Novel GABA-rich extract and use thereof in cosmetics and / or dermatology

Abstract

The present invention relates to a natural extract, preferably a yeast extract, which is rich in gamma-aminobutyric acid (GABA), to a cosmetic and / or dermatological product comprising such an extract, and to the use thereof for the beneficial effects they have on the skin.

Description

[0001] NEW GABA-RICH EXTRACT AND ITS USE IN COSMETICS AND / OR DERMATOLOGY

[0002] technical field

[0003] The present invention falls within the field of cosmetics and dermatology, seeking natural solutions to improve skin properties. The solution proposed in this application is the provision of a natural extract rich in GABA, whose beneficial properties for the skin are well-known. Thus, incorporating such an extract into a cosmetic composition makes it possible to obtain a product with a range of positive effects for the skin.

[0004] Prior state of the art

[0005] The skin is the body's largest organ, representing 16% of total body weight. It serves as the first line of defense, maintaining essential chemicals and nutrients. It has been established that the skin undergoes age-related changes due to a combination of intrinsic factors, which occur naturally over time, and extrinsic factors, which result from external stressors such as UV radiation and pollution. These factors can lead to dryness or inflammation of the epidermis, decreased proliferation and function of fibroblasts in the dermis, loss of elasticity, and the formation of wrinkles. Keratinocytes, which make up the majority of epidermal cells, are distinguished by their synthesis of cytokeratin and the presence of desmosomes. They are also tightly bound to one another to form a robust physical and chemical barrier.The dermis also contains abundant fibroblasts, which play a key role in many physiological skin reactions by producing connective tissue in the dermis and linking other cells. Age-related aging is associated with epidermal atrophy and a reduction in the number of fibroblasts and in the quantity and quality of collagen in the dermis, which are the main histological changes in the skin. Intrinsically aged skin is characterized by decreased epidermal turnover, a phenomenon associated with a narrowing of the stratum spinosum.

[0006] Gamma-aminobutyric acid (GABA), a non-proteinogenic amino acid, is naturally produced by the body. GABA is present in large quantities in vertebrates, plants, and microbes, and it is the primary inhibitory neurotransmitter in the adult brain. GABA is present in synaptic vesicles in the nervous system and then released into the synaptic cleft, where it diffuses to target receptors on the postsynaptic surface. GABA has a relatively low molecular weight, which allows it to cross the skin and bind to GABA receptors on skin cells. It has thus been found to play a role in several skin functions: (1) the production of hyaluronic acid; (2) the ability of normal human keratinocytes to maintain cell volume homeostasis under UV radiation; and (3) the ability of dermal fibroblasts to survive when exposed to oxidative stress.

[0007] Thus, this research suggests that GABA could have beneficial effects on the skin due to its anti-inflammatory and antioxidant properties. GABA could improve skin resilience to age-related stresses or environmental exposure (light, pollution, etc.) (Zhao et al., Biomol Ther (Seoul). 2023 Nov 1;31(6):640-647. doi: 10.4062 / biomolther.2023.085. Epub 2023 Aug 1. PMID: 37524442). GABA could also regulate melanin production and therefore skin pigmentation (Ceol, Craig J. (2023) Cancer Discov, vol. 13, no. 10, pp. 2128-2130. DOI: 10.1158 / 2159-8290.CD-23-0843). Preliminary studies have also examined the role of GABA in regulating sebum production, which could be relevant for people with acne-prone skin. Finally, GABA also has muscle-relaxing properties, which may suggest anti-wrinkle benefits.

[0008] Document CN114292763 describes a new yeast strain that produces high amounts of GABA and the use of an extract from this strain to combat wrinkles. Document KR2018-0020534 describes the use of a GABA-producing yeast, in extract form, for hair regrowth. The database document "Neuro GABA Body Balm" describes a rejuvenating balm containing GABA. Document US2009 / 068150 describes a culture of lactic acid bacteria in a medium containing mung bean extract and glutamic acid.

[0009] However, there is a clear need to develop new natural cosmetic ingredients to improve the condition of the skin.

[0010] The solution proposed by the present invention is to provide a natural extract containing gamma-aminobutyric acid (GABA) in a complex matrix (inactivated bacteria, peptides, amino acids, RNA, etc.). Thus, the integration of such an extract into a product to be applied to the skin makes it possible to provide a sufficient quantity of GABA to obtain a beneficial effect on human skin, in a natural context also rich in other potentially useful compounds (in terms of hydration, antioxidant potential, etc.). Detailed description of the invention

[0011] Thus, according to a first aspect, the present invention relates to a natural extract rich in gamma-aminobutyric acid (GABA).

[0012] For the purposes of this invention, a "GABA-rich extract" is defined as an extract containing at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10%, or even at least 11, 12, 13, 14, or even at least 15% by weight of GABA, the percentage by weight being expressed relative to the dry weight of the extract. Advantageously, the extract contains at least 5% by weight of GABA. A content between 5 and 15% is particularly suitable for the purposes of this invention.

[0013] In the context of the invention, a natural extract is defined as one obtained from an element of nature, in particular from plant matter or from a microorganism such as a yeast or a bacterium. According to a particular embodiment, the extract according to the invention is obtained from a yeast, hereinafter referred to as "yeast extract" ("YE" for Yeast Extract).

[0014] In general, yeast extracts are products known to those skilled in the art. According to the invention, "yeast extract" (or "yeast hydrolysate" or "yeast peptone") refers to the soluble fraction obtained after thermal, mechanical (using known methods such as high-pressure homogenization, mechanical milling, mechanical lysis using glass beads, ultrasonic disintegration, repeated freeze-thaw cycles, or osmotic shock), or enzymatic lysis (using an enzyme exogenous or endogenous to the yeast)... The objective of such lysis is to release the internal macromolecules of said yeast in their native state, in particular the pool of free amino acids, including free glutamic acid. The resulting co-products correspond to the insoluble fraction called "yeast hulls" and can be used in other processes.The processes for obtaining yeast hulls and yeast extracts are well known in the art (see, for example, the reference work “Yeast Technology”, 2nd edition, 1991, G. Reed and TW Nogodawithana, published by Van Nostrand Reinhold, New York, ISBN 0-442-31892-8). The insoluble and / or soluble fractions can then be dried.

[0015] Thus, a yeast extract can be in dry form, preferably as a fine, water-soluble powder, in liquid form, even as a concentrated liquid, or in paste form. A yeast extract consists mainly of protein, preferably at least 55% protein. The challenge overcome by the present invention is to obtain a natural extract rich in GABA without the addition of exogenous GABA. Indeed, some vegetables, such as broccoli or sweet potatoes, contain GABA, but in very small quantities, which are not usable for the desired properties.

[0016] Advantageously, the natural extract used in the context of the present invention is an extract naturally rich in glutamic acid (or glutamate). It should be noted that, in the context of this invention, "glutamic acid" (or "glutamate") refers to the amino acid in its free form, not incorporated into a peptide or protein.

[0017] In particular, an extract is said to be "rich in glutamic acid" if it contains at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10%, or even 11, 12, 13, 14, 15, 20, or 25% by weight of free glutamic acid, the percentage by weight being expressed relative to the dry weight of the extract. Advantageously, the extract comprises at least 10% by weight of free glutamic acid. A content between 5 and 25%, for example between 10 and 20%, is particularly suitable for the purposes of the present invention. Natural extracts meeting this definition include, for example, yeast extracts, bacterial extracts, or plant extracts, advantageously yeast extracts.

[0018] According to a particular embodiment, such an extract is obtained from an organism, especially a plant or microorganism such as yeast or bacteria, capable of synthesizing or even secreting glutamic acid, advantageously in large quantities. As is known to those skilled in the art, the organism, advantageously a yeast, may be naturally capable of synthesizing glutamic acid in large quantities, or genetically modified for this purpose. Alternatively, glutamic acid present in the medium may be transported into and by the organism, advantageously a yeast.

[0019] Thus, and according to a particular aspect, the present invention relates to a yeast extract containing gamma-aminobutyric acid (GABA), said GABA being obtained from glutamic acid present as a free amino acid in said yeast.

[0020] An extract according to the invention differs from synthetic or purified GABA in that it also contains the components of the natural extract, in particular yeast extract, thus constituting an enriched form.

[0021] A yeast extract according to the invention can be obtained from any yeast, advantageously meeting the above definition. Preferably, the yeast strain used for preparing the extract according to the invention belongs to the genus Saccharomyces, Kluyveromyces, or Candida (also known as Pichia or Lindnera). Preferably, the yeast strain used for preparing the extract belongs to the genus Saccharomyces, and more particularly to the species Saccharomyces cerevisiae.

[0022] Obtaining GABA from glutamic acid involves the activation of glutamate decarboxylase (GAD) activity capable of ensuring the following conversion:

[0023] L-Glutamate + H+ GABA + CO2

[0024] In another aspect, the invention relates to a process for obtaining an extract, advantageously a yeast extract as described above, and the extract thus obtained. Advantageously, such a process comprises the following steps:

[0025] - preparation of yeast extract from yeast containing glutamic acid in the form of a free amino acid;

[0026] - incubation of the extract in the presence of a glutamate decarboxylase (GAD) enzyme.

[0027] At the end of this process, the extract obtained is low in glutamic acid, or even free of glutamic acid. In the context of the invention, "low-glutamic acid extract" means an extract that advantageously comprises less than 10%, or even less than 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, or even 0.2 or even 0.1% by weight of glutamic acid in free form, the percentage by weight being expressed relative to the dry weight of the extract. "Glutamic acid-free or glutamic acid-deprived extract" means an extract that does not contain glutamic acid in free form, corresponding to the case where all the free glutamic acid present in the extract has been converted to GABA.

[0028] As is known to those skilled in the art, a natural extract, advantageously a yeast extract, can be incubated in the presence of such an enzyme under conditions, particularly of temperature and pH, that ensure this conversion. These conditions vary depending on the origin of the GAD enzyme. For example, and in relation to the enzyme produced by Levilactobacillus brevis, these conditions are:

[0029] - an acidic pH, for example of 5; and

[0030] - a temperature between 30 and 35°C, for example equal to 33°C.

[0031] Alternatively, a natural extract, advantageously a GABA-rich yeast extract according to the invention, is obtained via a bacterium exhibiting suitable glutamate decarboxylase activity.

[0032] Thus, the bacterium used in the invention exhibits glutamate decarboxylase (GAD) activity; in other words, it is capable of producing a glutamate decarboxylase (GAD) enzyme. The proteins involved in this metabolic pathway, in particular the GadA and / or GadB genes encoding the enzyme and the GadC gene encoding the substrate transporter, are widely documented in the prior art; see, for example, the review by Yogeswara et al. (Microorganisms 2020, 8(12), 1923; https: / / doi.org / 10.3390 / microorganisms8121923) in relation to lactic acid bacteria.

[0033] According to a particular embodiment, a bacterium of interest carries a GadA and / or GadB gene encoding the GAD enzyme.

[0034] According to another embodiment, the bacterium also carries a GadC gene encoding a glutamate and GABA transporter.

[0035] These can be endogenous or exogenous genes, single or multicopy, chromosomally integrated or carried by a plasmid, and placed under the control of regulatory elements allowing their expression, such as a promoter. In a particular embodiment, they are called endogenous genes.

[0036] It has been shown that lactic acid bacteria, particularly those of the Lactobacillaceae family, are especially well-suited for implementation within the scope of the present invention. The bacteria listed below can be used alone or in combination.

[0037] Bacteria carrying at least one GadA and / or GadB gene are chosen, for example, from the group including: Lactobacillus plantarum.

[0038] Bacteria carrying at least one GadA and / or GadB gene and at least one GadC gene are, for example, chosen from the group including the following genera: Levilactobacilus, Lentil actobacilus, Lactococcus, Lacticaseibacillus, Furfurilactobacillus, Leuconostoc, Lactiplantibacillus, Bifidobacterium, Pediococcus, Enterococcus and Limosilactobacillus.

[0039] It may for example be: Levilactobacilus brevis, Lentilactobacilus buchneri, Lactococcus lactis, Lacticaseibacillus paracasei, Furfurilactobacillus rossiae, Enterococcus faecium, Leuconostoc suionicum, Lactobacillus amylovorus, Lactiplantibacillus plantarum, Bifidobacterium dentium, Bifidobacterium adolescentis, Bifidobacterium angulatum, Pediococcus pentosaceus, Enterococcus cassetteliflavus, Limosilactobacillus reuteri, Enterococcus gallinarum, Limosilactobacillus oris, Pediococcus acidilactici, Limosilactobacillus fermentum and Enterococcus hermanniensis. As is well known to those skilled in the art, the bacterium is cultured under conditions favorable to the growth of bacteria of the Lactobacillaceae family, for example in an MRS (Man Rogosa, Sharpe) type culture medium. The culture conditions, particularly those relating to pH, temperature, and aerobic or anaerobic conditions (partial or total), depend on the strain chosen.As is known and as described in the examples, a strain of Levilactobacillus brevis is advantageously cultured under partially anaerobic conditions, at a temperature between 30 and 35°C and at a slightly acidic pH, for example 6.2.

[0040] Advantageously, the bacterium is further cultured under conditions that promote the expression of genes in the pathway, including GadA, GadB and / or GadC.

[0041] At the end of growth and for the conversion stage, the culture thus obtained can be used as is, or in dried or even freeze-dried form, provided that these treatments do not affect the enzymatic activity.

[0042] By using a bacterium equipped with the GadC-encoded transporter, whole cells can be implemented to ensure the conversion of glutamic acid from the natural extract into GABA.

[0043] Alternatively, and especially when the bacteria do not possess such a transporter, the bacteria are subjected to lysis, then possibly centrifuged, and it is the lysate containing the enzyme of interest, possibly purified, that is used.

[0044] The extract, advantageously of yeast, is then incubated with the bacterial culture, possibly in the form of a bacterial lysate.

[0045] According to one embodiment, the free glutamic acid titration of the extract, particularly of yeast, is adjusted. In practice, the extract is advantageously used in this incubation step at a concentration of at least 100, 150, 200, 250 or even 300 g / L, for example between 150 g / L and 250 g / L.

[0046] According to one embodiment, the conversion is ensured by contacting or incubating the extract, advantageously of yeast, as detailed above with the bacterium, namely the bacterial must or bacterial lysate, as described above.

[0047] Incubation is advantageously carried out under conditions adapted to the specific bacteria used, or to the enzyme in the case of a bacterial lysate. Thus, as is known to those skilled in the art, the incubation conditions are adjusted according to the bacterial strain and the enzyme present to ensure optimal conversion activity. In this sense, the medium and incubation conditions are conducive to enzymatic activity and are not intended to promote bacterial growth.

[0048] It should also be noted that in this stage, there can be no growth of the yeast since it is in extract form and therefore in an inactivated form.

[0049] According to one embodiment, the incubation medium is not a medium for bacterial culture and consists solely of yeast extract and bacterial culture, optionally lysed.

[0050] Other conditions suitable for this conversion stage are:

[0051] - a temperature between 30 and 40°C,

[0052] - a pH between 5 and 7;

[0053] - an incubation time of approximately 15 to 70 hours, preferably 24 to 70 hours.

[0054] The conversion step is carried out until the desired amount of free glutamic acid is consumed. For the purposes of this application concerning the use of the final extract for health, and assuming no GABA toxicity, the conversion to GABA must be optimal, advantageously exceeding 90%. As previously stated, the final extract advantageously comprises less than 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1%, or even 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or even 0.1% by weight of free glutamic acid, the weight percentage being expressed relative to the dry weight of the extract. Even more advantageously, all of the glutamic acid in the extract is consumed.

[0055] According to a particular embodiment, an extract according to the invention further has the following characteristics, expressed as a percentage by weight relative to the dry weight of the extract:

[0056] - a nitrogen content of 0 to 20%, for example 7 to 20%; and / or

[0057] - a free amino acid content of 0 to 30%, for example 10 to 20%; and / or

[0058] - a total amino acid content of 20 to 50%, for example 30 to 40%.

[0059] After the conversion process has stopped, several treatment schemes for the extract thus obtained can be considered: According to a first embodiment, and at least in the case of incubation with live bacteria, it is subjected to thermal inactivation, for example at a temperature of 90°C. In this case, the product obtained contains inactivated bacteria.

[0060] According to another embodiment, after this thermal inactivation step, the bacteria are removed from the extract by any technique known to those skilled in the art, for example by tangential membrane filtration (microfiltration or ultrafiltration), by centrifugation, or by a combination of these different techniques.

[0061] These steps may prove unnecessary in the case of the implementation of a bacterial lysate.

[0062] Thus, at this stage, the extract may contain inactivated bacteria or be free (or essentially devoid) of bacteria.

[0063] According to a particular embodiment, the inactivated bacteria are preserved in the extract according to the invention, thus constituting a post-biotic of interest in the context of an application particularly in cosmetics.

[0064] According to another characteristic, an extract according to the invention is water-soluble.

[0065] According to a particular embodiment, the extract thus obtained is dried, advantageously by spray drying, for example using a spray drying tower. In the context of this application, it has been shown that the GAB A present in the extract resists these heat treatments and remains stable.

[0066] In one particular embodiment, the extract according to the invention is in the form of a dry extract. Alternatively, it may be in liquid or powder form. In another particular embodiment, the extract according to the invention may be diluted in a physiologically acceptable carrier or excipient. A physiologically acceptable carrier or excipient is one that is aromatically neutral and suitable for administration in humans or animals. Examples of physiologically acceptable carriers or excipients include maltodextrins, triacetin, propylene glycol, vegetable glycerin, glycerol, soluble fibers, yeast derivatives such as yeast extracts, barks, and autolysates, and fats such as palm oil.

[0067] An extract according to the invention possesses properties beneficial to the beauty and health of the skin, of interest to any product intended for topical use. One aspect of the invention therefore relates to the use of such an extract in this context. The extract according to the invention can be used alone as an active ingredient or formulated in a cosmetic and / or dermatological composition. Another object of the invention therefore relates to the use of the extract according to the invention contained in a cosmetic and / or dermatological composition, which also includes at least one cosmetically and / or dermatologically acceptable excipient. In other words, and according to a particular aspect, the present invention relates to a cosmetic and / or dermatological composition for topical use comprising an extract as defined above.

[0068] For the purposes of this application, the term "excipient" refers to a substance or compound that possesses no biological and / or therapeutic properties. The excipient ensures the creation of a specific texture, fragrance, and / or color for a formulation, as well as its preservation, stability, safety, and longevity, in accordance with regulations. The excipient is distinct from the active compound(s) present in the composition according to the invention.

[0069] An "acceptable excipient" is defined as any vehicle or solvent suitable for use in contact with the skin, including the scalp and / or human mucous membranes, which is non-toxic, non-irritating, does not induce an allergic response, and is chemically stable.

[0070] As is known to the person in the trade, the excipient(s) may be chosen from: preservatives, emollients, emulsifiers, surfactants, moisturizers, thickeners, conditioners, mattifying agents, stabilizers, antioxidants, texturizing agents, gloss enhancers, film-forming agents, solubilizers, pigments, colorants and perfumes.

[0071] These excipients are preferably chosen from the group consisting of amino acids and their derivatives, polyglycerols, esters, polymers and cellulose derivatives, lanolin derivatives, phospholipids, lactoferrins, lactoperoxidases, sucrose-based stabilizers, vitamin E and its derivatives, natural and synthetic waxes, vegetable oils, triglycerides, unsaponifiables, phytosterols, vegetable esters, silicones and their derivatives, protein hydrolysates, jojoba oil and its derivatives, lipo / water-soluble esters, betaines, aminoxides, plant extracts, sucrose esters, titanium dioxides, glycines, and parabens.

[0072] Particularly in the cosmetic field, the group of excipients may consist of butylene glycol, steareth-2, steareth-21, glycol-15 stearyl ether, cetearyl alcohol, phenoxyethanol, methylparaben, ethylparaben, propylparaben, butylparaben, butylene glycol, natural tocopherols, glycerin, dihydroxyketyl sodium phosphate, isopropyl hydroxyketyl ether, glycol stearate, trisononanoin, octyl cocoate, polyacrylamide, isoparaffin, aureth-7, a carbomer, propylene glycol, glycerol, bisabolol, a dimethicone, sodium hydroxide, PEG-30 dipolyhydroxysterate, capric / caprylic jojoba, triglycerides, magnesium cetearyl sulfate octanoate, EDTA, dibutyl adipate, cyclomethicone, grape seed oil, grape gum, xanthan gum, citric acid oil, sodium lauryl sulfate, mineral waxes and oils, isostearyl isostearate, propylene glycol dipelargonate,Propylene glycol isostearate, PEG-8, beeswax, hydrogenated palm kernel oil glycerides, hydrogenated palm oil glycerides, lanolin oil, sesame oil, cetyl lactate, lanolin alcohol, castor oil, titanium dioxide, lactose, sucrose, low-density polyethylene, isotonic saline solution.

[0073] According to a particular embodiment, the extract represents from 0.01 to 10% by weight of the composition. In other words, a cosmetic composition according to the invention comprises the extract defined above advantageously at a level of 0.01% to 10% by total weight of the composition, even more advantageously from 0.1% to 5%, preferably between 1% and 3%.

[0074] The cosmetic composition may, in addition to the extract according to the invention, contain other active ingredients of interest.

[0075] In the context of this invention, the terms "active compound," "active ingredient," and "active principle" are used interchangeably and refer to a substance or compound that possesses biological and / or therapeutic properties underlying a physiological effect. The active compound, active ingredient, or active principle is distinct from the excipient(s) as defined above.

[0076] Active ingredients of interest for the skin may have the same activity as the extract according to the invention, or a complementary activity.

[0077] Assets of interest in both the cosmetic and dermatological fields are well known to those in the profession.

[0078] According to a particular embodiment, the cosmetic composition is presented in a form suitable for cutaneous or topical application.

[0079] In the context of this invention, the terms "composition for cutaneous application" or "for topical use" refer to a composition compatible with application to the skin, mucous membranes, hair, and / or scalp, preferably human skin. Thus, and according to a particular embodiment, the composition according to the invention is in a pharmaceutical form suitable for acceptable cosmetic use, that is, compatible with the skin, mucous membranes, hair, and scalp.

[0080] Thus, the composition according to the invention may be in the form of an aqueous, hydroalcoholic, organic, or oily solution; a suspension or dispersion in solvents or fatty substances, such as a lotion or serum; a vesicular dispersion; or an emulsion, in particular water-in-oil (W / O), oil-in-water (O / W), or a combination emulsion such as a water-in-oil-in-water (W / O / W) emulsion. The emulsion may be more or less thick and may be in the form of a cream or lotion. The composition of the invention may also be in the form of an ointment, gel, solid stick, anhydrous paste or solid product, foam, in particular an aerosol, a biphasic composition, or a sprayable composition.

[0081] The composition may be formulated as a solution, aqueous or oily, cream, serum, aqueous gel or oily gel, in particular in a jar or tube, in particular a shower gel, shampoo, milk, emulsion, microemulsion or nanoemulsion, in particular oil-in-water or water-in-oil or multiple or silicone, lotion, in particular in a glass bottle, plastic bottle or dosing bottle or aerosol, ampoule, liquid soap, dermatological bar, ointment, foam, anhydrous product, preferably liquid, paste or solid, for example in stick form, powders.

[0082] According to a particular embodiment, the composition of the invention is in the form of a cream, lotion, solution, emulsion, gel, oil, stick, mousse, powder, spray or mist.

[0083] The galenic form of the composition as well as its method of preparation, and consequently the excipients appropriate to the composition of the invention, can be chosen by a person skilled in the art on the basis of their general knowledge according to the type of composition sought.

[0084] Specifically, the composition may include any fat commonly used in cosmetics. Examples include fats such as oils and waxes of vegetable, mineral, animal, and / or synthetic origin. Oils may be volatile or non-volatile. Other examples include synthetic esters and ethers, fatty alcohols, and fatty acids. The composition may also include an aqueous medium, a hydroalcoholic medium containing an alcohol such as ethanol or isopropanol, or an organic medium comprising common organic solvents such as Cl-6 alcohols, particularly ethanol and isopropanol, glycols such as propylene glycol, and ketones.Naturally, a person skilled in the art will ensure that any additional adjuvants or excipients, and / or their quantity, are chosen in such a way that the advantageous properties of the composition according to the invention are not, or not substantially, altered by the intended addition. The composition may include at least one conventional emulsifier, chosen from amphoteric, anionic, cationic, or nonionic emulsifiers, used alone or in mixtures. It may be particularly advantageous to formulate the composition of the invention so that it is sprayable. This can be achieved, for example, by formulating specific emulsions comprising particular combinations of excipients.

[0085] According to another aspect, the invention relates to the application of an extract as defined above, advantageously of a composition containing it, to the skin, mucous membranes, hair and / or scalp.

[0086] In one embodiment of the invention, the method consists of the topical application of the extract or the composition comprising it to all or part of the human body chosen from among the legs, feet, armpits, hands, thighs, belly, décolleté, neck, arms, torso, back, labial mucosa, face and / or scalp, advantageously the décolleté and / or face, further advantageously the face.

[0087] Another object of the invention relates to the use of the extract or composition according to the invention in various cosmetic and / or dermatological applications, or to prevent and / or treat various conditions described below.

[0088] In other words, the invention also relates to: the extract or composition according to the invention for these different applications; and / or the use of the extract or composition according to the invention to prepare a medicinal product intended to prevent and / or treat these different conditions; and / or

[0089] - a method for preventing and / or treating these different conditions including topical administration of the extract or composition according to the invention.

[0090] Thus, and based on the activities highlighted for the extract according to the invention, the present application covers both cosmetic care processes and therapeutic uses.

[0091] For the purposes of this invention, "cosmetic use and / or cosmetic composition" means a non-pharmaceutical use and / or composition, i.e., one that does not require therapeutic treatment, and is intended for any area of ​​skin, including the scalp, and / or mucous membranes, considered healthy. "Healthy skin and / or mucous membranes" means all or part of an area of ​​skin, including the scalp and / or healthy mucous membranes, particularly human skin, to which the extract according to the invention is applied and which is considered "non-pathological" by a dermatologist, i.e., free from infection, scarring, disease, or skin condition such as candidiasis, impetigo, psoriasis, eczema, acne, or dermatitis, or from wounds or injuries and / or other dermatoses. This therefore refers to the use of the extract on an area of ​​skin and / or mucous membranes of subjects, particularly human subjects, that are considered "normal" by a dermatologist.

[0092] In particular, an extract or composition according to the invention can be used as an antioxidant, healing agent, anti-inflammatory agent, anti-acne agent, or in the treatment of alterations of skin, lip, hair, and / or mucous membrane cells caused by stresses, particularly environmental ones (e.g., pollution).

[0093] In addition, and more specifically related to the field of cosmetics and aesthetics, it can be used as a moisturizing agent, anti-aging agent, soothing agent, barrier function regenerator, or bleaching agent.

[0094] FIGURES

[0095] Figure 1: Test protocols to demonstrate new cosmetic effects of an extract according to the invention

[0096] Figure 2: Results of the transcriptomic study on human keratinocytes

[0097] Figure 3: Results of the transcriptomic study on human fibroblasts

[0098] EXAMPLES OF ACHIEVEMENTS

[0099] The invention and its resulting advantages will become clearer from the following embodiments, supported by the attached figure. These examples, however, are not intended to be exhaustive.

[0100] 1 / Preparation of the active ingredient according to the invention

[0101] 1 / Preparation of yeast extract

[0102] A yeast extract of Saccharomyces cerevisiae was prepared and used at a concentration of between 30g / L and 300g / L.

[0103] 2 / Preparation of the bacterium carrying the glutamate decarboxylase activity

[0104] The bacterium Levilactobacillus brevis was cultured under suitable conditions on an MRS (Man Rogosa, Sharpe) type medium.

[0105] The culture thus obtained is used as is or subjected to freeze-drying for subsequent use in the step of converting glutamic acid to GABA. 3 / Conversion of glutamic acid to GABA

[0106] The conversion is carried out at a temperature between 30 and 40°C and a pH between 5 and 7. Inoculation of the extract with the bacterial culture initiates the conversion. The conversion time is approximately 24 to 70 hours. The reaction is stopped when the conversion to GABA is greater than 90%, ideally complete.

[0107] The resulting GABA-rich extract is then subjected to thermal inactivation and then centrifuged.

[0108] The composition of the final extract obtained, in dry form, is given in the table below:

[0109] Table 1

[0110] II / Demonstration of the impact of the extract according to the invention on the skin

[0111] The effect of a yeast extract such as that obtained in (I), and therefore rich in GABA, was evaluated on different skin cells. These experiments were carried out in parallel on: the same extract but not incubated in the presence of lactic acid bacteria; and commercially available pure synthetic GABA (Ref. A2129, Sigma-Aldrich).

[0112] The experimental setup is illustrated in Figure 1.

[0113] 1 / Tested conditions:

[0114] ■ In vitro cultures of skin cells: adult human primary keratinocytes (principal cells of the epidermis) and human primary fibroblasts (principal cells of the dermis)

[0115] ■ Incubation time: 24 hours

[0116] ■ 4 conditions tested:

[0117] ■ Untreated skin cells

[0118] Skin cells incubated in the presence of the GABA-enriched yeast extract according to the invention

[0119] Skin cells incubated in the presence of yeast extract not enriched with GABA; Skin cells incubated in the presence of commercially purified GABA (at the same concentration in the culture medium as in the presence of the GABA-enriched extract)

[0120] 2 / Tests performed:

[0121] After incubation, the cell samples are used for mRNA recovery, cDNA synthesis, and transcriptomic analysis.

[0122] The correlation between genes whose expression is modulated and possible cosmetic applications is shown in the table below:

[0123] Table 2

[0124] Thus, the modifications observed at the transcriptomic level allow for the allegation of cosmetic indications (anti-aging, regenerating, moisturizing, soothing, protective against oxidative stress...) for an extract according to the invention combining the naturalness, and the presence of GABA, of the various constituents of the yeast extract and of post-biotics, in this case inactivated lactic acid bacteria.

[0125] III / An extract according to the invention. By way of example, three formulations incorporating a yeast extract obtained as described in (I) (referred to as "products of the invention" in the tables below) were prepared. These are cosmetic compositions for topical application, prepared by mixing different parts A, B, C, D, E, or F according to the conventional knowledge of a person skilled in the art.

[0126] Table 3

[0127] Table 4

[0128] Table 5

[0129] IV / Demonstration of the impact of the extract according to the invention on fibroblasts and primary keratinocytes of human skin

[0130] In this in vitro study, normal human epidermal keratinocytes (HEPK) and primary human dermal fibroblasts (HDF) were treated with 3 products:

[0131] Unenriched yeast extract,

[0132] GABA-enriched yeast extract according to the invention, and commercially purified GABA (Sigma-Aldrich).

[0133] After incubation, RNAs were extracted from the cells to study by RT-qPCR 128 genes selected for their importance in epidermal physiology, skin aging, barrier function or oxidative stress, including 3 housekeeping genes used for normalization of results.

[0134] 1 / Materials and methods

[0135] Cell models and incubation with products

[0136] After amplification, adult skin fibroblasts (HDFas, passage 2) and adult skin keratinocytes (HPEKas, passage 3, supplier: CELLnTEC) were seeded at 60,000 cells / well in a 24-well plate (Costar, reference 3526) for 48 hours in ready-to-use CnT Prime Epithelial Proliferation Medium (ref. CnT-PR, CELLnTEC) at 37°C, 5% CO2. For this gene expression study, the cells are in passage 3.

[0137] Next, the cells were incubated with compounds 1 and 3 at 0.1% for 24 hours (Compound 1 = unenriched YE; Compound 3 = YE enriched with GABA according to the invention). Compound 2 (GABA) was used at an equimolar concentration with the GABA-enriched YE to achieve the same final GABA concentration. After 24 hours of incubation with the products, the supernatants were removed and the cell samples were frozen at -80°C.

[0138] RNA extraction

[0139] Total RNA was extracted from each sample using TriPure® Isolation Reagent according to the supplier's instructions.

[0140] RNA quality was assessed by capillary electrophoresis (TapeStation 4200 system, Agilent Technologies). RNA quantity was determined using a spectrophotometer (Synergy HI, Biotek Instruments).

[0141] RT-qPCR

[0142] Complementary DNA (cDNA) was synthesized by reverse transcription of total RNA in the presence of oligo(dT) and Transcriptor Reverse Transcriptase (Roche). The cDNA amounts were adjusted before the quantitative PCR step.

[0143] Quantitative PCR was performed using a LightCycler® system (Roche Molecular Systems Inc.) according to the manufacturer's instructions. The PCR reaction was carried out with a reagent mixture (Ozyme) containing taq DNA polymerase, SYBR Green I, and MgC12 in the presence of specific primers and cDNA.

[0144] Transcript analysis was performed in n=2 using an array PCR targeting 128 genes (125 selected genes + 3 housekeeping genes).

[0145] Gene expression analysis

[0146] The incorporation of fluorescence into the amplified DNA was continuously measured during the PCR cycles. This resulted in a "fluorescence intensity" versus "PCR cycle" graph, allowing the evaluation of a relative expression (RE) value for each marker. The value selected for the RE calculations is the "exit point" (Ct) of the fluorescence curve. For a given marker, the higher the number of cycles, the lower the amount of mRNA. The RE value was calculated using the formula: (1 / 2 number of cycles) x 10⁶.

[0147] The PCR array used in this study included three reference genes (RPS28, GAPDH, and ACTB). These housekeeping genes were used for data normalization because their expression is constitutive and theoretically stable. Therefore, the expression levels of the target markers were compared to the mean expression levels of these three markers across all test conditions.

[0148] The effects were classified according to the relative expression for the "treated" condition versus the "control" condition as shown in the following table:

[0149] The analysis was performed using the 2-AACt method as explained in Livak and Schmittgen 2001.

[0150] DCt = Ct (target gene) - Ct (reference gene)

[0151] DDCt = DCt (target sample) - DCt (reference sample)

[0152] Fold change = 2' DDCt

[0153] 2 / Results on keratinocytes

[0154] The results of the transcriptomic study on human keratinocytes are presented in Figure 2, in which the dotted line at 100% corresponds to the untreated control.

[0155] 2-1 Moisturizing effect, restoration of barrier function, healing or treatment of skin cell alterations caused by environmental stressors

[0156] Genes involved in keratinocyte differentiation

[0157] Incubation with the GABA-enriched yeast extract according to the invention upregulated, compared to the unenriched extract, various genes involved in keratinocyte differentiation:

[0158] IVL encoding the involucrine protein expressed in the upper spinous and granular layers of the epidermis and is recognized as an early marker of epidermal differentiation;

[0159] SPRR1 A and SPRR1B, whose associated proteins act after involucrin for the formation and strengthening of the corneocyte envelope;

[0160] - FLG, which codes for the filaggrin protein, also plays a role in the barrier function. Filaggrin is synthesized as a precursor protein called profilaggrin and is present in keratohyalin granules in the granular layer of the epidermis;

[0161] - Keratin 1 (encoded by KRT1) is expressed in the suprabasal layers of the epidermis and promotes terminal differentiation of keratinocytes;

[0162] - The most overexpressed gene is PADI1 which codes for peptidylarginine deiminase type 1, a calcium-dependent enzyme involved in the later stages of epidermal differentiation and responsible for the deamination of filaggrin and keratin 1.

[0163] SULT2B1 encodes the enzyme sulfotransferase family 2B member 1, which sulfonates various sterols, such as cholesterol, converting them to cholesterol sulfate. The SULT2B1 protein is involved in keratinocyte differentiation and affects the expression of proteins involved in the formation of the stratum corneum, such as loricrin, involucrin, and fdaggrin.

[0164] By promoting the expression of these genes, the GABA-enriched yeast extract according to the invention has benefits for the skin's barrier function (barrier strengthening), and thus helps protect the skin against external aggressors in general (pollution, environmental stress, etc.). In conjunction with the aforementioned benefits for the dermis, it also has a significant impact on skin repair by promoting epidermal differentiation.

[0165] Genes involved in skin hydration

[0166] Furthermore, some of these genes also play a role in skin hydration:

[0167] - Fdaggrin monomers (encoded by the FLG gene, which has been upregulated here) are direct targets of caspase 14 (CASP14) and are cleaved into free and derived amino acids, which act as major contributors to Natural Moisturizing Factor (NMF) that protects the skin against water loss,

[0168] - PADI1, which codes for the calcium-dependent peptidylarginine deiminase protein type 1, is also involved in the formation of NMF.

[0169] 2-2 Restorative effect on barrier function, anti-acne, healing

[0170] Genes involved in innate immunity and the production of antimicrobial peptides

[0171] The yeast extract enriched with GABA according to the invention modulates the expression of genes involved in the production of antimicrobial peptides (AMPs):

[0172] - The proteins of the SPRR superfamily, which play a role in the formation of the stratum corneum, enable the production of antimicrobial proteins (AMPs) to protect the skin barrier, by binding to and disrupting the bacterial membrane.

[0173] CAMP codes for the antimicrobial peptide cathelicidin or LL-37, which can inhibit bacterial biofilm formation by . aureus and S. epidermis and control the growth of C. acnes.

[0174] - PI3 codes for the peptidase 3 inhibitor or elafin which targets Gram-positive and Gram-negative bacteria as well as fungal pathogens.

[0175] Psoriasin, also known as calcium-binding protein S100A7, is encoded by the S100A7 gene and is expressed exclusively by keratinocytes. Psoriasin targets A. coli, C. acnes, and dermatophytes in infected keratinocytes.

[0176] By promoting the expression of these genes, the GABA-enriched yeast extract according to the invention has advantages in strengthening the skin barrier by protecting it from potentially harmful microorganisms (by promoting the skin's natural defenses against external biological aggressions); in protecting the skin against acne; and in the early phases of skin repair since AMPs are involved in the first stages of healing, in conjunction with the effects on the dermis.

[0177] 2-4 Conclusion

[0178] The GABA-enriched extract according to the invention can therefore be used as an agent: moisturizing, barrier function restoration, anti-acne, healing, in the treatment of skin cell alterations caused by environmental stresses.

[0179] 3 / Results on fibroblasts

[0180] The results of the transcriptomic study on human fibroblasts are presented in Figure 3, in which the dotted line at 100% corresponds to the untreated control.

[0181] 3-1 Anti-aging and healing effect

[0182] Genes involved in extracellular matrix components and associated proteins / enzymes

[0183] Incubation with the GABA-enriched yeast extract according to the invention upregulated ELN (elastin) expression by only 37% compared to the untreated control condition, but it increased by 78% compared to the corresponding unenriched extract. This suggests that the GABA-enriched yeast extract according to the invention has a positive impact on skin aging (anti-aging properties).

[0184] Similarly, incubation with the GABA-enriched yeast extract according to the invention upregulated EXTL1 (exostosine-like glycosyltransferase 1) expression compared to the untreated control condition, or to commercial GABA or the corresponding unenriched extract. The encoded protein possesses alpha 1,4-N-acetylglucosaminyltransferase activity and is involved in heparan sulfate chain elongation. Since heparan sulfate is present in perlecan (heparan sulfate proteoglycan 2) and the syndecan family of skin proteoglycans, it impacts the content of the dermal extracellular matrix, its aging, and its repair. This suggests that the GABA-enriched yeast extract according to the invention has a positive impact on skin aging (anti-aging properties) and wound healing (skin repair).

[0185] 3-2 Conclusion

[0186] The GABA-enriched extract according to the invention can therefore be used as an anti-aging and healing agent.

[0187] 4. Conclusion Consequently, the yeast extract enriched with GABA according to the invention can be used in the cosmetic or dermocosmetic field as an anti-aging agent, barrier function restoration agent, moisturizing agent.

[0188] Furthermore, the yeast extract enriched with GABA according to the invention can also be used in the therapeutic field as a healing agent, anti-acne agent, or in the treatment of skin cell alterations caused by stresses, particularly environmental ones.

Claims

DEMANDS 1. Yeast extract containing gamma-aminobutyric acid (GABA), said GABA being obtained from glutamic acid present as a free amino acid in said yeast.

2. Extract according to claim 1, characterized in that it contains at least 5% by weight of GABA, the percentage by weight being expressed in relation to the dry weight of the extract.

3. Extract according to any one of claims 1 to 2, characterized in that it contains less than 10% by weight of glutamic acid, advantageously less than 5%, even more advantageously less than 1%, the percentage by weight being expressed in relation to the dry weight of the extract.

4. Extract according to any one of claims 1 to 3, characterized in that it is a water-soluble extract, advantageously in dry form.

5. Extract according to any one of claims 1 to 4, characterized in that it is obtained from a yeast capable of synthesizing glutamic acid.

6. Extract according to claim 5, characterized in that it is obtained from a yeast of the species Saccharomyces cerevisiae.

7. Extract according to any one of claims 1 to 6, characterized in that the GABA is obtained using the following process: - preparation of yeast extract from yeast containing glutamic acid in the form of a free amino acid; - incubation of the extract in the presence of a glutamate decarboxylase (GAD) enzyme.

8. Extract according to claim 7, characterized in that the glutamate decarboxylase (GAD) enzyme is derived from a bacterium or a lysate of such a bacterium producing said enzyme, advantageously carrying the GadA and / or GadB or even GadC genes.

9. Extract according to claim 8, characterized in that the bacterium belongs to the family of Lactobacillaceae, advantageously selected from the group consisting of: Levilactobacilus brevis, Lentilactobacilus buchneri and Lactococcus lactis, more advantageously in that the bacterium is Levilactobacilus brevis.

10. Extract according to any one of claims 8 to 9, characterized in that the incubation between the bacterium and the yeast extract is carried out under conditions promoting the conversion of glutamic acid to GABA.

11. Extract according to any one of the preceding claims, characterized in that it comprises inactivated bacteria or is free from bacteria.

12. Topical composition comprising an extract according to any one of claims 1 to 11, the extract advantageously representing from 0.01 to 10% by weight of the composition.

13. Composition according to claim 12, characterized in that it is in a form suitable for topical application, advantageously in that it is in the form of a cream, lotion, solution, emulsion, gel, oil, stick, foam, powder, spray or mist.

14. Composition according to claim 12 or 13 for its use as an antioxidant, healing agent, anti-inflammatory agent, anti-acne agent, or in the treatment of alterations of skin, lip, hair, and / or mucous membrane cells caused by environmental stresses.

15. Cosmetic use of a composition according to claim 12 or 13 for the preparation of a cosmetic composition, in particular as a moisturizing agent, anti-aging agent, soothing agent, barrier function restoring agent, or bleaching agent.

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