claim 1 to 7 to give the skin a smoother, clearer and / or more even appearance. Use according to claim 1 to 7 for its anti-aging, anti-wrinkle and / or anti-spot effect. A cosmetic, non-therapeutic skin treatment process comprising at least one step of applying to the skin a neurocosmetic composition comprising a Pickering oil-in-water emulsion containing an aqueous phase, a vegetable oil phase and an organomodified phyllosilicate.