Himanthalia elongata extract, cosmetic composition comprising same, and uses thereof

Abstract

The invention relates to an extract of brown algae of the species Himanthalia Elongata having a content greater than or equal to 100 mg / kg of sulfoquinovosyldiacylglycerol (SQDG) dissolved in 1,3-propanediol, to the use thereof as an active cosmetic substance for preventing, alleviating or treating the unaesthetic signs of skin ptosis, to a cosmetic composition comprising said extract, and to a cosmetic treatment method for human skin for preventing, alleviating or treating the unaesthetic signs of skin ptosis.

Description

[0001] WHIMANTHALIA ELONGATA EXTRACT, COSMETIC COMPOSITION COMPRISING IT, AND ITS USES

[0002] The present invention relates to an extract of brown algae of the species Himanthalia Elongata comprising sulfoquinovosyldiacylglycerol (SQDG) dissolved in a cosmetically acceptable solvent, its use as a cosmetic active ingredient for preventing, reducing or treating the unsightly signs of skin sagging, a cosmetic composition comprising said extract as well as a method for cosmetic treatment of human skin aimed at preventing, reducing or treating the unsightly signs of skin sagging.

[0003] The skin is composed of three layers, in order from the outer surface: the epidermis, the dermis, and the hypodermis. The epidermis is primarily composed of keratinocytes. The dermo-epidermal junction, also called the basement membrane, is an acellular zone between the dermis and the epidermis. It is composed of lamina lucida, lamina densa, and a fibrillar zone. It serves as cohesion between the dermis and the epidermis. The dermis is a dense, fibroelastic connective tissue, the production and eventual remodeling of which are primarily carried out by fibroblasts. It is made up of the extracellular matrix (ECM) composed of fibrous molecules such as collagen and elastin. The dermo-hypodermal junction, located at the interface between the dermis and the hypodermis, is composed of alternating dermal and hypodermal extrusions. It represents an important place of exchange between the fibroblasts of the dermis and the adipocytes of the hypodermis.The hypodermis is the deepest and thickest layer of human skin and contains adipocytes, connective tissue, nerves, blood vessels and macrophages.

[0004] Clinical signs of the face are the basis of how others perceive us, including their perception of our age. Signs of skin aging can be classified into four broad categories: wrinkles / texture, lack of firmness of skin tissue (ptosis), vascular disorders, and pigmentary heterogeneities (1).

[0005] Wrinkles, like ptosis (sagging skin), are therefore changes in the skin linked to skin aging but are distinguished histologically and clinically.

[0006] Histological analysis of wrinkles shows that the epidermis and superficial dermis are modified (2). In particular, a decrease in the quality of keratinocyte differentiation, the thickness of the epidermis and dermis, and the quantity of elastin and collagens is observed (3): the micro-relief is modified, the skin becomes hollow, and the wrinkle appears.

[0007] Unlike the appearance of wrinkles, two theories have been proposed to explain the phenomenon of skin sagging. The first involves gravity, and the second associates volumetric changes in the face. It manifests clinically as facial sagging, a worsening of the nasolabial fold, for example, and a loss of skin firmness. These changes are correlated with a loss or reduction in its biomechanical properties.

[0008] The biomechanical properties of the skin describe its behavior when subjected to one or more mechanical constraints such as gravity, friction, rubbing, or even facial expressions induced by subcutaneous muscles. Young skin is capable of stretching reversibly in response to a mechanical stimulus. It adapts and returns to its initial state: the skin is elastic. With age, it loses its biomechanical properties of elasticity and is irreversibly subjected to mechanical constraints: the signs of aging appear, and the skin sags.

[0009] At the biological level, several modes of action can explain these age-related mechanical modifications: i) the weakening of the dermo-epidermal junction

[0010] The dermoepidermal junction is structured to provide support and integrity to the skin. Over time, it thins partly due to a reduction in the expression level of collagen IV and collagen XVII (4)(5)(6).

[0011] Collagen IV is a structural collagen located in the lamina densa, which acts as a cohesion between the epidermis and the dermis. Collagen XVII is a transmembrane protein located at the dermo-epidermal junction, allowing strong anchoring of keratinocytes in the basement membrane through its interaction with collagen IV (7). Their reduction over time is responsible for the sagging of human skin and its loss of elasticity (8). ii) the decrease in collagen composition in the dermis

[0012] The architecture and composition of the dermis are also responsible for the mechanical properties of human skin. Fibroblasts synthesize extracellular matrix proteins such as type I collagen, which forms a strong fibrous network providing strength, firmness, and elasticity to the skin (3)(9). With age, it becomes scarce and the skin becomes loose (3)(9). iii) the decrease in mechanobiology

[0013] Mechanobiology or mechanotransduction studies how cells respond to mechanical stimuli exerted by their environment. The skin is constantly subjected to mechanical stress. When a force is applied, the fibroblast, the majority constituent of the dermis, is able to sense the mechanical stimuli thanks to the transmembrane mechanoreceptor integrin pi located at the interface with the extracellular matrix, and to transmit it until it causes cellular adaptation (10)(l 1). Stress fibers composed of α-SM actin, for example, are able to respond to strong tension and induce contraction of the fibroblasts (12)(13). Thanks to this mechanotransduction process, young, firm skin is able to stretch and return to its initial state easily. However, with age, the skin loses its ability to perceive, transmit, and adapt to mechanical stress: it becomes less firm and slackens (14).iv) reduction of the rigidity of the dermo-hypodermal junction.

[0014] Skin sagging is not only related to the superficial layers of the skin. Although the hypodermis has often been considered an inert tissue only responsible for fat storage, numerous scientific evidences suggest its importance in anti-aging strategies (15). Indeed, fibroblasts located at the junction between the dermis and the hypodermis have a specific biological signature related to the mechanical support of the dermis (16). In addition, the hypodermis close to the dermis is more rigid suggesting its role in the mechanical properties of the skin and therefore in skin sagging (17).

[0015] Himanthalia elongata is a species of brown seaweed in the family Himanthaliaceae, order Fucales. Its common name is "sea bean" or "sea spaghetti" and it is edible, with a sweet and salty taste. Recent studies have shown that Himanthalia elongata has excellent antimicrobial and antioxidant properties (18).

[0016] The international application published under number WO 2005 / 4972 A1 describes a whitening, anti-wrinkle and anti-oxidant cosmetic composition containing a mixed extract of algae including sea spaghetti Himanthalia elongata). In its preparation, each algae is extracted separately and then mixed with the others. The extraction is carried out with water alone or in a mixture with alcohols which promotes the extraction of polysaccharides and polar compounds.

[0017] US patent application published under number US 2020 / 197296 A1 describes the use of compositions which are mixtures of several algae extracts including the aqueous extract of Himanthalia Elongata to improve skin firmness and elasticity.

[0018] The international application published under number WO 96 / 25142 A1 concerns the use of galactolipids, in particular galactosylglycerides, especially digalactosyldiglycerides (DGDG), and extracts of natural origin containing these products, in the field of cosmetics more specifically and in general, to strengthen the biomechanical properties of the dermis, to improve the surface appearance of the skin, or to prevent or treat the effects of skin aging, such as wrinkles or sagging of skin support tissues. Galactosylglycerides can be obtained by synthesis, or by extraction from animal tissues, in particular the brain, the spinal cord or from plants, in particular cereals such as wheat or oats, or an extract of Ginkgo Biloba leaves or nuts.

[0019] The French patent application published under number FR 3082430 A1 describes the use of a fucosterol or one of its derivatives or a cosmetic composition containing it from algae of the Phaeophyceae class including Himanthalia Elongata to prevent / treat skin sagging or remodeling of skin tissue, maintaining or stimulating the contractile forces of fibroblasts. The extraction of fucosterol is carried out using solvents such as vegetable oils and esterified oils to obtain a liposoluble extract containing fucosterol.

[0020] The international application published under number WO 2021 / 255003 A1 describes the use of a ^Himanthalia Elongata extract or composition containing it as a lightening and anti-aging agent. The extraction is carried out with water alone at a pH of approximately 2, which promotes the exclusive extraction of polar compounds (polysaccharides, minerals, proteins, polar polyphenols) which are hydrolyzed.

[0021] As part of their research into new cosmetic active ingredients with excellent efficacy in preventing and / or treating the effects of sagging skin, the inventors set out to develop a new technical solution consisting of a new extract of brown algae from the species Himanthalia Elongata enriched with polar lipids, in particular sulfoquinovosyldiacylglycerol (SQDG), with the aim of preventing or visibly reducing sagging skin, a particular characteristic of aging.

[0022] The present invention thus relates to an extract of brown algae of the species Himanthalia Elongata comprising a content greater than or equal to 100 mg / kg of sulfoquinovosyldiacylglycerol (SQDG) dissolved in a cosmetically acceptable solvent, 1,3-propanediol.

[0023] The expression "cosmetically acceptable" used in the definition of cosmetic formulation for topical use means, according to the European Economic Community Council Directive No. 76 / 768 / EEC of 27 July 1976, amended by Directive No. 93 / 35 / EEC of 14 June 1993, that the said formulation includes any substance or preparation intended to be placed in contact with the various parts of the human body (epidermis, hair and capillary system, nails, lips and genitals) or with the teeth and oral mucous membranes with a view, exclusively and mainly, to cleaning them, perfuming them, modifying their appearance and / or correcting body odours and / or protecting them or maintaining them in good condition.

[0024] Said extract of brown algae of the species Himanthalia Elongata comprising a content greater than or equal to 100 mg / kg, preferably greater than or equal to 110 mg / kg, of sulfoquinovosyldiacylglycerol (SQDG) dissolved in 1,3-propanediol. is obtained: either by the process comprising the following successive steps:

[0025] A step a) of providing a ground brown algae of the Himanthalia Elongata species,

[0026] A step b) of extracting the sulfoquinovosyldiacylglycerol (SQDG), the chlorophyll and optionally the triglycerides present in said ground brown algae made available in step a), by mixing the latter with a first solvent SI of alcoholic and / or apolar type, to obtain a first liquid phase comprising said solvent SI, the residual ground brown algae not dissolved in said solvent SI and the sulfoquinovosyldiacylglycerol (SQDG), the chlorophyll, and optionally the triglycerides dissolved in said solvent SI,

[0027] A step c) of separation by filtration, from said first liquid phase obtained at the end of step b), of said residual brown algae ground material not dissolved in said solvent SI, to obtain a second liquid phase comprising said solvent SI, sulfoquinovosyldiacylglycerol (SQDG), chlorophyll, and optionally the triglycerides dissolved in said solvent SI,

[0028] Optionally, a step d) of concentrating said second liquid phase obtained at the end of step c), by evaporation, at least partially, of said first solvent SI, to obtain a second concentrated liquid phase comprising said solvent SI, sulfoquinovosyldiacylglycerol (SQDG), chlorophyll, and optionally the triglycerides dissolved in said solvent SI,

[0029] A step e) of mixing said second liquid phase obtained at the end of step c) or said second concentrated liquid obtained at the end of step d), with 1,3-propanediol, to obtain a third liquid phase comprising a mixture of said solvents SI and 1,3-propanediol, sulfoquinovosyldiacylglycerol (SQDG), chlorophyll and optionally triglycerides,

[0030] A step f) of removing by evaporation the first solvent SI from said third liquid phase obtained in step e), to obtain a fourth liquid phase comprising 1,3-propanediol, chlorophyll and optionally the triglycerides not dissolved in 1,3-propanediol and sulfoquinovosyldiacylglycerol (SQDG) dissolved in 1,3-propanediol, and

[0031] A step g) of separation by filtration, from said fourth liquid phase obtained in step f), of the chlorophyll and optionally of the triglycerides not dissolved in the 1,3-propanediol, to obtain said expected brown algae extract; or by the process comprising the following successive steps:

[0032] A step h) of providing a ground brown algae of the Himanthalia Elongata species,

[0033] A step i) of extracting the sulfoquinovosyldiacylglycerol (SQDG), the chlorophyll and optionally the triglycerides present in said ground brown algae made available in step h), by mixing the latter with a first SI solvent of alcoholic and / or apolar type and 1,3-propanediol, to obtain a fifth liquid phase comprising the SI solvents and the 1,3-propanediol, the residual ground brown algae, the sulfoquinovosyldiacylglycerol (SQDG), the chlorophyll and optionally the triglycerides,

[0034] A step j) of removing by evaporation said first solvent SI present in said fifth liquid phase obtained in step i), to obtain a sixth liquid phase comprising 1,3-propanediol, said residual brown algae ground material, chlorophyll and optionally triglycerides not dissolved in 1,3-propanediol and sulfoquinovosyldiacylglycerol (SQDG) dissolved in 1,3-propanediol, and

[0035] A step k) of separation by filtration, from said sixth liquid phase obtained in step j), of said residual brown algae ground material, of the chlorophyll and optionally of the triglycerides not dissolved in 1,3-propanediol, to obtain said expected brown algae extract.

[0036] In another alternative embodiment of the variant of the method according to the invention as defined above, said steps j) and k) can be replaced by the following steps:

[0037] - A step 1) of separation by filtration, from said fifth liquid phase obtained in step i), of said residual brown algae ground material, to obtain a sixth liquid phase comprising the solvents SI and 1,3-propanediol, sulfoquinovosyl-diacylglycerol (SQDG), chlorophyll and optionally triglycerides,

[0038] - A step m) of elimination by evaporation of said first solvent SI present in said sixth liquid phase obtained in step 1), to obtain a seventh liquid phase comprising 1,3-propanediol, chlorophyll and optionally triglycerides not dissolved in 1,3-propanediol and sulfoquinovosyldiacylglycerol (SQDG) dissolved in 1,3-propanediol, and

[0039] - A step n) of separation by filtration, from said seventh liquid phase obtained in step m), of the chlorophyll and optionally of the triglycerides not dissolved in 1,3-propanediol, to obtain said expected brown algae extract. Said ground brown algae of the species Himanthalia Elongata made available in step a) or h) is preferably obtained from a harvest of whole brown algae of the species Himanthalia Elongata which is then dried, ground, and if necessary sieved to obtain a powder of the desired average diameter.

[0040] According to a particular aspect of the invention, step b) is carried out by macerating said ground material in a first SI solvent of alcoholic and / or apolar type to prepare a mixture of said ground material of brown algae of the species Himanthalia Elongata with a first SI solvent of alcoholic and / or apolar type, then by stirring this mixture under conditions effective for extracting chlorophyll, polar lipids, in particular sulfoquinovosyldiacylglycerol (SQDG), and optionally triglycerides present in said ground material. The effective conditions are known to those skilled in the art depending on the specific SI solvent chosen.

[0041] The first alcoholic solvent SI used in the method and in its variant according to the invention is an alcohol or an aqueous solution comprising an alcohol. Said alcohol is advantageously chosen from ethanol, isopropanol, methanol or a mixture of two or more of these alcohols. The volume ratio of alcohol to water in said aqueous solution may be between 50% and 99%, more particularly between 60% and 96%.

[0042] According to a preferred aspect of the method and its variant according to the invention, the first solvent SI is 96% ethanol in water. Step b) is for example carried out with 96% ethanol in water as the first solvent SI at a temperature of 35°C to 45°C for approximately 30 minutes to 3 hours.

[0043] According to a particular aspect of the invention, step b) is carried out by passing a first non-polar type SI solvent continuously through said ground brown algae of the species Himanthalia Elongata under conditions effective for extracting chlorophyll, polar lipids, in particular sulfoquinovosyldiacylglycerol (SQDG) and possibly triglycerides present in said ground material. The effective conditions are known to those skilled in the art depending on the specific SI solvent chosen.

[0044] The first non-polar type SI solvent used in the process and its variant according to the invention is advantageously chosen from hexane, cyclohexane, methyl tetrahydrofuran, benzene, supercritical carbon dioxide or a mixture of at least two of these solvents. According to a preferred aspect of the process and its variant as defined above, the first SI solvent is supercritical carbon dioxide. Step b) of the process according to the invention is carried out under conditions known to those skilled in the art. For example, step b) is carried out with supercritical carbon dioxide as the first SI solvent at a pressure of 20 MPa to 60 MPa (200 to 600 bars) and at a temperature of 35°C to 50°C with a flow rate of 5 to 15 kg / h for approximately 60 minutes to 4 hours.

[0045] The first solvent SI used in the process and its variant according to the invention may be supercritical carbon dioxide with an alcoholic type co-solvent (an alcohol or an aqueous solution comprising an alcohol), the alcohol being chosen from ethanol, isopropanol, methanol or a mixture of two or more of these alcohols.

[0046] The first solvent SI used in the variant of the process according to the invention may be supercritical carbon dioxide with 1,3-propanediol, (in step i)).

[0047] The first solvent SI promotes the extraction of chlorophyll, sulfoquinovosyldiacylglycerol (SQDG) and possibly triglycerides present in said ground brown algae of the species Himanthalia Elongata and makes it possible to solubilize chlorophyll, sulfoquinovosyldiacylglycerol (SQDG) and possibly said triglycerides.

[0048] The term "residual brown algae ground material" means the fibrous materials of the brown algae of the species Himanthalia Elongata remaining after the extraction of chlorophyll, sulfoquinovosyldiacylglycerol (SQDG) and possibly said triglycerides in step b) of the process or in step i) of the variant of the process according to the invention.

[0049] The first liquid phase obtained in step b) may be in the form of a suspension in which the particles of the residual brown algae ground material are insoluble and dispersed in the solvent SI in which said sulfoquinovosyldiacylglycerol (SQDG), the chlorophyll and possibly the triglycerides are soluble.

[0050] The first liquid phase obtained in step b) may be in the form of a heterogeneous mixture in which the residual brown algae ground material is sedimented in the solvent SI in which said sulfoquinovosyldiacylglycerol (SQDG), chlorophyll and possibly triglycerides are soluble.

[0051] At the end of this extraction step, the first liquid phase thus obtained is then filtered using, for example, a stainless steel basket to remove the residual brown algae ground material and obtain a second liquid phase comprising said solvent SI in which said sulfoquinovosyldiacylglycerol (SQDG), chlorophyll and possibly triglycerides are soluble (step c).

[0052] According to an advantageous variant of the invention, the second liquid phase obtained in step c) is concentrated to remove at least part of the solvent S 1. For example, said solvent S1 is evaporated by means of, for example, a vacuum evaporator to reduce the volume of said second liquid phase. This concentration step makes it possible to limit the size of the reactors used.

[0053] Said second aqueous phase or said second concentrated aqueous phase obtained at the end of step c) or step d) is then mixed with 1,3-propanediol (step e). The addition of 1,3-propanediol to said second aqueous phase or said second concentrated aqueous phase (or the mixing of 1,3-propanediol with said second liquid phase or said second concentrated liquid phase) makes the chlorophyll and possibly triglycerides extracted from the ground brown algae of the species Himanthalia Elongata insoluble. A third liquid phase is then obtained comprising a mixture of said SI solvents and 1,3-propanediol in which sulfoquinovosyldiacylglycerol (SQDG) is soluble and the chlorophyll and possibly triglycerides extracted from the ground brown algae of the species Himanthalia Elongata are insoluble.

[0054] The quantity of SI solvent used is determined by the quantity of ground brown algae of the species Himanthalia Elongata to be extracted made available in step a) or in step h) and the quantity of 1,3-propanediol is determined by the desired final dry extract mass content in the extract obtained. For example, for 50 kg of ground brown algae of the species Himanthalia Elongata, a quantity of 600 kg of SI solvent and 150 kg of 1,3-propanediol are used to achieve an extract whose dry extract is 2%.

[0055] According to a preferred aspect of the process of its variant as defined above, said first solvent SI is 96% ethanol in water.

[0056] According to an advantageous variant of the invention, step b) of extraction with the solvent SI and step e) of mixing with 1,3-propanediol are carried out in a single step (step i).

[0057] The extraction of polar lipids, chlorophyll and possibly triglycerides present in said ground brown algae of the species Himanthalia Elongata in step i) is advantageously carried out by bringing the solvents SI and 1,3-propanediol into contact simultaneously or successively with said ground brown algae of the species Himanthalia Elongata made available in step h) or by bringing into contact a mixture of the solvents SI and 1,3-propanediol previously prepared. Advantageously, said first solvent SI is 96% ethanol.

[0058] Mixing, for example by maceration and stirring, said ground brown algae of the species Himanthalia Elongata with the solvents SI and 1,3-propanediol, in particular with a mixture of the solvents SI and 1,3-propanediol, makes it possible to extract the sulfoquinovosyl diacylglycerol (SQDG), the chlorophyll and possibly the triglycerides present in said ground brown algae of the species Himanthalia Elongata and to render the chlorophyll and possibly the triglycerides insoluble in the solvents SI and 1,3-propanediol or in said mixture of solvents SI and 1,3-propanediol while solubilizing the sulfoquinovosyldiacylglycerol (SQDG). A fifth liquid phase is then obtained comprising said SI solvents and 1,3-propanediol in which sulfoquinovosyldiacylglycerol (SQDG) is soluble and the residual brown algae ground material, chlorophyll and possibly triglycerides extracted from the brown algae ground material of the species Himanthalia Elongata are insoluble.

[0059] In a first advantageous alternative, the fifth liquid phase obtained in step i) then undergoes the elimination of said first solvent SI by evaporation, advantageously until the total evaporation of the solvent SI, to obtain a sixth liquid phase comprising 1,3-propanediol, in which the sulfoquinovosyldiacylglycerol (SQDG) is soluble and the residual brown algae ground material, the chlorophyll and possibly triglycerides extracted from the brown algae ground material of the species Himanthalia Elongata are insoluble (step j).

[0060] In a second advantageous alternative, the fifth liquid phase obtained in step i) then undergoes separation by filtration of said residual brown algae ground material, to obtain a sixth liquid phase comprising the solvents SI and 1,3-propanediol, sulfoquinovosyldiacylglycerol (SQDG), chlorophyll and optionally triglycerides (step 1). The sixth liquid phase obtained in step 1) then undergoes removal of said first solvent S 1 by evaporation, advantageously until the total evaporation of the solvent SI, to obtain a seventh liquid phase comprising 1,3-propanediol, in which the sulfoquinovosyldiacylglycerol (SQDG) is soluble and the chlorophyll and optionally triglycerides extracted from brown algae ground material are insoluble (step m).

[0061] In the same way, the third liquid phase obtained in step e) of the process undergoes the elimination of said first solvent SI by evaporation, advantageously until the total evaporation of the solvent SI to obtain a fourth liquid phase comprising 1,3-propanediol, in which sulfoquinovosyldiacylglycerol (SQDG) is soluble and chlorophyll and optionally triglycerides extracted from the ground brown algae of the species Himanthalia Elongata are insoluble (step f).

[0062] In the process and its variant according to the invention, the removal of the solvent SI promotes the precipitation of chlorophyll and possibly triglycerides insoluble in 1,3-propanediol. The polarity of 1,3-propanediol is important in order to precipitate chlorophyll and possibly triglycerides, and to solubilize sulfoquinovosyl diacylglycerol (SQDG). Advantageously, the boiling point of the solvent SI is lower than that of 1,3-propanediol.

[0063] Following step g), k) or n) of separation by filtration of the insoluble or precipitated matter, an extract of brown algae of the species Himanthalia Elongata comprising a content greater than or equal to 100 mg / kg, in particular greater than or equal to 110 mg / kg, of sulfoquinovosyldiacylglycerol (SQDG) dissolved in 1,3-propanediol is obtained.

[0064] The brown algae extract of the species Himanthalia Elongata thus obtained advantageously contains neither chlorophyll nor triglycerides.

[0065] According to a preferred aspect of the invention, said extract of brown algae of the species Himanthalia Elongata comprises a content greater than or equal to 110 mg / kg of sulfoquinovosyldiacylglycerol (SQDG) dissolved in 1,3-propanediol.

[0066] According to a preferred aspect of the invention, the parameter a* according to the CIELAB color space of said extract of brown algae of the species Himanthalia Elongata is greater than or equal to -5.

[0067] In the international colorimetric system, the parameters of the L*a*b* system express the following characteristics: the lightness L* which takes values ​​between 0 (black) and 100 (reference white); the parameter a* represents the value on a green-red axis; the parameter b* represents the value on a blue-yellow axis.

[0068] The a* parameter is commonly used in the field of colorimetry (CIE system) to measure the value of the color on an axis from green to red. Indeed, the a* parameter describes the position between the opposing colors green and red. If a* < 0 the color tends towards green and if a* > 0 the color tends towards red. When a* > -5 the green coloration linked to chlorophyll is not distinguishable to the naked eye.

[0069] According to a preferred aspect of the invention, the mass content of dry matter (dry extract) of said extract of brown algae of the species Himanthalia Elongata is greater than or equal to 1%, in particular greater than or equal to 1.5%, more particularly greater than or equal to 1.7%, even more particularly greater than or equal to 2%.

[0070] The present invention also relates to the use of an extract of brown algae of the species Himanthalia Elongata as defined above, as a cosmetic active ingredient for preventing or reducing (attenuating or treating) the signs of aging, in particular the unsightly signs of sagging skin, and in particular as an anti-sagging skin agent, in particular in a cosmetic composition for topical use.According to a particular aspect of the invention, said extract of brown algae of the species Himanthalia Elongata is intended to prevent or reduce the unsightly signs of skin sagging by one or more of the following effects: stimulation of the expression of collagen IV and / or collagen XVII, stimulation of the expression of integrin pi and / or α-SM actin, stimulation of the traction force exerted by the fibroblast on its extracellular matrix, increase in the rigidity of the dermis-hypodermis interface, and increase in the density and / or content of collagen at the dermis-hypodermis interface.

[0071] For the purposes of the present invention, the term "anti-sagging agent" means a chemical substance or a chemical composition or an extract derived from the biomass of a plant whose property or technical function consists of preventing or reducing (alleviating or treating) sagging of the skin or of improving the firmness of the skin.

[0072] The terms "skin sagging", "skin sagging" or "sagging of human skin" or "the unsightly signs of skin sagging" are used interchangeably within the meaning of the present invention and mean a loss or reduction of its biomechanical properties, such as for example facial sagging and loss of skin firmness, or also for example the worsening of the nasolabial fold.

[0073] The present invention also relates to a cosmetic composition for topical use comprising a cosmetically effective amount of an extract of brown algae of the species Himanthalia Elongata as defined above, and at least one cosmetically acceptable excipient / medium / ingredient.

[0074] The expression "for topical use" used in the definition of the cosmetic composition which is the subject of the present invention means that said composition is formulated to allow its application to the skin, hair, scalp, nails, lips, mucous membranes, eyelashes, eyebrows, whether it is a direct application or an indirect application when said composition is integrated for example in the case of a body care product in the form of a textile or paper wipe or sanitary products intended to be in contact with the skin, hair, scalp, nails, lips, mucous membranes, eyelashes, eyebrows.

[0075] By effective quantity of the extract of brown algae of the species Himanthalia Elongata, is meant for 100% by mass of said composition, the concentration by weight of between 0.1% by mass and 10% by mass, more particularly between 0.1% and 5% by mass, and even more particularly between 0.5% and 2% by mass of said extract.

[0076] According to a preferred aspect of the invention, the cosmetic composition which is the subject of the present invention comprises for 100% of its mass:

[0077] - from 0.05% to 5% by mass of the brown algae extract of the species Himanthalia Elongata as defined above, and

[0078] - from 95% to 99.95% by mass of at least one cosmetically acceptable ingredient.

[0079] In particular, the cosmetic composition which is the subject of the present invention comprises for 100% of its mass:

[0080] - 2% by mass of the brown algae extract of the species Himanthalia Elongata as defined above, and

[0081] - 98% by mass of at least one cosmetically acceptable ingredient.

[0082] The composition according to the invention is in particular intended to prevent or reduce (attenuate or treat) sagging of the skin or to improve the firmness of the skin.

[0083] The cosmetic composition which is the subject of the present invention, present in the form of an aqueous or hydro-alcoholic or hydro-glycolic solution, in the form of a suspension, an emulsion, a microemulsion or a nano-emulsion, whether of the water-in-oil, oil-in-water, water-in-oil-in-water or oil-in-water-in-oil type, or in the form of a powder.

[0084] The cosmetic composition which is the subject of the present invention may be packaged in a bottle, in a pump-type "bottle" device, an aerosol device in pressurized form, in a device equipped with an openwork wall such as a grid or in a device equipped with a ball applicator (or also called "roll-on").

[0085] In the context of the invention, the cosmetically acceptable ingredient is a chemical and / or biological additive usually used in the field of formulations for topical use.

[0086] In general, the brown algae extract of the species Himanthalia Elongata which is the subject of the present invention may be combined with chemical and / or biological additives usually used in the field of formulations for topical use, such as foaming and / or detergent surfactants, thickening and / or gelling surfactants, thickening and / or gelling agents, stabilizing agents, film-forming compounds, solvents and co-solvents, hydrotropic agents, thermal or mineral waters, plasticizing agents, emulsifying and co-emulsifying agents, opacifying agents, pearlescent agents, superfatting agents, sequestering agents, chelating agents, oils, waxes, antioxidants, perfumes, essential oils, preservatives, conditioning agents, deodorant agents, bleaching agents intended for bleaching hair and skin,active ingredients intended to provide a treatment and / or protective action on the skin or hair, sun filters, mineral fillers or pigments, particles providing a visual effect or intended for the encapsulation of active ingredients, exfoliating particles, texturizing agents, optical brighteners, insect repellents, probiotics.,

[0087] Examples of foaming and / or detergent surfactants that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, include anionic, cationic, amphoteric or non-ionic foaming and / or detergent surfactants.

[0088] Among the foaming and / or detergent anionic surfactants which can be combined with the brown algae extract in the cosmetic composition, object of the present invention as defined above, mention may be made of the salts of alkali metals, alkaline earth metals, ammonium, amines, or amino alcohols of alkyl ether sulfates, alkyl sulfates, alkylamido ether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates, alpha-olefin sulfonates, paraffin sulfonates, alkyl phosphates, alkyl ether phosphates, alkyl sulfonates, alkylamide sulfonates, alkylaryl sulfonates, alkyl carboxylates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylamide sulfosuccinates, alkyl sulfoacetates, alkyl sarcosinates, acyl isethionates, N-acyl taurates, acyl lactylates, N-acyl derivatives of amino acids, N-acyl derivatives of peptides, N-acyl derivatives of proteins, N-acyl derivatives of fatty acids.

[0089] Among the foaming and / or detergent amphoteric surfactants, mention may be made of alkylbetaines, alkylamidobetaines, sultaines, alkylamidoalkylsulfobetaines, imidazoline derivatives, phosphobetaines, amphopolyacetates and amphopropionates.

[0090] Among the foaming and / or detergent cationic surfactants which can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, mention may be made in particular of quaternary ammonium derivatives.

[0091] Among the foaming and / or detergent non-ionic surfactants which can be combined with the brown algae extract in the cosmetic composition, object of the present invention as defined above, mention may be made more particularly of alkylpolyglycosides comprising a linear or branched, saturated or unsaturated aliphatic radical, and comprising from 8 to 16 carbon atoms, such as octyl polyglucoside, decyl polyglucoside, undecylenyl polyglucoside, dodecyl polyglucoside, tetradecyl polyglucoside, hexadecyl polyglucoside, 1-12 dodecanediyl polyglucoside; ethoxylated hydrogenated castor oil derivatives such as the product marketed under the INCI name “Peg-40 hydrogenated castor oil”; polysorbates such as Polysorbate 20, Polysorbate 40, Polysorbate 60, Polysorbate 70, Polysorbate 80, Polysorbate 85; coconut amides; N-alkylamines.

[0092] Examples of thickening and / or gelling surfactants that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention as defined above, include optionally alkoxylated alkylpolyglycoside fatty esters, such as ethoxylated methylpolyglucoside esters such as PEG 120 methyl glucose trioleate and PEG 120 methyl glucose dioleate marketed respectively under the names GLUCAMATE™ LT and GLUMATE™ DOE120; alkoxylated fatty esters such as PEG 150 pentaerythritol tetrastearate marketed under the name CROTHIX™ DS53, PEG 55 propylene glycol oleate marketed under the name ANTIL™ 141; fatty chain polyalkylene glycol carbamates such as PPG-14 laureth isophoryl dicarbamate marketed under the name ELFACOS™ T211, PPG-14 palmeth-60 hexyl dicarbamate marketed under the name ELFACOS™ GT2125.

[0093] Examples of thickening and / or gelling agents that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention as defined above, include polyelectrolyte type polymers, linear or branched or crosslinked, such as the homopolymer of partially or totally salified acrylic acid, the homopolymer of partially or totally salified methacrylic acid, the homopolymer of partially or totally salified 2-methyl-[(l-oxo-2-propenyl)amino]-l-propanesulfonic acid (AMPS), the copolymers of acrylic acid and AMPS, the copolymers of acrylamide and AMPS, the copolymers of vinylpyrrolidone and AMPS, the copolymers of AMPS and (2-hydroxyethyl)acrylate, the copolymers of AMPS and (2-hydroxyethyl) methacrylate, copolymers of AMPS and hydroxyethylacrylamide, copolymers of AMPS and N,N-dimethyl acrylamide,copolymers of AMPS and tris(hydroxy-methyljacrylamido methane (THAM), copolymers of acrylic or methacrylic acid and (2-hydroxyethyl)acrylate, copolymers of acrylic or methacrylic acid and (2-hydroxyethyl)methacrylate, copolymers of acrylic or methacrylic acid and hydroxyethylacrylamide, copolymers of acrylic or methacrylic acid and THAM, copolymers of acrylic or methacrylic acid and N,N-dimethylacrylamide, terpolymers of acrylic or methacrylic acid, AMPS and (2-hydroxyethyl)acrylate, terpolymers of acrylic or methacrylic acid, AMPS and (2-hydroxyethyl)methacrylate, terpolymers of acrylic or methacrylic acid, AMPS and THAM, terpolymers of acrylic or methacrylic acid, AMPS and N,N-dimethyl acrylamide, terpolymers of acrylic or methacrylic acid, AMPS and acrylamide,copolymers of acrylic acid or methacrylic acid and alkyl acrylates whose carbon chain comprises between four and thirty carbon atoms and more particularly between ten and thirty carbon atoms, copolymers of AMPS and alkyl acrylates whose carbon chain comprises between four and thirty carbon atoms and more particularly between ten and thirty carbon atoms, linear, branched or crosslinked terpolymers of at least one monomer having a strong acid function, free, partially salified or totally salified, with at least one neutral monomer, and at least one monomer of formula (XIII): CH2=C(R'3)-C(=O)-[CH2-CH2-O]n'-R'4 (XIII) in which R'3 represents a hydrogen atom or a methyl radical, R'4 represents a linear or branched alkyl radical comprising from eight to thirty carbon atoms and n' represents a number greater than or equal to to one and less than or equal to fifty.,

[0094] The polyelectrolyte type polymers, linear or branched or crosslinked, which can be associated with the brown algae extract in the cosmetic composition, object of the present invention as defined above, can be in the form of a solution, an aqueous suspension, a water-in-oil emulsion, an oil-in-water emulsion, a powder. The polyelectrolyte type polymers, linear or branched or crosslinked, which can be associated with the hydro-alcoholic extract from a biomass of aerial parts of a plant of the Plumbaginaceae family in the composition (Ci), can be selected from the products marketed under the names SIMULGEL™ EG, SIMULGEL™EPG, SEPIGEL™ 305, SIMULGEL™ 600, SIMULGEL™ NS, SIMULGEL™ INS 100, SIMULGEL™ FL, SIMULGEL™ A, SIMULGEL™ SMS 88, SEPINOV™EMT 10, SEPIPLUS™400, SEPIPLUS™265, SEPIPLUS™S, SEPIMAX™Zen, SEPILIFE™ NUDE, ARISTOFLEX™AVC, ARISTOFLEX™AVS, ARISTOFLEX™AVL, ARISTOFLEX™BLV, ARISTOFLEX™Silk,

[0095] ARISTOFLEX™TAC, ARISTOFLEX™Velvet, ARISTOFLEX™A60, ARISTOFLEX™ECO T, ARISTOFLEX™PEA, ARISTOFLEX™PEA 70, NOVEMER™EC-1 , NOVEMER™EC 2, ARISTOFLEX™HMB, COSMEDIA™SP, FLOCARE™ET 25, FLOCARE™ET 75, FLOCARE™ET 26, FLOCARE™ET 30, FLOCARE™ET 58, FLOCARE™ PSD 30, VISCOLAM™AT 64, VISCOLAM™ AT 100, TEXIQUETM HE 10, TEXIQUETM HE 20, TEXIQUETM PQ 37.

[0096] Examples of thickening and / or gelling agents that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention as defined above, include polysaccharides consisting solely of oses, such as glucans or homopolymers of glucose, glucomannoglucans, xyloglycans, galactomannans whose degree of substitution (DS) of the D-galactose units on the main D-mannose chain is between 0 and 1, and more particularly between 1 and 0.25, such as galactomannans from cassia gum (DS = 1 / 5), locust bean gum (DS = 1 / 4), tara gum (DS = 1 / 3), guar gum (DS = 1 / 2), fenugreek gum (DS = 1).

[0097] Examples of thickening and / or gelling agents that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention as defined above, include polysaccharides consisting of ose derivatives, such as sulfated galactans and more particularly carrageenans and agar, uronans and more particularly algins, alginates and pectins, heteropolymers of oses and uronic acids and more particularly xanthan gum, gellan gum, exudates of gum arabic and karaya gum, glucosaminoglycans.

[0098] Examples of thickening and / or gelling agents that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, include cellulose, cellulose derivatives such as methylcellulose, ethylcellulose, hydroxypropylcellulose, silicates, starch, hydrophilic starch derivatives, polyurethanes.

[0099] Examples of stabilizing agents that can be combined with the plant extract in the cosmetic composition, the subject of the present invention as defined above, include microcrystalline waxes, and more particularly ozokerite, mineral salts such as sodium chloride or magnesium chloride, silicone polymers such as polysiloxane polyalkyl polyether copolymers.

[0100] Examples of solvents that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention as defined above, include water, organic solvents such as glycerol, diglycerol, glycerol oligomers, ethylene glycol, propylene glycol, butylene glycol, 1,3-propanediol, 1,2-propanediol, hexylene glycol, diethylene glycol, xylitol, erythritol, sorbitol, water-soluble alcohols such as ethanol, isopropanol or butanol, mixtures of water and said organic solvents.

[0101] Examples of thermal or mineral waters that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, include thermal or mineral waters having a mineralization of at least 300 mg / l, in particular Avene water, Vittel water, Vichy basin water, Uriage water, Roche Posay water, Bourboule water, Enghien-les-bains water, Saint-Gervais-les-bains water, Néris-les-bains water, Allevard-les-bains water, Digne water, Maizieres water, Neyrac-les-bains water, Lons le Saunier water, Rochefort water, Saint Christau water, Fumades water and Tercis-les-bains.

[0102] Examples of hydrotropic agents that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, include xylenesulphonates, cumenesulphonates, hexylpolyglucoside, 2-ethylhexylpolyglucoside, n-heptylpolyglucoside.

[0103] Examples of emulsifying surfactants that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, include non-ionic surfactants, anionic surfactants, cationic surfactants.

[0104] Examples of emulsifying non-ionic surfactants that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention as defined above, include fatty acid esters of sorbitol, such as the products marketed under the names MONTANE™40, MONTANE™60, MONTANE™70, MONTANE™80 and MONTANE™85; compositions comprising glycerol stearate and ethoxylated stearic acid of between 5 moles and 150 moles of ethylene oxide, such as the composition comprising ethoxylated stearic acid of 135 moles of ethylene oxide and glycerol stearate marketed under the name SIMULSOL™ 165; mannitan esters; ethoxylated mannitan esters; sucrose esters; methylglucoside esters;alkylpolyglycosides comprising a linear or branched, saturated or unsaturated aliphatic radical, and comprising from 14 to 36 carbon atoms, such as tetradecyl polyglucoside, hexadecyl polyglucoside, octadecyl poly glucoside, hexadecyl polyxyloside, octadecyl polyxyloside, eicosyl polyglucoside, dodecosyl polyglucoside, 2-octyldodecyl polyxyloside, 12-hydroxystearyl polyglucoside; compositions of linear or branched, saturated or unsaturated fatty alcohols, and comprising from 14 to 36 carbon atoms, and of alkylpolyglycosides as described above, for example the compositions marketed under the names MONTANOV™68, MONTANOV™14, MONTANOV™82, MONTANOV™202, MONTANOV™S, MONTANOV™WO18, MONTANOV™L, FLUID ANOV™20X and EASYNOV™.;

[0105] Examples of emulsifying anionic surfactants that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, include glyceryl stearate citrate, cetearyl sulfate, soaps such as sodium stearate or triethanolammonium stearate, N-acylated derivatives of salified amino acids, for example stearoyl glutamate.

[0106] Examples of emulsifying cationic surfactants that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, include amine oxides, quatemium-82 and the surfactants described in patent application WO96 / 00719 and mainly those whose fatty chain comprises at least 16 carbon atoms.

[0107] Examples of opacifying and / or pearlescent agents that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention as defined above, include sodium palmitate, sodium stearate, sodium hydroxy stearate, magnesium palmitate, magnesium stearate, magnesium hydroxy stearate, ethylene glycol monostearate, ethylene glycol distearate, polyethylene glycol monostearate, polyethylene glycol distearate, fatty alcohols containing from 12 to 22 carbon atoms.

[0108] Examples of texturizing agents that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, include N-acylated derivatives of amino acids, such as lauroyl lysine marketed under the name AMINOHOPE™LL, octenyl starch succinate marketed under the name DRYFLO™, myristyl polyglucoside marketed under the name MONTANOV™ 14, cellulose fibers, cotton fibers, chitosan fibers, talc, sericite and mica.

[0109] Examples of deodorant agents that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention as defined above, include alkali silicates, zinc salts such as zinc sulfate, zinc gluconate, zinc chloride, zinc lactate; quaternary ammonium salts such as cetyltrimethylammonium salts, cetylpyridinium salts; glycerol derivatives such as glycerol caprate, glycerol caprylate, polyglycerol caprate; 1,2 decanediol; 1,3 propanediol; salicylic acid; sodium bicarbonate; cyclodextrins; metal zeolites; TRICLOSAN™;aluminum bromohydrate, aluminum chlorohydrates, aluminum chloride, aluminum sulfate, aluminum zirconium chlorohydrates, aluminum zirconium trichlorohydrate, aluminum zirconium tetrachlorohydrate, aluminum zirconium pentachlorohydrate, aluminum zirconium octochlorohydrate, aluminum sulfate, sodium aluminum lactate, aluminum chlorohydrate glycol complexes, such as aluminum chlorohydrate propylene glycol complex, aluminum dichlorohydrate propylene glycol complex, aluminum sesquichlorohydrate propylene glycol complex, aluminum chlorohydrate polyethylene glycol complex, aluminum dichlorohydrate polyethylene glycol complex, aluminum sesquichlorohydrate polyethylene glycol complex.;

[0110] As examples of oils which can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, the following compounds can be mentioned:

[0111] Linear alkanes having from eleven to nineteen carbon atoms, such as n-undecane, n-dodecane, n-tridecane, n-tetradecane, n-pentadecane, n-hexadecane, n-heptadecane, n-octadecane, n-nonadecane;

[0112] Branched alkanes, containing from seven to forty carbon atoms, such as isododecane, isopentadecane, isohexadecane, isoheptadecane, isooctadecane, isononadecane or isoeicosane, or mixtures of some of them such as those listed below and identified by their INCI name: C7-8 isoparaffin, C8-9 isoparaffin, C9-11 isoparaffin, C9-12 isoparaffin, C9-13 isoparaffin, C9-14 isoparaffin, C9-16 isoparaffin, C10-11 isoparaffin, C10-12 isoparaffin, C10-13 isoparaffin, C11-12 isoparaffin, C11-13 isoparaffin, C11-14 isoparaffin, C12-14 isoparaffin, C12-20 isoparaffin, C13-14 isoparaffin, C13-16 isoparaffin;

[0113] Cycloalkanes optionally substituted by one or more linear or branched alkyl radicals;

[0114] White mineral oils, such as those marketed under the following names: - Marcol™52, Marcol™82, Drakeol™6VR, Eolane™! 30, Eolane™! 50; Hemisqualane (or 2,6,10-trimethyl-dodecane; CAS number: 3891-98-3), squalane (or 2,6,10,15,19,23-hexamethyltetracosane), hydrogenated polyisobutene or hydrogenated polydecene;

[0115] Mixtures of al canes comprising from 15 to 19 carbon atoms, said alkanes being linear alkanes, branched alkanes and cycloalkanes, and more particularly the mixture (Ml) which comprises for 100% of its mass, a mass proportion of branched alkanes greater than or equal to 90% and less than or equal to 100%; a mass proportion of linear alkanes greater than or equal to 0% and less than or equal to 9%, and more particularly less than 5% and a mass proportion of cycloalkanes greater than or equal to 0% and less than or equal to 1%, for example the mixtures marketed under the names Emogreen™L15 or Emogreen™L19;

[0116] Mixtures of linear alkanes such as the mixture of n-undecane and n-tridecane such as that marketed under the brand name Cetiol Ultimate™; mixtures of linear alkanes such as the mixture of n-dodecane and n-tetradecane such as that marketed under the brand name Vegelight™ 12-14;

[0117] Fatty alcohol ethers of formula (II):

[0118] - Z1-O-Z2 (II), in which Z1 and Z2, identical or different, represent a linear or branched alkyl radical containing from five to eighteen carbon atoms, for example dioctyl ether, didecyl ether, didodecyl ether, dodecyl octyl ether, dihexadecyl ether, (1,3-dimethyl butyl) tetradecyl ether, (1,3-dimethyl butyl) hexadecyl ether, bis(1,3-dimethyl butyl) ether or dihexyl ether;

[0119] Monoesters of fatty acids and alcohols of formula (III):

[0120] - R' 1-(C=O)-O-R'2 (III), in which R'1-(C=O) represents a saturated or unsaturated, linear or branched acyl radical containing from eight to twenty-four carbon atoms, and R' 2 represents, independently of R' 1, a saturated or unsaturated, linear or branched hydrocarbon chain containing from one to twenty-four carbon atoms, for example methyl laurate, ethyl laurate, propyl laurate, isopropyl laurate, butyl laurate, 2-butyl laurate, hexyl laurate, methyl cocoate, ethyl cocoate, propyl cocoate, isopropyl cocoate, butyl cocoate, 2-butyl cocoate, hexyl cocoate, methyl myristate, ethyl myristate, propyl myristate, isopropyl myristate, butyl myristate, 2-butyl myristate, hexyl myristate, octyl myristate, methyl palmitate, ethyl palmitate, propyl palmitate, isopropyl palmitate, butyl palmitate, 2-butyl palmitate, 11-hexyl palmitate,octyl palmitate, methyl oleate, ethyl oleate, propyl oleate, isopropyl oleate, butyl oleate, 2-butyl oleate, hexyl oleate, octyl oleate, methyl stearate, ethyl stearate, propyl stearate, isopropyl stearate, butyl stearate, 2-butyl stearate, hexyl stearate, octyl stearate, methyl isostearate, ethyl isostearate, propyl isostearate, isopropyl isostearate, butyl isostearate, 2-butyl isostearate, hexyl isostearate, isostearyl isostearate;,

[0121] Di-esters of fatty acids and glycerol of formula (IV) and formula (V):

[0122] - R'3-(C=O)-O-CH2-CH(OH)-CH2-O-(C=O)-R'4 (IV)

[0123] - R'5-(C=O)-O-CH2-CH[O-(C=O)-R'6]-CH2-OH (V), formulas (VI) (VII) in which R'3-(C=O), R'4-(C=O), R'5-(C=O), R'6-(C=O), identical or different, represent an acyl group, saturated or unsaturated, linear or branched, containing from eight to twenty-four carbon atoms;

[0124] Tri-esters of fatty acids and glycerol of formula (VI):

[0125] - R' 7-(C=O)-O-CH2-CH[O-(C=O)-R' ' 8] -CH2-O-(C=O)-R' ' 9 (VI), in which R'7-(C=O), R'8-(C=O) and R'9-(C=O), identical or different, represent an acyl group, saturated or unsaturated, linear or branched, comprising from eight to twenty-four carbon atoms;

[0126] Vegetable oils, such as phytosqualane, sweet almond oil, coconut oil, castor oil, jojoba oil, olive oil, rapeseed oil, peanut oil, sunflower oil, wheat germ oil, corn germ oil, soybean oil, cottonseed oil, alfalfa oil, poppy seed oil, pumpkin oil, evening primrose oil, millet oil, barley oil, rye oil, safflower oil, candlenut oil, passionflower oil, hazelnut oil, palm oil, shea butter, apricot kernel oil, calophyllum oil, sysymbrium oil, avocado oil, calendula, oils from flowers or vegetables;

[0127] Ethoxylated vegetable oils.

[0128] In the present application, the term "oils" means compounds and / or mixtures of compounds insoluble in water, having a liquid form at a temperature of 25°C.

[0129] Examples of waxes that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention as defined above, include beeswax, carnauba wax, candelilla wax, ouricoury wax, Japanese wax, cork fiber wax, sugar cane wax, paraffin waxes, lignite waxes, microcrystalline waxes, lanolin wax; ozokerite; polyethylene wax; silicone waxes; vegetable waxes; fatty alcohols and fatty acids that are solid at room temperature; glycerides that are solid at room temperature. In the present application, the term "waxes" means compounds and / or mixtures of compounds that are insoluble in water, which are in a solid form at a temperature greater than or equal to 45°C.

[0130] Examples of active ingredients that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, include vitamins and their derivatives, in particular their esters, such as retinol (vitamin A) and its esters (retinyl palmitate for example), ascorbic acid (vitamin C) and its esters, sugar derivatives of ascorbic acid (such as ascorbyl glucoside), tocopherol (vitamin E) and its esters (such as tocopherol acetate), vitamins B3 or BIO (niacinamide and its derivatives); compounds showing a skin lightening or depigmenting action such as co-undecelynoyl phenylalanine marketed under the name SEPIWHITE™MSH, SEPICALM™VG, the monoester and / or diester of glycerol of co-undecelynoyl phenylalanine, co-undecelynoyl dipeptides, arbutin, kojic acid, hydroquinone; compounds showing a soothing action, in particular SEPICALM™ S,allantoin and bisabolol; anti-inflammatory agents; compounds showing a moisturizing action such as urea, hydroxyureas, glycerol, polyglycerols, glycerolglucoside, diglycerolglucoside, polyglycerylglucosides, xylitylpoglucoside; plant extracts rich in polyphenols such as grape extracts, pine extracts, wine extracts, olive extracts; compounds showing a slimming or lipolytic action such as caffeine or its derivatives, ADIPOSLIM™, ADIPOLESS™, fucoxanthin; N-acylated proteins; N-acylated peptides such as MATRIXIL™; N-acylated amino acids; N-acylated partial protein hydrolysates; amino acids; peptides; total protein hydrolysates; soy extracts, for example Raffermine™; wheat extracts, for example TENSINE™ or GLIADINE™; plant extracts, such as plant extracts rich in tannins,plant extracts rich in isoflavones or plant extracts rich in terpenes; extracts of freshwater or marine algae; extracts of marine plants; marine extracts in general such as corals; essential waxes; bacterial extracts; ceramides; phospholipids; compounds showing an antimicrobial action or a purifying action, such as LIP ACIDE™ C8G, LIP ACIDE™ UG, SEPICONTROL™ A5; OCTOPIROX™ or SENSIVA™ SC50; compounds showing an energizing or stimulating property such as PHYSIOGENYL™, panthenol and its derivatives such as SEPICAP™ MP; anti-aging active ingredients such as SEPILIFT™ DPHP, LIPACIDE™ PVB, SEPIVINOL™, SEPIVITAL™, MANOLIVA™, PHYTO-AGE™, TIMECODE™; SURVICODE™; anti-photoaging active ingredients; active ingredients that protect the integrity of the dermo-epidermal junction; active ingredients that increase the synthesis of extracellular matrix components such as collagen and elastins,glycosaminoglycans; active ingredients that have a positive effect on chemical cellular communication, such as cytokines, or physical ones, such as integrins; active ingredients that create a sensation of "heating" on the skin, such as activators of cutaneous microcirculation (such as nicotinic acid derivatives) or products that create a sensation of "coolness" on the skin (such as menthol and derivatives); active ingredients that improve cutaneous microcirculation, for example, veinotonics; draining active ingredients; active ingredients with a decongestant effect, such as extracts of ginko biloba, ivy, horse chestnut, bamboo, ruscus, butcher's broom, centalla asiatica, fucus, rosemary, willow; skin tanning or browning agents, e.g., dihydroxyacetone (DHA), erythrulose, mesotartaric aldehyde, glutaraldehyde, glyceraldehyde, alloxan, ninhydrin,plant extracts, for example extracts of red woods of the genus Pterocarpus and the genus Baphia such as Pterocarpus santalinus, Pterocarpus osun, Pterocarpus soyauxii, Pterocarpus erinaceus, Pterocarpus indicus or Baphia nitida such as those described in European patent application EP 0 971 683; agents known for their action of facilitating and / or accelerating the tanning and / or browning of human skin, and / or for their action of coloring human skin, for example caratenoids (and more particularly beta carotene and gamma carotene), the product marketed under the brand name “Carrot oil” (INCI name: Daucus Carota, helianthus annuus Sunflower oil) by the company Provital, which contains carotenoids, vitamin E and vitamin K; tyrosine and / or its derivatives, known for their effect on accelerating the tanning of human skin in association with exposure to ultraviolet radiation,for example the product marketed under the brand name "SunTan Accelerator™" by the company Provital which contains tyrosine and riboflavins (vitamin B), the tyrosine and tyrosinase complex marketed under the brand name "Zymo Tan Complex" by the company Zymo Line, the product marketed under the brand name MelanoBronze™ (INCI name: Acetyl Tyrosine, Monk's pepper extract (Vitex Agnus-castus)) by the company Mibelle which contains acetyl tyrosine, product marketed under the brand name Unipertan VEG-24 / 242 / 2002 (INCI name: butylene glycol and Acetyl Tyrosine and hydrolyzed vegetable protein and Adenosine triphosphate) by the company UNIPEX, the product marketed under the brand name "Try-Excell™" (INCI name: Oleoyl Tyrosine and Luffa Cylindrica (Seed) Oil and Oleic acid) by the company Sederma which contains pumpkin seed extracts (or Loofah oil),the product marketed under the brand name “Actibronze™” (INCI name: hydrolyzed wheat protein and acetyl tyrosine and copper gluconate) by the company Alban Muller, the product marketed under the brand name Tyrostan™ (INCI name: potassium caproyl tyrosine) by the company Synerga, the product marketed under the brand name Tyrosinol (INCI name: Sorbitan Isostearate, glyceryl oleate, caproyl Tyrosine) by the company Synerga, the product marketed under the brand name InstaBronze™ (INCI name: Dihydroxyacetone and acetyl tyrosine and copper gluconate) marketed by the company Alban Muller, the product marketed under the brand name Tyrosilane (INCI name: methylsilanol and acetyl tyrosine) by the company Exymol; peptides known for their melanogenesis-activating effect, for example the product marketed under the brand name Bronzing SF Peptide powder (INCI name: Dextran and Octapeptide-5) by the company Infinitec Activos,the product marketed under the brand name Melitane (INCI name: Glycerin and Aqua and Dextran and Acetyl hexapeptide-1) comprising acetyl hexapeptide-1 known for its alpha-MSH agonist action, the product marketed under the brand name Melatimes Solutions™ (INCI name: Butylene glycol, Palmitoyl Tripeptide-40) by the company LIPOTEC, sugars and sugar derivatives for example the product marketed under the brand name Tanositol™ (INCI name: inositol) by the company Provital, the product marketed under the brand name Thalitan™ (or Phycosaccharide™ AG) by the company CODIF international (INCI name: Aqua and Hydrolyzed algin (Laminaria Digitata) and magnesium sulfate and manganese sulfate) containing an oligosaccharide of marine origin (guluronic acid and mannuronic acid chelated with magnesium and manganese ions), the product marketed under the brand name Melactiva™ (INCI name: Maltodextrin,Mucuna Pruriens Seed extract) by the company Alban Muller, compounds rich in flavonoids for example the product marketed under the brand name “Biotanning” (INCI name: Hydrolyzed citrus Aurantium dulcis fruit extract) by the company Silab and known to be rich in lemon flavonoids (hesperidin type); agents intended for the treatment of hair and / or body hair, for example agents protecting melanocytes of the hair follicle, intended to protect said melanocytes against cytotoxic agents responsible for the senescence and / or apoptosis of said melanocytes, such as agents mimetic of the activity of DOPAchrome tautomerase chosen from those described in the European patent application published under number EP 1 515 688 A2, synthetic molecules mimetic of SOD for example manganese complexes, antioxidant compounds for example cyclodextrin derivatives, siliceous compounds derived from ascorbic acid,lysine or arginine pyrrolidone carboxylate, combinations of mono- and diester of cinnamic acid and vitamin C, and more generally those cited in the European patent application published under number EP 1 515 688 A2.,

[0131] Examples of probiotics that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention as defined above, include different strains of Saccharomyces cerevisiae, Bacillus cereus var toyoi, Bacillus subtilis alone or in combination with Bacillus licheniformis, or strains of Enteroccocus faecium. These strains of microorganisms are generally combined with a solid support, for example calcium carbonate, dextrose or sorbitol.

[0132] Examples of antioxidant agents that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention as defined above, include EDTA and its salts, citric acid, tartaric acid, oxalic acid, BHA (butylhydroxyanisol), BHT (butylhydroxytoluene), tocopherol derivatives such as tocopherol acetate, mixtures of antioxidant compounds such as DISSOLVINE™ GL 47S marketed by the company Akzo Nobel under the INCI name: Tetrasodium Glutamate Diacetate.

[0133] Examples of sunscreens that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, include all those appearing in the cosmetic directive 76 / 768 / EEC amended annex VII.

[0134] Among the organic sunscreens that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, mention may be made of the family of benzoic acid derivatives such as para-aminobenzoic acids (PABA), in particular PABA monoglycerol esters, N,N25 propoxy PABA ethyl esters, N,N-diethoxy PABA ethyl esters, N,N-dimethyl PABA ethyl esters, N,N-dimethyl PABA methyl esters, N,N-dimethyl PABA butyl esters; the family of anthranilic acid derivatives such as homomenthyl-N-acetyl anthranilate; the family of salicylic acid derivatives such as amyl salicylate, homomenthyl salicylate, ethylhexyl salicylate, Tl phenyl salicylate, benzyl salicylate, p-isopropanolphenyl salicylate;the family of cinnamic acid derivatives such as ethylhexyl cinnamate, ethyl-4-isopropyl cinnamate, methyl-2,5-diisopropyl cinnamate, p-methoxypropyl cinnamate, p-methoxyisopropyl cinnamate, p-methoxyisoamyl cinnamate, p-methoxyoctyl cinnamate (p-methoxy 2-ethylhexyl cinnamate), p-methoxy 2-ethoxyethyl cinnamate, p-methoxycyclohexyl cinnamate, ethyl-a-cyano-P-phenyl cinnamate, 2-ethylhexyl-a-cyano-P-phenyl cinnamate, glyceryl diparamethoxy mono-2-ethylhexanoyl cinnamate;the family of benzophenone derivatives such as 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, 2-ethylhexyl-4'-phenylbenzophenone-2-5 carboxylate, 2-hydroxy-4-n-octyloxybenzophenone, 4-hydroxy-3-carboxybenzophenone; 3-(4'-methylbenzylidene)-d,l-camphor, 3 (benzylidene)-d,lcamphor, benzalkonium methosulfate camphor; urocanic acid, ethyl urocanate; the family of sulfonic acid derivatives such as 2-phenylbenzimidazole-5 sulfonic acid and its salts;the family of triazine derivatives such as hydroxyphenyl triazine, ethylhexyloxyhydroxyphenyl-4-methoxyphenyltriazine, 2,4,6-trianillino-(p-carbo-2'-ethylhexyl-l'-oxy)-l,3,5-triazine, 4,4-((6-(((l,l-dimethylethyl)amino)carbonyl)phenyl)amino)-l,3,5-triazine-2,4-diyl diimino) bis-(2-ethylhexyl) benzoic acid ester, 2-phenyl-5-methylbenzoxazole, 2,2'-hydroxy-5-methylphenylbenzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole; dibenzazine; dianisoylmethane, 4-methoxy-4"-tbutylbenzoylmethane; 5-(3,3-dimethyl-2-norbodylidene)-3-pentan-2-one; the family of diphenylacrylate derivatives such as 2-ethylhexyl-2-cyano-3,3-diphenyl-2-propenoate, ethyl-2-cyano-3,3-diphenyl-2-propenoate; the family of polysiloxanes such as benzylidene siloxane malonate.;

[0135] Among the inorganic sunscreens, also called "mineral screens", which can be combined with the brown algae extract in the cosmetic composition, object of the present invention as defined above, mention may be made of titanium oxides, zinc oxides, cerium oxide, zirconium oxide, yellow, red or black iron oxides, chromium oxides. These mineral screens can be micronized or not, have undergone surface treatments or not and may optionally be presented in the form of aqueous or oily pre-dispersions.

[0136] The present invention also relates to a method for cosmetic treatment of the skin, to prevent or reduce (attenuate or treat) the signs of aging, in particular the unsightly signs of sagging skin, comprising the application thereto of an effective amount of an extract of brown algae of the species Himanthalia Elongata as defined above or of the cosmetic composition as defined above.

[0137] According to a particular aspect of the method as defined above, said application to the skin, said extract or said composition is applied to a part of the skin of the face or body showing unsightly signs of sagging skin, at a rate of one or two daily applications, at least for 7 days, in particular at least for 14 days, even more particularly for 28 days.

[0138] Bibliography

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[0140] (2) Contet-Audonneau JL, Jeanmaire C, Pauly G. A histological study of human wrinkle structures: comparison between sun-exposed areas of the face, with or without wrinkles, and sun-protected areas. Br J Dermatol. 1999;140(6): 1038-1047

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[0143] (5) Langton, A. K., Halai, P., Griffiths, C. E., Sherratt, M. J., & Watson, R. E. The impact of intrinsic aging on the protein composition of the dermal -epidermal junction. Mechanisms of ageing and development, Volume 156, June 2016, Pages 14-16

[0144] (6) Féru J, Delobbe E, Ramont L, Brassart B, Terryn C, Dupont-Deshorgue A, Garbar C, Monboisse JC, Maquart FX,Brassart-Pasco S. Aging decreases collagen IV expression in vivo in the dermo-epidermal junction and in vitro in dermal fibroblasts: possible involvement of TGF-pi. Eur J Dermatol. 2016 Aug l;26(4):350-60.

[0145] (7) Tuusa, J., Kokkonen, N., & Tasanen, K. (2021). BP180 / Collagen XVII: A Molecular View. International Journal of Molecular Sciences, 2021 Nov 12;22(22), 12233 (8) Watanabe M, Natsuga K, Nishie W, et al. Type XVII collagen coordinates proliferation in the interfollicular epidermis. Elife. 2017 Jul ll;6:e26635

[0146] (9) Lovell CR, Smolensk! KA, Duance VC, Light ND, Young S, Dyson M. Type I and III collagen content and fibre distribution in normal human skin during ageing. Br J Dermatol.

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[0148] (10)Vogel V, Sheetz M. Local force and geometry sensing regulate cell functions. Nat Rev Mol Cell Biol. 2006 Apr;7(4):265-75

[0149] (11) Discher DE, Janmey P, Wang YL. Tissue cells feel and respond to the stiffness of their substrate. Science. 2005 Nov 18;310(5751): 1139-43

[0150] (12) Hinz B, Gabbiani G. Mechanisms of force generation and transmission by myofibroblasts. Curr Opin Biotechnol. 2003 Oct;14(5):538-46

[0151] (13) Hinz B. Masters and servants of the force: the role of matrix adhesions in myofibroblast force perception and transmission. Eur J Cell Biol. 2006 Apr;85(3-4): 175-81)

[0152] (14) Courts L, Bamber J, Miller N. Multi-directional in vivo tensile skin stiffness measurement for the design of a reproducible tensile strain elastography protocol. Skin Res Technol. 2013 Feb;19(l):e37-44

[0153] (15) Kruglikov IL, Scherer PE. Skin aging: are adipocytes the next target? Aging (Albany NY). 2016 Jul; 8(7): 1457-1469

[0154] (16) Hay dont V, Neiveyans V, Perez P, et al. Fibroblasts from the Human Skin Dermo- Hypodermal Junction are Distinct from Dermal Papillary and Reticular Fibroblasts and from Mesenchymal Stem Cells and Exhibit a Specific Molecular Profile Related to Extracellular Matrix Organization and Modeling. Cells. 2020 Feb; 9(2): 368

[0155] (17) Sommer, G, Eder, M., Kovacs, L., Pathak, H., Bonitz, L., Mueller, C., ... & Holzapfel, G. A. Multiaxial mechanical properties and constitutive modeling of human adipose tissue: a basis for preoperative simulations in plastic and reconstructive surgery. Acta biomaterialia 2013, Nov;9(ll): 9036-9048

[0156] (18) Cox, S., Hamilton Turley, G, Rajauria, G., Abu-Ghannam, N., & Jaiswal, A.K. Antioxidant potential and antimicrobial efficacy of seaweed Himanthalia elongata) extract in model food systems. Journal of Applied Phycology 2013, vol. 26, no 4, 3 : 1823-183

[0157] Les exemples suivants illustrent l'invention, sans toutefois la limiter.

[0158] Example 1: Extraction according to the method of the invention of the algae Himanthalia elongata to obtain the extract according to the invention (EHE) 50 kg of dried and ground algae of Himanthalia elongata is brought into contact with 600 kg of 96% ethanol in water. The mixture is brought to 40°C and stirred for 2 hours. Once the biomass is separated from the extract, it is concentrated to obtain a dry extract of the order of 20% and then 150 kg of 1,3-propanediol is added. The mixture is homogenized and the evaporation under vacuum of the residual ethanol is continued. After complete desolvation and filtration at 0.2 µm on a cellulosic filter, a liquid extract free of chlorophyll and triglyceride is obtained and referenced (EHE).

[0159] The extract (EHE) thus obtained is a brown liquid extract, with a dry extract of 1.7% and which contains 0.011% by mass of sulfoquinovosyldiacylglycerol (SQDG).

[0160] Example 2: Evaluation of the anti-sagging and firming effect on the face Principle of the method:

[0161] These assessments are carried out by measuring the following criteria:

[0162] - Measurement of facial firmness (Dynaskin)

[0163] - Measurement of the surface area of ​​the nasolabial fold by fringe projection (AEVA-HE)

[0164] These evaluations were carried out on a population of 63 female volunteers, with an average age of 59 years, presenting a visible nasolabial fold which was divided into 2 equal groups of 31 and 32 volunteers respectively (group I and II). Each member of group (I) applied to their face twice daily and for a period of 28 days the formula (Fl) containing 2% of Himanthalia Elongata extract according to the invention (EHE) and each member of group (II) applied to their face twice daily and for a period of 28 days the formula (F0) Placebo.

[0165] The composition of the tested formulas is described below.

[0166] [Table 1]

[0167] Before application of the products and after 28 days, the measurement of the surface of the nasolabial fold (in mm 2 ) was performed by in vivo fringe projection using the AEVA-HE system. Means and standard deviations were calculated at each time and for each product.

[0168] Before product application and after 28 days, skin firmness was measured using the Dynaskin. This is a complement to the dermaTop system to provide a firmness assessment with a complete non-contact method. It produces a deformation close to the clinical approach by blowing air perpendicular to the area of ​​interest. The 3D sensor, using fringe projection techniques, captures the surface appearance just before the deformation, then at the moment the deformation is applied, and just after it.

[0169] The acquisition is carried out on a randomized cheek and the parameter studied is the surface (mm 2 ) of the deformation.

[0170] Statistical elements:

[0171] Values ​​are expressed as mean + / - standard deviation.

[0172] The percentages versus placebo were calculated as follows:

[0173] %A = [((TAt28 - TAtO) EHE - (TAt28 - TAtO)piace bo) / (TAtOEHE + (TAt28 - TAtO)pi ace bo)] x 100, where TA represents the average value obtained on the area treated with Himanthalia Elongata extract, t0: before product application and t28: after 28 days of product application.

[0174] Intra-group statistical analysis was performed by paired Student's t-test. Inter-group statistical analysis was performed by unpaired Student's t-test.

[0175] The significance threshold was set at 5%. Results:

[0176] A - Measurement of the surface area of ​​the nasolabial fold

[0177] The area (mm2) of the nasolabial fold at DO and its variation after 28 days of application versus DO (D28-D0) are shown in the table below. Values ​​are expressed as mean ± SD. NS: Not significant

[0178] [Table 2]

[0179] The difference in variation of the nasolabial fold area (mm2) versus placebo after 28 days of application is shown in the table below (*p<0.05). [Table 3]

[0180] After one month of application, we were able to observe that the formula containing 2% of the Himanthalia elongata extract according to the invention significantly reduced the surface area of ​​the nasolabial fold versus placebo by 7.1% and therefore reduced skin sagging. B - Measurement of facial firmness (surface of deformation with Dynaskin)

[0181] The deformation surface (mm2) at DO and its variation after 28 days of application versus

[0182] DO (D28-D0) are shown in the table below. Values ​​are expressed as mean ± SD. NS: Not significant, *p<0.05 [Table 4]

[0183] The difference in variation of the deformation surface (mm2) versus placebo after 28 days of application is shown in the table below (*p<0.05)

[0184] [Table 5]

[0185] After one month of application of the formula containing 2% Himanthalia Elongata extract significantly reduced the deformation area created by Dynaskin versus placebo by 4.3% and therefore improved skin firmness.

[0186] Example 3: Reinforcement of mechanical properties at the dermo-epidermal junction A - Stimulation of collagen IV expression

[0187] Principle of the method:

[0188] Evaluation of collagen IV expression by immunofluorescence

[0189] Fibroblasts (pool of 4 donors - average age 30 years) are thawed and amplified for 4 days. They are then seeded in 96-well plates and incubated at 37°C under 5% CO2 for 3 days. The cells are then treated for 72 hours in quadruplicate (n=4) in a medium containing 2% FCS (fetal calf serum) with each of the following elements:

[0190] - The extract of Himanthalia Elongata according to the invention (EHE) at 0.01%

[0191] - 1,3-propanediol at 0.01% - Vitamin C at 0.001%, positive reference

[0192] - a fraction of the extract of Himanthalia Elongata (EHE) purified in SQDG (composition C2), at the concentration equivalent to that found in the extract of Himanthalia Elongata (EHE)

[0193] - an extract of Himanthalia Elongata, obtained according to the process described in patent application FR 3 082430 Al, not containing SQDG (composition Cl'), tested at 0.01%.

[0194] Cells are fixed, permeabilized, and specific collagen IV labeling is performed using a fluorescent antibody. Image acquisition is performed using a Thermo Fisher Cell Insight CX7 HCS microscope. They are then quantified by compartmental analysis to assess fluorescence intensity (AU: arbitrary units) per 1000 cells / well.

[0195] Statistical elements:

[0196] Values ​​are expressed as mean fluorescence intensity (AU) + / - standard deviation. For each condition, the effect percentages were calculated as follows:

[0197] % effect = 100 x [mean (condition) - mean (untreated condition)] / [mean (untreated condition)]

[0198] The statistical analysis was performed using a one-way Student test with a significance threshold set at 5%, comparing the conditions two by two. A difference between the effectiveness of two products was considered:

[0199] - Significant if p < 0.05;

[0200] - Said to be “at the limit of significance” noted LS if 0.05 < p < 0.1;

[0201] - And not significant if p > 0.1.

[0202] Results :

[0203] As shown in the table below, vitamin C causes an increase in collagen IV expression of +55%LS (p<0.1)

[0204] The Himanthalia elongata extract according to the invention at 0.01% also stimulates the expression of collagen IV by +107%* (p<0.05) unlike the corresponding solvent.

[0205] Composition C2 is also able to increase the expression of collagen IV by +166%* (p<0.05), demonstrating the role of SQDG in the biological activity of the extract.

[0206] The Himanthalia elongata extract according to the invention is more effective than the Cl' composition tested at the same concentration (+107%* vs +57% LS). [Table 6]

[0207] B - Stimulation of collagen expression XVII Principle of the method:

[0208] Evaluation of collagen XVII expression by immunofluorescence

[0209] Explants of young and old skin (26 and 54 years old, respectively) were treated by topical application with a formula containing 2% Himanthalia Elongata extract (formulation Fl') for 7 days and compared with treatment with the placebo formula (formulation FO'). The Fl' and FO' formulations are shown in the table below. After fixation, they were embedded in paraffin and then sectioned before being labeled with a specific fluorescent antibody against collagen XVII. The intensity of the labeling was observed under a microscope. [Table 7] Statistical elements:

[0210] Each condition was performed in triplicate (n=3). Values ​​are expressed as the mean of the fluorescence intensity (AU: arbitrary units) normalized to the selected region of interest + / - standard deviation. For each condition, the effect percentages were calculated as follows:

[0211] % effect = 100 x [mean (condition) - mean (untreated condition)] / [mean (untreated condition)]

[0212] The statistical analysis was performed using a one-way Student test with a significance threshold set at 5%, comparing the conditions two by two. A difference between the effectiveness of two products was considered:

[0213] - Significant if p < 0.05;

[0214] - Said to be “at the limit of significance” noted LS, if 0.05 < p < 0.1;

[0215] - And not significant if p > 0.1.

[0216] Results :

[0217] As shown in the table below, with age, the expression of collagen XVII decreases by -10%* (p<0.05). The Himanthalia elongata extract according to the invention (EHE) allows the increase in the expression of collagen XVII by +12%* (p<0.05) unlike the placebo formula (formula F0').

[0218] [Table 8]

[0219] Conclusion: The Himanthalia elongata extract (EHE) according to the invention is capable of strengthening the mechanical properties at the dermo-epidermal junction by increasing the expression of collagen IV and XVII.

[0220] Example 4: Reinforcement of dermal mechanical properties through mechanobiology A - Stimulation of integrin expression [31

[0221] Principle of the method Evaluation of integrin expression [31 by immunofluorescence

[0222] Fibroblasts (pool of 4 donors - average age 30 years) are thawed and amplified for 4 days. They are then seeded in 96-well plates and incubated at 37°C under 5% CO2 for 3 days. The cells are then treated for 72 hours in quadruplicate (n=4) in a medium containing 2% FCS (fetal calf serum) with each of the following elements:

[0223] - The extract of Himanthalia Elongata according to the invention at 0.01% (EHE)

[0224] - 1,3-propanediol at 0.01%

[0225] - Vitamin C at 0.001%, positive reference

[0226] - an extract of Himanthalia Elongata, obtained according to the process described in patent application FR 3082430 A1, not containing SQDG (composition Cl'), at 0.01%

[0227] Cells are fixed, permeabilized, and specific labeling of integrin pi is performed using a fluorescent antibody. Image acquisition is performed using a Thermo Fisher Cell Insight CX7 HCS microscope. They are then quantified by compartmental analysis to assess the fluorescence intensity (AU: arbitrary units) per 1000 cells / well.

[0228] Statistical elements:

[0229] Values ​​are expressed as mean fluorescence intensity (AU) + / - standard deviation. For each condition, the effect percentages were calculated as follows:

[0230] % effect = 100 x [mean (condition) - mean (untreated condition)] / [mean (untreated condition)]

[0231] The statistical analysis was performed using a one-way Student test with a significance threshold set at 5%, comparing the conditions two by two. A difference between the effectiveness of two products was considered:

[0232] - Significant if p < 0.05;

[0233] - Said to be “at the limit of significance” if 0.05 < p < 0.1;

[0234] - And not significant if p > 0.1.

[0235] Results :

[0236] As shown in the table below, TGF-P increases the expression of integrin pi by +53%** (p<0.01).

[0237] The Himanthalia elongata extract (EHE) according to the invention stimulates the expression of integrin pi by +41%** (p<0.01) and more strongly than the corresponding solvent. It is more effective than the Cl' composition, which stimulates only by +24%* (p<0.05) the protein level of integrin pi. [Table 9]

[0238] B - Stimulation of the expression of integrin a-SM actin Principle of the method: Evaluation of the expression of a-SM actin by western blotting

[0239] Fibroblasts (pool of 4 donors - average age 30 years) are thawed and amplified for 4 days. They are then seeded in 6-well plates and incubated at 37°C under 5% CO2 for 3 days. The cells are then treated for 72 hours in quadruplicate (n=4) in a medium containing 2% FCS (fetal calf serum) with: - The Himanthalia Elongata extract according to the invention at 0.01% (EHE)

[0240] - 1,3-propanediol at 0.01%

[0241] - Vitamin C at 0.001%, positive reference

[0242] - an extract of Himanthalia Elongata, obtained according to the process described in patent application FR 3082430 A1, not containing SQDG (composition Cl'), at 0.01% The proteins are extracted and deposited on stain-free gel. After migration, they are transferred to a nitrocellulose membrane and incubated with an antibody specific for α-SM actin. The quantity of α-SM actin is quantified and normalized relative to the total quantity of proteins deposited. Statistical elements: no statistical element on this type of test, only one protein deposit per condition.

[0243] Results :

[0244] As shown in the table below, TGF-P increases the protein level of α-SM actin by +196%. The Himanthalia elongata extract (EHE) according to the invention at 0.01% stimulates the expression of α-SM actin by +61%, unlike the corresponding solvent and the Cl' composition.

[0245] [Table 10]

[0246] C - Stimulation of the expression of the elastic modulus in the extracellular matrix Principle of the method: Measurement of the elastic modulus or Young's modulus by atomic force microscope Young and old dermal fibroblasts (26 and 61 years old respectively) are cultured in a Petri dish containing type I collagen lattices at 37°C under 5% CO2 for 24 hours. The cells are then treated for 72 hours in quadruplicate (n=4) in a medium containing 2% FCS (fetal calf serum) with:

[0247] - The extract of Himanthalia Elongata (EHE) according to the invention at 0.01% and its corresponding solvent 1,3-propanediol

[0248] - TGF-P at 10 ng / mL, positive reference

[0249] The elastic modulus or Young's modulus is measured at the collagen I lattice near the fibroblast by atomic force microscopy.

[0250] Five measurements are performed per condition and each condition is performed in triplicate (n=3). This biophysical parameter allows us to account for the traction force exerted by the fibroblast on its extracellular matrix.

[0251] Statistical elements:

[0252] Values ​​are expressed as the mean of the elastic modulus + / - standard deviation. For each condition, the percentage effects were calculated as follows:

[0253] % effect = 100 x [mean (condition) - mean (untreated condition)] / [mean (untreated condition)]

[0254] The normal distribution of the data and the homogeneity of variances were verified using the Shapiro-Wilk and Barlett tests respectively. The samples followed a normal distribution but the variances were not equal. Statistical analysis was performed using a Welch test with a significance threshold set at 5%, comparing the conditions two by two. A difference between the effectiveness of two products was considered significant if p < 0.05.

[0255] Results :

[0256] As shown in the table below, with age, the elastic modulus decreases by -50%*** (p<0.001). As expected, TGF-P increases by +178%*** (p<0.001) the elastic modulus of aged fibroblasts, the ^Himanthalia elongata extract according to the invention (EHE) stimulates the tensile force of aged fibroblasts by +117%*** (p<0.001) unlike the corresponding solvent. [Table 11]

[0257] Conclusion: The Himanthalia elongata extract according to the invention increases the expression of the integrin mechanoreceptor [31, stress fibers composed of α-SM actin as well as the traction forces exerted by the fibroblast on its extracellular matrix. The mechanotransduction machinery is therefore stimulated, reinforcing the mechanical properties of the dermis: the skin is firmer, skin sagging is therefore reduced.

[0258] Example 5: Reinforcement of mechanical properties at the dermis-hypodermis interface A - Stimulation of the elastic modulus in the deep dermis Principle of the method: Evaluation of the rigidity of the junction between the dermis and the hypodermis by atomic force microscopy

[0259] Explants of young and old skin (26 and 54 years old respectively) were treated by topical application with a formula containing 2% of Himanthalia Elongata extract according to the invention (formula Fl') for 7 days. After fixation, they were frozen and then cryo-cut. Each condition was carried out in triplicate (n=3)

[0260] The elastic modulus or Young's modulus is measured at the interface between the dermis and the hypodermis by atomic force microscopy. 3 measurements are made. It represents the rigidity of this junction.

[0261] Statistical elements:

[0262] Values ​​are expressed as mean elastic modulus + / - standard error of the mean (SEM). For each condition, the effect percentages were calculated as follows:

[0263] % effect = 100 x [mean (condition) - mean (untreated condition)] / [mean (untreated condition)]

[0264] The statistical analysis was performed using a one-way Student test with a significance threshold set at 5%, comparing the conditions two by two. A difference between the effectiveness of two products was considered:

[0265] - Significant if p < 0.05;

[0266] - Said to be “at the limit of significance” if 0.05 < p < 0.1;

[0267] - And not significant if p > 0.1.

[0268] Results :

[0269] As shown in the table below, with age, the elastic modulus decreases by -69%*** (p<0.001). The Himanthalia elongata extract according to the invention (EHE) increases the rigidity of the dermo-hypodermal junction by +69%*** (p<0.001) on aged explants unlike the placebo formula (formula F0'). [Table 12]

[0270] B - Stimulation of type I procollagen Principle of the method: Evaluation of the quantity of type I procollagen in a fibroblast / adipocyte coculture model.

[0271] Aged dermal fibroblasts (60 years) are co-cultured with mature adipocytes encapsulated in an inert peptide hydrogel for 48 hours at 37°C 5% CO2. They are then treated for 48 hours with the Himanthalia elongata extract according to the invention at 0.01% (EHE) and its solvent. The supernatants are isolated and the secretion of type I procollagen is measured.

[0272] Statistical elements: Each condition was tested in triplicate (n=3). Values ​​are expressed as mean type I procollagen in ng / mL + / - standard deviation. For each condition, the effect percentages were calculated as follows:

[0273] % effect = 100 x [mean (condition) - mean (untreated condition)] / [mean (untreated condition)]

[0274] Statistical analysis was performed using a one-way Student test with a significance threshold set at 5%, comparing the conditions two by two. A difference between the efficacy of two products was considered significant if p < 0.05.

[0275] Results :

[0276] As shown in the table below, the Himanthalia elongata extract according to the invention (EHE) increases the secretion of type I procollagen by +42%* when fibroblasts are co-cultured with adipocytes.

[0277] [Table 13]

[0278] Conclusion :

[0279] The Himanthalia elongata extract according to the invention (EHE) increases the rigidity of the dermo-hypodermal junction. It also stimulates the secretion of type I procollagen in a fibroblast / adipocyte coculture model. The mechanical properties of human skin are strengthened, the skin is firmer and skin sagging is reduced.

Claims

CLAIMS 1. Extract of brown algae of the species Himanthalia Elongata comprising a content greater than or equal to 100 mg / kg of sulfoquinovosyldiacylglycerol (SQDG) dissolved in 1,3-propanediol, said extract of brown algae of the species Himanthalia Elongata being obtained: either by the process comprising the following successive steps: A step a) of providing a ground brown algae of the Himanthalia Elongata species, A step b) of extracting the sulfoquinovosyldiacylglycerol (SQDG), the chlorophyll and optionally the triglycerides present in said ground brown algae made available in step a), by mixing the latter with a first solvent SI of alcoholic and / or apolar type, to obtain a first liquid phase comprising said solvent SI, the residual ground brown algae not dissolved in said solvent SI and the sulfoquinovosyldiacylglycerol (SQDG), the chlorophyll, and optionally the triglycerides dissolved in said solvent SI, A step c) of separation by filtration, from said first liquid phase obtained at the end of step b), of said residual brown algae ground material not dissolved in said solvent SI, to obtain a second liquid phase comprising said solvent SI, sulfoquinovosyldiacylglycerol (SQDG), chlorophyll, and optionally the triglycerides dissolved in said solvent SI, Optionally, a step d) of concentrating said second liquid phase obtained at the end of step c), by evaporation, at least partially, of said first solvent SI, to obtain a second concentrated liquid phase comprising said solvent SI, sulfoquinovosyldiacylglycerol (SQDG), chlorophyll, and optionally the triglycerides dissolved in said solvent SI, A step e) of mixing said second liquid phase obtained at the end of step c) or said second concentrated liquid obtained at the end of step d), with 1,3-propanediol, to obtain a third liquid phase comprising a mixture of said solvents SI and 1,3-propanediol, sulfoquinovosyldiacylglycerol (SQDG), chlorophyll and optionally triglycerides, A step I) of elimination by evaporation of the first solvent SI from said third liquid phase obtained in step e), to obtain a fourth liquid phase comprising 1,3-propanediol, chlorophyll and optionally the triglycerides not dissolved in 1,3-propanediol and sulfoquinovosyldiacylglycerol (SQDG) dissolved in 1,3- propanediol, and A step g) of separation by filtration, from said fourth liquid phase obtained in step f), of the chlorophyll and optionally of the triglycerides not dissolved in the 1,3-propanediol, to obtain said expected brown algae extract; or by the process comprising the following successive steps: A step h) of providing a ground brown algae of the Himanthalia Elongata species. A step i) of extracting the sulfoquinovosyldiacylglycerol (SQDG), the chlorophyll and optionally the triglycerides present in said ground brown algae made available in step h), by mixing the latter with a first SI solvent of alcoholic and / or apolar type and 1,3-propanediol, to obtain a fifth liquid phase comprising the SI solvents and the 1,3-propanediol, the residual ground brown algae, the sulfoquinovosyldiacylglycerol (SQDG), the chlorophyll and optionally the triglycerides, A step j) of removing by evaporation said first solvent SI present in said fifth liquid phase obtained in step i), to obtain a sixth liquid phase comprising 1,3-propanediol, said residual brown algae ground material, chlorophyll and optionally triglycerides not dissolved in 1,3-propanediol and sulfoquinovosyldiacylglycerol (SQDG) dissolved in 1,3-propanediol, and A step k) of separation by filtration, from said sixth liquid phase obtained in step j), of said residual brown algae ground material, of the chlorophyll and optionally of the triglycerides not dissolved in 1,3-propanediol, to obtain said expected brown algae extract.

2. Extract of brown algae of the species Himanthalia Elongata according to claim 1, comprising a content greater than or equal to 100 mg / kg, in particular greater than or equal to 110 mg / kg, of sulfoquinovosyldiacylglycerol (SQDG) dissolved in 1,3-propanediol.

3. Extract of brown algae of the species Himanthalia Elongata according to one of claims 1 or 2, for which the parameter a* according to the CIELAB color space is greater than or equal to -5.

4. Extract of brown algae of the species Himanthalia Elongata according to any one of claims 1 to 3, characterized in that its mass content of dry matter (dry extract) is greater than or equal to 1% and more particularly greater than or equal to 1.5%.

5. Use of an extract of brown algae of the species Himanthalia Elongata according to any one of claims 1 to 4, as a cosmetic active ingredient for preventing or reducing the unsightly signs of sagging skin.

6. Cosmetic composition for topical use comprising a cosmetically effective amount of an extract of brown algae of the species Himanthalia Elongata according to any one of claims 1 to 4, and at least one cosmetically acceptable ingredient.

7. Composition according to claim 6, characterized in that the concentration by weight of said extract is, for 100% by mass of said composition, between 0.1% by mass and 10% by mass, preferably between 0.5% by mass and 2% by mass.

8. Cosmetic treatment process for the skin, to prevent or reduce the unsightly signs of sagging skin, comprising the application thereto of an effective amount of an extract of brown algae of the species Himanthalia Elongata according to any one of claims 1 to 4 or of the cosmetic composition according to one of claims 6 or 7.

9. Method according to claim 8, characterized in that said application to the skin of said extract or said composition is applied to a part of the skin of the face or body showing unsightly signs of sagging skin, at a rate of one or two daily applications, for at least 7 days, in particular for 28 days.

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