Silybum marianum (L.) Gaertn. oil in strengthening the skin's barrier function

Abstract

The present invention relates to the cosmetic use of an oil derived from the achenes of Silybum marianum (L.) Gaertn. to prevent a decrease and / or strengthen the epidermal barrier function.

Description

Title of the invention: Silybum marianum (L.) Gaertn. oil in strengthening the skin barrier function. TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to the use of an oil derived from achenes of Silybum marianum (L.) Gaertn. and / or the use of cosmetic compositions comprising such an oil, as well as a cosmetic method for preventing the reduction and / or strengthening the epidermal barrier function. STATE OF THE ART

[0002] The scientific name Silybum marianum (L.) Gaertn. designates a plant belonging to the Asteraceae family, an annual or biennial with a robust stem that can reach over one meter in height. Its large, glossy, alternate leaves, without stipules, are mottled white and edged with hard, sharp spines. The flowers are grouped in terminal heads, often solitary. They are surrounded by large, spiny bracts with very sharp tips. The tubular flowers, with five lobes, are purplish-violet in color. The fruits are glossy achenes, black or mottled yellow, topped with a pappus of ring-shaped, toothed bristles at their base. The main common name for this plant is Milk Thistle. This plant particularly favors dry, sunny locations, often on acidic, dry, and stony soils.Its geographical distribution is concentrated around the Mediterranean, but it is also present in Europe, Western Asia, as well as North America and Australia or even New Zealand. It grows in gardens but is more dominant in uncultivated fields, pastures, along the edges of paths and among rubble.

[0003] The achene (often erroneously referred to as seed in the literature) of Silybum marianum (L.) Gaertn. and its preparations are traditionally used orally in the symptomatic treatment of functional digestive disorders attributed to a hepatic origin.

[0004] The main active principle of the achene of Silybum marianum (L.) Gaertn. is silymarin, which is a mixture of several flavonolignans. Silymarin consists predominantly (at least 95% by weight) of a mixture of the following four flavonolignans: silybin, isosilybin, silychristin, and silydianin (Kuki et al., Chromatographia 2012, 75, 175-180). The achenes contain up to 3% by weight of silymarin. They also consist of oil (15-30% by weight), mucilage, and protein.

[0005] Silymarin has been the subject of numerous studies (in vitro, in vivo and clinical) which have It has demonstrated its antioxidant, hepatoprotective, digestive, and anti-inflammatory properties. Currently, extracts of Silybum marianum (L.) Gaertn. achenes standardized to silymarin content are present in several pharmaceutical preparations intended for the treatment of various liver and biliary disorders, such as Legalon®.

[0006] The antiproliferative effect of silybin was studied in a HepG2 cell model derived from hepatocellular carcinoma. Silybin was shown to induce a significant increase in the synthesis of certain ceramides that can act as second messengers in various apoptotic processes (Zappavigna et al., Int. J. Mol. Sciences 2019, 20, 2190). An increase in ceramide synthesis was also demonstrated in the same cell model by silybins A and B and synthetic derivatives, 3-O-galloyl silybin A and 3-O-galloyl silybin B (Boojar et al., Iranian J. Pharmaceutical Res. 2016, 15(3), 421-433).

[0007] The achenes of Silybum marianum (L.) Gaertn. generally contain 15 to 30% oil. Removing the oil from the achenes (de-oiling) is a prerequisite for silymarin extraction. Silybum marianum (L.) Gaertn. oil is therefore a co-product of silymarin production (Zhu et al., Biochemistry and Pharmacotherapy 2018, 100, 191-197). Silybum marianum (L.) Gaertn. oil is thus devoid of silymarin or contains undetectable traces. This is confirmed by the analysis of the polyphenol fraction of milk thistle oil which does not reveal the presence of any silymarin constituent (Meddeb et al., Antioxidants, 2018, 7, 95; Zarrouk et al., Current Pharmaceutical Design, 2019, 25, 1791-1805).

[0008] Unrefined oil of Silybum marianum (L.) Gaertn. is essentially composed of triglycerides of unsaturated fatty acids, the major components of which are linoleic acid (30 to 60%) and oleic acid (15 to 30%). Its high unsaturated fatty acid content makes it suitable for inclusion in cholesterol-lowering diets and for use in the prevention of cardiovascular diseases (El-Mallah et al., Grasas y Aceites 2003, 54(4), 397-402). The oil also contains saturated fatty acids: palmitic acid (5 to 15%), stearic acid (3 to 8%), arachidic acid (1 to 4%), and behenic acid (1 to 4%). Crude oil obtained by cold pressing also contains phytosterols (beta-sitosterol in particular) and tocopherols (a-tocopherol, and y-tocopherol in particular) (Dabbour et al., Pakistan Journal of Nutrition 2014, 13(2), 67-78).

[0009] Silybum marianum (L.) Gaertn. oil is mainly used in the culinary field.

[0010] Furthermore, studies on the antioxidant and hepatoprotective properties of Silybum marianum (L.) Gaertn. oil, administered orally, have been carried out in vivo on rats or mice (Hermenean et al., Open Life Sci. 2015, 10-225-236; Zhu et al., Pharmacogn Mag 2014, 10(Sup 1), S92-S99).

[0011] Several in tubo or in vitro studies highlight the antioxidant and cytoprotective properties of Silybum marianum (L.) Gaertn. oil obtained by cold pressing or solvent extraction (Dabbour et al., 2014; Harrabi et al., Lipids in Health and Disease 2018, 17, 82; Meddeb et al., Antioxidants 2018 7, 95).

[0012] A clinical study highlights the anti-aging effect on aged skin and with repeated topical application of two cosmetic formulations containing 1% Silybum marianum (L.) Gaertn oil. An improvement in facial wrinkles, dermal density, elasticity, and skin tone is observed after twice-daily applications for two weeks. However, these formulations contain several active ingredients such as palmitoyl peptides, vitamin E, jojoba oil, avocado oil, glycosphingolipids, and sodium hyaluronate (Hahn et al., Experimental and Therapeutic Medicine 2016, 12, 1171-1176).

[0013] The use of Silybum marianum (L.) Gaertn. oil as a biofuel is also considered (Takase et al., Ultrasonics Sonochemistry 2014, 21, 1752-1762).

[0014] The skin is made up of different tissues forming a vital barrier for the body against the external environment. This barrier protects the body against external aggressions, particularly chemical, mechanical or infectious, and as such, a number of defense reactions against environmental factors and / or xenobiotics occur at its level.

[0015] The skin consists of three main parts, a superficial one, the epidermis, an internal part, the dermis and a deeper layer, the hypodermis, which interact.

[0016] The human epidermis is composed of four to five distinct layers (depending on the anatomical site) and four types of cells: keratinocytes (the most numerous), melanocytes, Langerhans cells, and Merkel cells. Each of these cell types contributes, through its specific functions, to the essential role played by the skin in the body, particularly its role in protecting the body from external aggressions. This property is called the barrier function.

[0017] Epidermal cells proliferate in its deepest layer, the basal layer, and differentiate during their migration to the upper layers to successively form the spinous layer, composed of several layers of polyhedral cells arranged on the germinal layers; the granular layer, composed of flattened cells containing distinct cytoplasmic inclusions, the keratohyalin granules; and finally the stratum corneum, which is the outermost layer of the epidermis. The stratum corneum consists of 20 to 30 layers of keratinocytes at the terminal stage of their differentiation, called corneocytes. Corneocytes, the constituent elements of the stratum corneum, are dead, flat cells containing water and keratin. The architecture of the stratum corneum is classically likened to a brick wall. The bricks represent the cor- Neocytes. Keratinocytes are surrounded by a lipophilic "cement" composed of lipids. The barrier function is primarily ensured by the stratum corneum due to its structure and composition. During keratinocyte differentiation, phospholipids, whose role is to build the fluid structure of the cell membranes in the living layers of the epidermis, are gradually replaced by a mixture composed mainly of fatty acids, cholesterol, and sphingolipids (ceramides). These lipids, which are organized into lamellar bilayers, form the intracellular cement of the stratum corneum. The supramolecular organization of inter-keratinocyte lipids plays a crucial role in establishing the physicochemical properties of the stratum corneum and, consequently, in maintaining a physiological water gradient.The structure of these lipid bilayers possesses specific assembly properties, either hexagonal (gelled state) or orthorhombic (a crystalline system whose unit cell is a rectangular parallelepiped), the latter being predominant (Bouwstra et al., Int. J. Cosmet. Sci., 2008, 30, 388). The orthorhombic state represents the densest conformation, and a balance between these two states is necessary for optimal barrier properties. An imbalance in the proportion of the three lipid families in the stratum corneum leads to a modification of the orthorhombic and hexagonal states and, consequently, a modification of the barrier function. This lamellar bilayer structure alternates hydrophilic and lipophilic zones that determine the barrier function, water exchange between the organism and the external environment, and the hydration of the stratum corneum.

[0018] The latter has long been considered a simple layer of dead cells without any real function. In reality, it is metabolically active and largely performs the barrier function of the epidermis.

[0019] The epidermis is not irrigated by any blood vessels and is only supplied by diffusion from the dermis.

[0020] The dermis provides the epidermis with a solid support. The dermis is a connective tissue composed of various cell types, including fibroblasts, lymphocytes, and macrophages. Collagen fibers and elastin, embedded in a gel called the "ground substance," are associated with these cells. Collagen and elastin are synthesized by fibroblasts. Leukocytes, mast cells, and tissue macrophages are also found in the dermis. Finally, blood vessels and nerve fibers, including free sensory fibers and those connected to receptors, permeate the dermis.

[0021] The cohesion between the epidermis and the dermis is ensured by the dermo-epidermal junction. The balance of the skin barrier and mucous membranes depends on complex biological mechanisms involving numerous growth factors, hormones, enzymes and mediators within the epidermis and the dermis.

[0022] Finally, the hypodermis is the deepest and thickest layer of the skin. It is continuous with the dermis, with no real separation between the two tissues. The hypodermis acts as a shock absorber, providing mechanical protection for the underlying structures. This fatty layer also helps insulate the body from temperature variations. While the dermis can be considered a water reservoir, the fats stored within the adipocytes of the hypodermis constitute an energy reserve.

[0023] It is evident that the quality of the skin and mucous membrane barrier is dependent on complex endogenous biological mechanisms involving numerous growth factors, differentiation factors, adhesion molecules, hormones and lipid metabolism enzymes.

[0024] Thus, an alteration of the skin barrier and / or a disruption of the continuity of the skin surface can occur in the presence of external aggressions such as irritants (detergents, acids, bases, oxidants, reducers, concentrated solvents, toxic gases or fumes), mechanical stresses (friction, impacts, abrasion, surface tearing, projection of dust or particles, shaving or waxing), thermal or climatic imbalances (cold, dryness, radiation), or xenobiotics (undesirable microorganisms, allergens), or internal aggressions such as psychological stress. These aggressions cause lipid deficiencies, particularly for ceramides. These changes in lipid ratios will alter the organization of the lipid cement and lead to an alteration of the barrier function, increasing transepidermal water loss and modifying natural hydration factors.These changes will lead to skin dehydration and dryness, and may also worsen cases of atopic dermatitis, and sensations of sensitive or reactive skin.

[0025] This alteration of the skin barrier can manifest itself in particular as skin discomfort, sensory phenomena, and especially unpleasant sensations. This feeling of skin discomfort can be expressed in particular by tingling, tightness, burning, and itching. These sensations of skin discomfort are more frequent in the most exposed areas of the body, namely the hands, feet, face, and scalp. They can occur particularly in areas subjected to certain daily or frequently repeated hygiene practices such as shaving, hair removal, washing with toiletries or household products, the application of adhesives with bandages or patches, the fastening of prostheses, or in the case of sports activities, work-related activities, or simply activities related to lifestyle and the use of clothing, tools, or equipment that generate localized friction.They can also be amplified by psychological stress.

[0026] Alteration of the skin barrier can also promote the appearance of micro-cracks or micro-fissures, particularly on the hands, feet and lips.

[0027] These sensations of skin discomfort affect everyone, and particularly those with sensitive or even intolerant skin. The concept of sensitive skin reflects the level of sensitivity of each individual's skin. While it is possible to have sensitive skin at any age, it is extremely common in babies and the elderly. Babies' skin is about one-fifth the thickness of adult skin. It is therefore extremely sensitive to chemical, physical, and microbial aggressions, as well as to UV rays. The barrier function of adult skin, on the other hand, gradually weakens with age, along with the slowing of metabolic processes. Skin aging gradually leads to a deficiency in lipids, which makes it more easily irritated by alkaline substances such as soap.

[0028] When skin has a very low sensitivity threshold, meaning it reacts excessively to the slightest external aggressor, it is referred to as intolerant skin, or even reactive intolerant skin. Intolerant skin is more vulnerable to external aggressors and is characterized by daily discomfort and significant irritability. Certain signs, more or less pronounced, allow it to be identified. For example, intolerant facial skin presents with redness and tingling, tightness, heat, or itching; it can also cause burning sensations. Intolerant skin generally has an allergic predisposition and is therefore particularly sensitive to the components of cosmetic products.

[0029] Sensitive skin is skin prone to tingling, burning, prickling, and itching, sometimes accompanied by redness. These sensations of discomfort appear in an exacerbated way in reaction to stimuli that would not trigger irritation on so-called normal skin. This hypersensitivity of the skin results from a decrease in its tolerance threshold. The more sensitive the skin, the lower its tolerance threshold, and when the tolerance threshold is at its lowest, it is referred to as intolerant skin. This hypersensitivity can be explained by various factors, but the most important is an alteration of the epidermis' barrier function. This phenomenon then promotes dehydration of the skin and, above all, the penetration of potentially irritating agents.

[0030] The skin is covered by a protective film, called the hydrolipidic film. It constitutes the outermost barrier, as well as the most fragile and the most easily disrupted. It is largely composed of fatty substances secreted by the sebaceous glands and lipids resulting from cell breakdown (squalene, waxes, triglycerides, free fatty acids, cholesterol esters) during the keratinization of the stratum corneum, as well as hydrophilic compounds, such as sweat water, glycerol, urea, and other factors. The skin's natural hydrating agents, salts, and metabolites of the skin flora are essential. This surface film is highly exposed and very sensitive to environmental stressors, hygiene habits, skin condition, and exposure to UV radiation. The microbiota can significantly alter sebum composition, break down triglycerides, and modify free fatty acid ratios, particularly during periods of stress or illness. It is therefore crucial to preserve and even enhance this skin barrier function, especially for the most sensitive skin.

[0031] There is always a need for agents to prevent a decrease in and / or strengthen the skin barrier function. Summary of the invention

[0032] Surprisingly and unexpectedly, the inventors have shown that the oil from achenes of Silybum marianum (L.) Gaertn. induces a cutaneous synthesis of lipids, in particular an endogenous synthesis of ceramides which allows, in addition to the nourishing and / or moisturizing effect for the skin, the strengthening of the epidermal barrier function or the prevention of a decrease in this epidermal barrier function, but also the strengthening of the protection of the skin against water loss and / or external aggressions.

[0033] According to a first aspect, the invention relates to the cosmetic use of an oil derived from the achenes of Silybum marianum (L.) Gaertn. to prevent a decrease and / or strengthen the epidermal barrier function.

[0034] According to a second aspect, the invention relates to the cosmetic use of a cosmetic composition comprising at least one oil derived from achenes of Silybum marianum (L.) Gaertn. with at least one cosmetically acceptable excipient, to prevent a decrease and / or strengthen the epidermal barrier function.

[0035] According to a third aspect, the invention relates to a cosmetic method for preventing a decrease and / or strengthening the epidermal barrier function, comprising administering to a person in need an effective amount of an oil derived from achenes of Silybum marianum (L.) Gaertn. or of a cosmetic composition comprising at least an oil derived from achenes of Silybum marianum (L.) Gaertn. with at least one cosmetically acceptable excipient.

[0036] Definitions

[0037] In the present invention, the plant Silybum marianum (L.) Gaertn. may be referred to in abbreviated form as Silybum marianum.

[0038] For the purposes of this invention, "organic solvent immiscible with oil from Silybum marianum achenes" means an organic solvent that is not capable of mixing, or only partially mixing, with oil from Silybum marianum achenes, such that the mixture of the organic solvent and the oil from achenes of Silybum marianum give a heterogeneous mixture in which at least two distinct phases can be observed.

[0039] For the purposes of this invention, "nonpolar solvent" means a solvent selected, for example, from heptane, hexane, limonene, halogenated hydrocarbons (e.g., C1 to C3 chlorinated hydrocarbons such as chloroform or dichloromethane), supercritical CO2, a mixture of supercritical CO2 and ethanol, and mixtures of these solvents. Also included are 100% bio-based solvents such as EcoXtract LIPOCOS (supplier Pennakem Europa).

[0040] For the purposes of this invention, "refining" refers to the steps of deodorizing and / or bleaching and / or desolvating Silybum marianum oil. Crude oils contain a number of constituents responsible for unpleasant tastes and odors and poor shelf life, which may therefore be desirable to remove.

[0041] For the purposes of this invention, "deodorization" means a treatment aimed at eliminating the odor or taste of a vegetable oil. Deodorization can be carried out by heating the oil to a high temperature (e.g., between 150 and 300°C, in particular between 150 and 250°C or between 150 and 200°C), under vacuum, with the injection of steam.

[0042] For the purposes of this invention, "bleaching" refers to a treatment designed to reduce the color of vegetable oil. The color can be measured according to the Gardner scale. The Gardner color scale is a visual comparison scale for the color of clear and transparent liquids. Bleaching can be achieved by contacting the oil with a bleaching earth (which absorbs the pigments (e.g., carotene, chlorophyll, etc.) responsible for the color) and heating it (e.g., between 60 and 100°C), which can be done under vacuum. Advantageously, a subsequent filtration step separates the oil from the now-used bleaching earth.

[0043] For the purposes of this invention, "desolventization" means a treatment that removes the solvent present in an oil. Desolventization can be carried out by distillation by heating the mixture under vacuum and / or by steam distillation under vacuum.

[0044] For the purposes of this invention, "C1 to C3 alcohol" means an R-OH alcohol whose R chain is a saturated, linear or branched hydrocarbon chain comprising 1 to 3 carbon atoms. This may be methanol, ethanol, n-propanol, or isopropanol, particularly methanol, ethanol, or isopropanol. Preferably, it will be isopropanol.

[0045] For the purposes of this invention, "ambient temperature" means a temperature between 15 and 40°C, preferably between 20 and 30°C, in particular approximately 25°C.

[0046] In this description, "approximately" means that the value in question may be 10% lower or higher, in particular 5%, in particular 2%, more particularly 1%, than the value indicated.

[0047] For the purposes of this invention, "topical application" means application to the skin (including the scalp) and mucous membranes.

[0048] For the purposes of this invention, "epidermal barrier" means the cellular structures of the epidermis, in particular the tissue barrier formed by the comeocytes and the intercellular lipid cement.

[0049] By "epidermal barrier function", we mean, in the context of the present invention, the protective function of the epidermis, in particular against external aggressions, and the regulation of insensible water loss and ions.

[0050] For the purposes of this invention, "cosmetically acceptable" means something that is useful in the preparation of a cosmetic composition, that is generally safe, non-toxic and neither biologically nor otherwise undesirable, and that is acceptable for cosmetic use, in particular by topical application to the skin. DETAILED DESCRIPTION OF THE INVENTION

[0051] According to a first aspect, the invention relates to the cosmetic use of an oil derived from the achenes of Silybum marianum (L.) Gaertn. to prevent a decrease and / or strengthen the epidermal barrier function.

[0052] According to a particular embodiment, the invention relates to the cosmetic use of an oil derived from the achenes of Silybum marianum (L.) Gaertn to strengthen the protection of the skin against water loss and / or external aggressions.

[0053] According to a particular embodiment, the invention relates to the cosmetic use of at least one oil derived from the achenes of Silybum marianum (L.) Gaertn to nourish and / or moisturize the skin, including the scalp, and / or mucous membranes.

[0054] According to a particular embodiment, the invention relates to the cosmetic use of at least one oil derived from achenes of Silybum marianum (L.) Gaertn to improve skin repair, by strengthening or restoring the barrier function.

[0055] According to a particular embodiment, the invention relates to the cosmetic use of at least one oil derived from the achenes of Silybum marianum (L.) Gaertn to prevent and / or reduce tingling, itching, tightness, redness, and skin irritation.

[0056] The oil from Silybum marianum achenes will be used more particularly topically, in particular by application to the skin.

[0057] In the context of the present invention, the oil obtained from the achenes of Silybum marianum is obtained from the fruit (achene), the achenes being either whole or in pieces.

[0058] In the context of the present invention, the oil from Silybum marianum achenes can be obtained by pressing the achenes or by extracting the achenes with a nonpolar solvent.

[0059] In one embodiment of the present invention, the oil from Silybum marianum achenes can be obtained by pressing Silybum marianum achenes, in particular by cold pressing, i.e. without heating, at room temperature, followed by a filtration step.

[0060] In a particular embodiment of the invention, the oil from Silybum marianum achenes is obtained by pressing the Silybum marianum achenes, followed by a filtration step and then refining.

[0061] In a particular embodiment of the invention, the oil from Silybum marianum achenes is obtained by pressing the Silybum marianum achenes, followed by a filtration step, then an extraction step with a polar to medium-polar extraction solvent to remove the polar compounds from the oil, the polar to medium-polar extraction solvent comprising, in particular, a hydrotropic aqueous solution, subcritical water or an organic solvent not miscible with the oil from Silybum marianum achenes optionally mixed with water, then optionally a desolvating step.

[0062] Advantageously, the polar to medium-polar extraction solvent comprises, in particular, an oil-immiscible organic solvent derived from Silybum marianum achenes, optionally mixed with water.

[0063] The oil-immiscible organic solvent derived from Silybum marianum achenes may be, in particular, a C3 Ci alcohol.

[0064] The polar to medium polar extraction solvent may be, in particular, a C3 Ci alcohol possibly mixed with water.

[0065] The oil-immiscible organic solvent from Silybum marianum achenes, in particular a C1 to C3 alcohol such as methanol, ethanol or isopropanol, may be used in a mixture with water, in particular in an organic solvent / water volume ratio of between 80 / 20 and 100 / 0, in particular between 85 / 15 and 95 / 5, in particular about 90 / 10.

[0066] The polar to medium polar extraction solvent may in particular be chosen from methanol, a methanol / water mixture, ethanol, an ethanol / water mixture, isopropanol and an isopropanol / water mixture.

[0067] According to a preferred embodiment, the polar to medium-polar extraction solvent will be methanol, an ethanol / water mixture in a volume ratio of about 90 / 10 or an isopropanol / water mixture in a volume ratio of about 90 / 10, preferably an isopropanol / water mixture in a volume ratio approximately 90 / 10.

[0068] The extraction step using a polar to medium-polar extraction solvent for the oil from Silybum marianum achenes will be carried out in particular by mixing the oil from Silybum marianum achenes with the polar to medium-polar extraction solvent for 1 to 12 hours, and in particular at a temperature between 15 and 25°C, especially around 20°C. The quantity of polar to medium-polar extraction solvent used to carry out this extraction will advantageously be from 0.5 to 3 g, in particular from 1 to 3 g per 1 g of oil from Silybum marianum achenes.

[0069] An extraction phase and a lipid phase (residual oil devoid of its polar compounds, also called exhausted residual oil) will be obtained at the end of this extraction. The lipid phase will advantageously be separated from the extraction phase and recovered. It can then be desolventized, particularly under vacuum, to remove the residual polar to moderately polar extraction solvent and obtain an oil from Silybum marianum achenes that is devoid of its polar constituents (free fatty acids, phytosterols, tocopherols).

[0070] In a particular embodiment of the invention, the oil from Silybum marianum achenes is obtained by pressing the Silybum marianum achenes, then extraction with a polar to medium-polar extraction solvent to remove polar compounds from the oil as detailed above, then desolvating as previously described, then deodorizing.

[0071] In a particular embodiment of the invention, the oil from Silybum marianum achenes is obtained by pressing the Silybum marianum achenes, then extraction with a polar to medium-polar extraction solvent to remove polar compounds from the oil as detailed above, then desolvating as previously described, then bleaching.

[0072] In a particular embodiment of the invention, the oil from Silybum marianum achenes is obtained by pressing the Silybum marianum achenes, then extraction with a polar to medium-polar extraction solvent to remove polar compounds from the oil as detailed above, then desolventization as previously described, then deodorization and / or bleaching.

[0073] According to a second aspect, the invention relates to the use of a cosmetic composition comprising at least one oil derived from Silybum marianum achenes with at least one cosmetically acceptable excipient, to prevent a decrease and / or strengthen the epidermal barrier function.

[0074] According to a particular embodiment, the invention relates to the use of a cosmetic composition comprising at least one oil derived from Silybum marianum achenes with at least one cosmetically acceptable excipient, to enhance the protection of the skin against water loss and / or external aggressions.

[0075] According to a particular embodiment, the invention relates to the use of a cosmetic composition comprising at least one oil derived from Silybum marianum achenes with at least one cosmetically acceptable excipient, to nourish and / or moisturize the skin, including the scalp, and / or mucous membranes.

[0076] According to a particular embodiment, the invention relates to the use of a cosmetic composition comprising at least one oil derived from Silybum marianum achenes with at least one cosmetically acceptable excipient, to improve skin repair, by strengthening or restoring the barrier function.

[0077] According to a particular embodiment, the invention relates to the use of a cosmetic composition comprising at least one oil derived from Silybum marianum achenes with at least one cosmetically acceptable excipient, to prevent and / or reduce tingling, itching, tightness, redness, and skin irritation.

[0078] Advantageously the oil from Silybum marianum achenes included in the cosmetic composition is prepared as described above.

[0079] In a particular embodiment, the cosmetic composition according to the invention comprises between 0.01 and 40% by weight relative to the total weight of the composition, in particular between 0.1 and 20% by weight, in particular between 0.1 and 10% by weight, more particularly between 0.1 and 5% by weight, even more particularly between 0.1 and 2% by weight, and even more particularly between 0.5 and 1% by weight of oil from Silybum marianum achenes relative to the total weight of the composition.

[0080] Preferably, the oil from Silybum marianum achenes is present in the cosmetic composition at a content of approximately 1% by weight relative to the total weight of the composition.

[0081] The cosmetic compositions according to the invention are advantageously intended for topical application, in particular by application to the skin.

[0082] The cosmetic compositions according to the invention may thus be presented in the forms which are usually known for topical administration, that is to say in particular lotions, milks, emulsions, serums, balms, masks, creams, dispersions, gels, foams or sprays.

[0083] Advantageously it will be a balm and / or a lotion.

[0084] The invention thus relates to cosmetic compositions according to one of the embodiments of the present invention, characterized in that they are presented in a form suitable for topical application.

[0085] The cosmetic compositions according to the invention, in addition to the oil derived from Silybum marianum achenes and a physiologically acceptable medium, may also contain surfactants, complexing agents, preservatives, and other agents. stabilizers, emulsifiers, thickeners, gelling agents, humectants, emollients, trace elements, essential oils, perfumes, colorants, mattifying agents, chemical or mineral filters, moisturizing agents, thermal waters, etc.

[0086] According to a third aspect, the invention relates to a cosmetic method for preventing a decrease and / or strengthening the epidermal barrier function, comprising administering, in particular topically, for example by application to the skin, to a person in need of an effective amount of an oil derived from Silybum marianum achenes or of a cosmetic composition comprising at least one oil derived from Silybum marianum achenes with at least one cosmetically acceptable excipient.

[0087] According to a particular embodiment, the invention relates to a cosmetic method for strengthening the protection of the skin against water loss and / or external aggressions, comprising administering, in particular topically, for example by application to the skin, to a person in need of an effective quantity of an oil derived from Silybum marianum achenes or of a cosmetic composition comprising at least one oil derived from Silybum marianum achenes with at least one cosmetically acceptable excipient.

[0088] According to a particular embodiment, the invention relates to a cosmetic method for nourishing and / or moisturizing the skin, including the scalp, and / or mucous membranes, comprising administering, in particular topically, for example by application to the skin, to a person in need of an effective amount of an oil derived from Silybum marianum achenes or of a cosmetic composition comprising at least one oil derived from Silybum marianum achenes with at least one cosmetically acceptable excipient.

[0089] According to a particular embodiment, the invention relates to a cosmetic method for improving skin repair, by strengthening or restoring the barrier function, comprising administering, in particular topically, by application to the skin, to a person in need, an effective amount of an oil derived from Silybum marianum achenes or of a cosmetic composition comprising at least one oil derived from Silybum marianum achenes with at least one cosmetically acceptable excipient.

[0090] According to a particular embodiment, the invention relates to a cosmetic method for preventing and / or reducing tingling, itching, tightness, redness, and skin irritation, comprising administering, particularly topically, by application to the skin, to a person in need, an effective amount of an oil derived from the achenes of Silybum marianum or of a cosmetic composition comprising at least one oil derived from the achenes of Silybum marianum with at least one cosmetically acceptable excipient.

[0091] Advantageously the oil from Silybum marianum achenes is prepared as described above and the cosmetic composition is as described above.

[0092] The following examples illustrate the invention without limiting its scope. EXAMPLES

[0093] Example 1: Preparation of oil from Silybum marianum achenes obtained by cold pressing

[0094] Cold pressing of Silybum marianum achenes then filtration on filter press to obtain a first pressing crude oil from Silybum marianum (L.) Gaertn. achenes.

[0095] Example 2: Preparation of oil from Silybum marianum achenes, deprived of its polar compounds and refined

[0096] This process is carried out in 8 steps:

[0097] - Cold pressing of Silybum marianum achenes followed by filtration on a filter press for to obtain a first pressing crude oil from achenes of Silybum marianum (L.) Gaertn.

[0098] - Extraction of first-press crude oil from Silybum marianum achenes by an isopropanol / water mixture (90 / 10 v / v) with 1 weight of the isopropanol / water mixture to 1 weight of oil for 10 hours at 20°C

[0099] - Recovery of the lipid phase (depleted residual oil)

[0100] - Desolventization of exhausted residual oil: removal of the solvent by evaporation vacuum distillation followed by steam distillation under the following conditions: Step 1 - Distillation: Distillation temperature: 90°C Distillation time: 2 hours Vacuum: 2 mbar progressive Step 2 - stripping: Steam: approximately 7 kg / h Stripping temperature: 90°C Stripping duration: 1 hour Vacuum: 2-20 mbar

[0101] - Decolorization of exhausted and desolventized residual oil under the conditions following: Natural bleaching earth: Tonsil® 210 FF Decolorization temperature: 80°C Bleaching time: 45 minutes Vacuum: 10-20 mbar

[0102] - Filtration on filter press

[0103] - Deodorization under the following conditions: Deodorization temperature: 180°C Deodorization time: 2 hours Stripping: steam (approx. 7 kg / h) Vacuum: 2-20 mbar

[0104] - Filtration on cartridge filter.

[0105] Example 3: Effects of oils from Silybum marianum achenes on the synthesis of total lipids and ceramides in a reconstructed epidermis model

[0106] The primary function of the epidermis is to protect the body by forming a vital protective barrier against external aggressions and the risk of dehydration. The stratum corneum, the outermost layer of the skin, is largely responsible for this barrier function. This stratum corneum consists of corneocytes embedded in a lipid matrix, the highly specific organization of which depends on its lipid composition. This composition includes free fatty acids, cholesterol, and ceramides. The lipids form multiple layers superimposed on one another. In vitro experiments have demonstrated that the specific lipid composition of the stratum corneum alone enables this particular arrangement of lipids into lamellar bilayers (De Jager et al., J. Lipid res. 2005, 46, 2649-2656). These lipids play a key role in the skin's barrier function.

[0107] Ceramides constitute a lipid family of great biological importance because they enable the cohesion of the stratum corneum and, consequently, the formation of the skin barrier. Biochemically, they are sphingolipids resulting from the amidation of sphingosine with a fatty acid. They can be free or covalently bound to stratum corneum proteins. Currently, 14 classes of ceramides have been identified and are named according to their chemical structure: ceramides can have a sphingosine (S), dihydrosphingosine (dS), phytosphingosine (P), or 6-hydroxysphingosine (H) base to which is linked a ω-hydroxy (EO or O), α-hydroxy (A), or non-hydroxy (N) fatty acid with an alkyl chain of variable length.EO ceramides have a unique structure because they possess a very long γ-hydroxy acid chain of more than 34 carbon atoms linked to a linoleic acid and will play a predominant role in the organization of the lamellar bilayers of the stratum corneum and consequently on the barrier function.

[0108] The quantification of ceramides provides information on the integrity or lack of the barrier function and provides a valuation of dermo-cosmetic products.

[0109] A wide variety of ceramides make up the lipid composition of the stratum corneum. They alone represent approximately half of the intercellular lipids. Ceramides play a key role in the organization of the lamellar bilayers and In particular, ultra-long-chain esterified ceramides such as EOS, EOP, and EOH ceramides (Bouwstra et al., Biochim Biophys Acta 1996, 1300(3), 177-186). The importance of esterified ceramides, due to their very long carbon chains, has been demonstrated in relation to lamellar repeat distance and chain arrangement (Kessner et al., Chem Phys Lipids, 2010, 163(1), 42-50). Furthermore, the polar heads of ceramides, especially CER EOS and CER EOP, exert a considerable influence on the structural properties required for a functional lipid matrix.

[0110] Non-esterified ceramides are predominant and are important not only for barrier function but also for skin hydration and nutrition. Studies have shown that, during winter, dry skin conditions have been correlated with a decrease in total ceramide levels, and more specifically with NP and NH ceramide levels (Ishikawa et al., J. Cosmet Dermatol 2013, 12(1), 3-11). In patients with atopic dermatitis, a significant decrease in total ceramide levels has also been reported, particularly with NP, NS, and NH ceramide levels, and an inverse correlation with transepidermal water loss, indicating impaired barrier function (Ishikawa et al., J Invest Dermatol, 2010, 130(10), 2511-2514).

[0111] The decrease in ultra-long-chain esterified ceramides, as well as the shortening of the chain lengths of free fatty acids and ceramides in general, leads to a change in lipid organization towards a less dense state (Kessner et al., Skin Pharmacol Physiol 2008, 21(2), 58-74). This creates spaces in the lipid arrangement between corneocytes, leading to a reduction in skin barrier function and increased skin permeability. Thus, an increase in these specific lipids induces an improvement in skin barrier function.

[0112] The aim of this study is to evaluate the impact of oil from Silybum marianum achenes on the synthesis of cutaneous lipids, and in particular on the synthesis of ceramides, major constituents of the stratum corneum, from a lipid perspective, and to assess the nutritional effect for treatment and improvement of barrier function. Ceramides, free fatty acids, and cholesterol from the stratum corneum are analyzed by high-performance thin-layer chromatography (HPTLC). This rapid technique is widely used to separate complex mixtures such as lipids (Fuchs et al., J. Chromatography A 2011, 1218(19), 2754-2774), and the method used has been the subject of a scientific publication (Jamin et al., Eur J Mass Spectrum, 2019, 25(3), 278-290). The oil effect is evaluated on 3 batches of reconstructed epidermis with n=3 (triplicate) per experimental condition and per batch.After treatment with oil from achenes of . Silybummarianum, the lipids of the stratum comeum are quantified by HPTLC in order to assess the impact of the treatment on the synthesis of cutaneous lipids.

[0113] Method

[0114] The model used in this study is a reconstructed epidermis model derived from skin excisions from cosmetic surgery according to the method described by Frankart et al. (Frankart et al., Exp. Dermatol. 2012, 21(11), 871-875).

[0115] The cells (keratinocytes) are isolated from the skin excisions, then cultured before being seeded onto culture inserts immersed in culture medium, then the culture inserts are placed at the air / liquid interface in an incubator at 37°C in a humidified atmosphere with 5% CO2, to form the stratum comeum.

[0116] It takes 14 days to regenerate a reconstructed epidermis with a surface area of ​​0.6cm2. The culture medium is changed every 24 hours.

[0117] Three reconstructed epidermis are used per condition (control, oil from Silybum marianum achenes obtained by cold pressing, and positive control).

[0118] Control: Tween® 20 at 0.01% in phosphate buffer pH 7.4 (PBS);

[0119] Oil derived from the achenes of Silybum marianum: - 1st series of experimentation: oil obtained according to example 1, tested at 1% in Tween® 20 at 0.01% in phosphate buffer pH 7.4 (PBS); - 2nd series of experimentation: oil obtained according to example 2, tested at 1% in Tween® 20 at 0.01% in phosphate buffer pH 7.4 (PBS);

[0120] Positive control: Dexeryl® cream.

[0121] On day 9 of the protocol, the compounds to be tested are applied for the first time to the reconstructed epidermis (2 mg for Dexeryl® cream, 5 µl of oil from Silybum marianum achenes obtained by cold pressing at 1% in Tween® 20 / PBS or 5 µl of Tween® 20 / PBS for the epithelium control). A 24-hour incubation is carried out.

[0122] A second application (same conditions) is carried out on the 10th day, with an incubation of 48 hours.

[0123] A third application (same conditions) is carried out on the 13th day, with 24 hours of incubation.

[0124] Finally a fourth application (same conditions) is carried out on the 14th day (epithelium completely reconstructed), with 24 hours of incubation.

[0125] On day 15, the reconstructed epidermis is removed from the culture inserts, and the stratum corneum is isolated from the rest of the epidermis using trypsin. The stratum corneum is then extracted using organic solvents (a mixture of chloroform and methanol) to collect its constituent lipids. These lipids are then concentrated under liquid nitrogen before HPLC analysis.

[0126] Ceramides, free fatty acids, and cholesterol from the stratum comeum are analyzed by HPTLC. The analytical conditions are detailed below, particularly in Table 1.

[0127] Plate: Lichrospher® HPTLC Silica gel 60 F254S Deposit: 6 mm wide, dried under nitrogen flow Development: gradient: see Table 1 Post-derivatization: aqueous copper sulfate solution (10% CuSO4, 8% H3PO4, 5% MeOH) Detection: X scanner: 450 nm.

[0128] [Tables] Steps Chloroform Acetone MeOH / Water / Acetic Acid (97 / 3 / 1 v / v / v) Distance (mm) 1 81.5 4 14.5 20 2 81.7 4 14.3 30 3 82 4 14 42 4 83 4 13 46 5 84.5 4 11.5 54 6 85 4 11 57 7 86 4 10 59 8 87 4 9 67 9 88 4 8 75 10 90 5 5 83 11 100 0 0 90

[0129] Results

[0130] It is known that Dexeryl® cream increases lipid synthesis. Therefore, Dexeryl® cream was chosen as a positive control and was applied to the reconstructed epithelia at 2 mg / epithelium.

[0131] Several classes of lipids are analyzed by HPTLC, free fatty acids, cholesterol derivatives (cholesterol oleate and cholesterol sulfate) and ceramides.

[0132] 1 ^series of experiments

[0133] In this first series of experiments, the positive control (Dexeryl® cream) induced, as expected, lipid synthesis, associated with an increase in Free fatty acids, cholesterol derivatives, and ceramides were detected. These results validate the experimental conditions.

[0134] The oil derived from Silybum marianum achenes according to Example 1 has no effect on the synthesis of free fatty acids and induces a slight decrease in total cholesterol (-4.3%), but this reduction does not reach statistical significance. On the other hand, the oil derived from Silybum marianum achenes according to Example 1 significantly increases the synthesis of total ceramides (+36.1%). This result allows us to conclude that this oil derived from Silybum marianum achenes demonstrates a significant nourishing effect on the skin.

[0135] Ceramides are present as the dominant lipids in the stratum corneum and play a crucial role in the skin barrier function, thereby limiting dehydration and water retention. Based on the important properties of ceramides, the focus was placed on different subclasses of ceramides produced by the application of silybum marianum oil. Since these ceramides were not present in the formulation, the ceramides found in the stratum corneum correspond solely to ceramides produced by the skin.

[0136] Table 2 below shows the percentage induction of ceramides produced after application of oil from Silybum marianum achenes according to example 1 compared to the control.

[0137] [Tables2] CER AH CER AP CER NH CER AS and EOH CER AdS and OH CER NP CER EOP CER NdS and NS CER EOS 15.3% 24.4% 25.8% 39.0% 45.3% 44.3% 63.7% 46.4% 32.0% P<0.01 P<0.05 P<0.05 P<0.05 P<0.01 P<0.05 P<0.01 P<0.001 P<0.05

[0138] Thus, oil from Silybum marianum achenes, compared to untreated reconstructed epidermis (control), induces a statistically significant synthesis of all ceramides in this reconstructed epidermis model. It is interesting to note that the increase in the synthesis of the ceramide CER EOS exceeds 30%, this ceramide being present in reduced quantities in cases of eczema and atopic dermatitis, and playing an important role in the barrier function and, in particular, the organization of lamellar bilayers. Furthermore, the ceramides involved in the lamellar organization of lipids in the stratum corneum, i.e., the ultra-long-chain esterified ceramides, such as EOS, EOH, and EOP ceramides, are significantly increased by at least 30%. The non-esterified ceramides are Also increased are ceramides NP and NS, which are the major ceramides in the stratum corneum. Ceramide NP is the major ceramide and contributes 8–13% to the total ceramides (Van Smeden et al., J Lipid Res 2011, 52(6), 1211–1221). This ceramide plays an important role in the formation of lamellar bilayers with ultra-long-chain esterified ceramides, as well as ceramide AdS, which is also induced by the topical application of oil from Silybum marianum achenes (Bouwstra et al., Biochim Biophys Acta 1996, 1300(3), 177–186). Ceramide NP along with ceramide NH are also implicated in dry skin when the amounts of these ceramides decrease (Ishikawa et al., J Cosmet Dermatol 2013, 12(1), 3-11).Increasing the level of total ceramides, and in particular ceramides that are major players in the barrier function such as EOS, NP and NS ceramides, through the application of oil derived from Silybum marianum achenes, is very favorable for a strengthening effect on the epidermal barrier function.

[0139] 2 Qd-^experimental series

[0140] In this second series of experiments, the positive control (Dexeryl® cream) induced, as expected, lipid synthesis, particularly of cholesterol derivatives and total ceramides. It should be noted that lipid synthesis was lower than that observed in the first series of experiments. These results nevertheless validate the experimental conditions.

[0141] Under these conditions, the oil derived from Silybum marianum achenes according to Example 2 increases the synthesis of total ceramides by approximately 13.6% compared to untreated reconstructed epidermis. These results therefore demonstrate a nourishing effect of this oil.

[0142] As in the first series of experiments, the study focused on different classes of ceramides necessarily induced by the application of the products to the skin, since ceramides are absent from the formulations. The results obtained by applying the oil derived from Silybum marianum achenes according to Example 2 are summarized in Table 3.

[0143] Table 3 below shows the percentage induction of ceramides produced by the application of oil from Silybum marianum achenes according to example 2.

[0144] [Tables3] CER AH CER NH CER AdS and OH CER NP CER EOP CER NdS and NS CER EOS 5.9 25.8 30.5 12.7 12.8 20.7 25.7 NSS P<0.05 P<0.01 P<0.05 P<0.05 P<0.05 P<0.05

[0145] The oil from Silybum marianum achenes according to example 2 induces a statistically significant production of almost all ceramides, in particular ceramides which are major players in the barrier function.

[0146] All these results demonstrate that the oil from Silybum marianum achenes has a nourishing effect but is also capable of inducing an endogenous synthesis of ceramides and thus improving the epidermal barrier function.

Claims

Demands

1. Oil from the achenes of Silybum marianum (L.) Gaertn. for its use in preventing a decrease and / or strengthening the epidermal barrier function.

2. Oil for its use according to claim 1, to enhance the protection of the skin against water loss and / or external aggressions.

3. Oil for its use according to claim 1, to nourish and / or moisturize the skin, including the scalp and / or mucous membranes.

4. Oil for its use according to claim 1, to improve skin repair, by strengthening or restoring the barrier function.

5. Oil for its use according to claim 1, to prevent and / or reduce tingling, itching, tightness, redness or irritation of the skin.

6. Oil for its use according to any one of claims 1 to 5, characterized in that it is obtained by a process comprising a cold pressing step of the achenes of Silybum marianum (L.) Gaertn., followed by a filtration step.

7. Oil for its use according to claim 6, characterized in that the filtration step is followed by an extraction step with a polar to medium-polar extraction solvent to give an extraction phase and a lipid phase, separation of the extraction phase and the lipid phase, and recovery of the lipid phase.

8. Oil for its use according to claim 7, characterized in that the polar to medium polar extraction solvent is a Cl to C3 alcohol.

9. Oil for its use according to any one of claims 7 and 8, characterized in that the recovered lipid phase is then desolventized, and optionally deodorized and / or bleached.

10. Cosmetic composition comprising at least one oil derived from Silybum marianum (L.) Gaertn. achenes with at least one cosmetically acceptable excipient, for its use in preventing a decrease and / or strengthening the epidermal barrier function.

11. Cosmetic composition for its use according to claim 10, to strengthen the protection of the skin against water loss and / or external aggressions.

12. Cosmetic composition for use according to claim 10, to nourish and / or moisturize the skin, including the scalp and / or mucous membranes.

13. Cosmetic composition for use according to claim 10, to improve skin repair by strengthening or restoring the barrier function.

14. Cosmetic composition for use according to claim 10, to prevent and / or reduce tingling, itching, tightness, redness, or skin irritation.

15. Cosmetic composition for use according to any one of claims 10 to 14, characterized in that it contains from 0.1 to 2% by weight of oil from achenes of Silybum marianum (L.) Gaertn. relative to the total weight of the composition.