Use of an extract of the brown alga alaria esculenta to protect the scalp from the harmful effects of pollution

Abstract

The invention relates to the cosmetic use of an extract of the brown alga Alaria esculenta as a cosmetic active ingredient for protecting the scalp against the harmful effects of indoor or outdoor atmospheric pollutants, wherein the pollutants are selected from among: toxic gases such as sulphur, sulphur dioxide and ozone; heavy metals such as cobalt, mercury, cadmium, lead and nickel; noble metals such as rhodium, platinum and palladium; volatile organic compounds (or VOCs); tobacco smoke, such as cigarette smoke, and dust.

Description

[0001]Use of an extract of the brown algae Alaria Esculenta to protect the scalp from the harmful effects of pollution The present invention relates to a use of an extract of the brown algae Alaria Esculenta to protect the scalp from the harmful effects of indoor or outdoor air pollutants. The effects of pollution on human health constitute health problems encountered on a global scale. Indeed, urban environments are regularly exposed to various air and atmospheric pollutants, the action of which can be harmful to the health of human beings, by deteriorating the functioning of certain organs such as the lungs and eyes. By constituting a barrier between the human body and the external environment, the keratinous materials constituting the human body, and more particularly the skin, mucous membranes, scalp and hair,are in contact with these air and atmospheric pollutants, leading to visible external effects characterized by the appearance and increase of wrinkles, by a dull complexion, by a lack of uniformity of the complexion (dyschromia phenomenon), by the appearance and increase of pigment spots (hyper-pigmentation phenomenon) or by a modification and alteration of the effectiveness of the skin barrier. The systemic effects of exposure to different types of pollutants are described in the literature, and the effects at the cutaneous level are increasingly studied. Among the most harmful pollutants, we can cite toxic gases such as carbon monoxide, nitrogen oxides such as nitrogen dioxide, sulfur oxides such as sulfur dioxide, ozone; heavy metals such as cobalt, mercury, cadmium and nickel, indoor pollutants such as volatile organic compounds (VOCs) and cigarette smoke,atmospheric particles which are microscopic solids suspended in the Earth's atmosphere such as microparticles identified by the acronyms PM2.5 and PM10 [1]. These pollutants are known to cause visible negative external effects on the skin, scalp and hair. Indeed, our scalp, our hair, like our skin, are daily confronted with pollution: dust, exhaust fumes, industrial emissions, cigarette smoke... which play an important role in the beauty of the hair. Pollution affects the health of the scalp, and ultimately the health and beauty of the hair, skin and scalp. In particular,Pollution can cause inflammation and irritation of the scalp. It is therefore important to protect the scalp in order to limit the harmful effects on the health of the scalp, hair, and skin. The scalp is an area of ​​skin where hair grows. The scalp's role is to protect the skull and brain through the presence of hair, but also through the thermoregulation of the entire head, which is achieved by filtering the sun's rays. The scalp adheres effectively to the galea capitis, the fascia that directly covers the skull bone, with interposition of connective tissue. The scalp is made up of a superficial zone, the epidermis, which is poor in pigment and well protected from light by the hair, and a deeper zone,the dermis in which the hair bulbs are present in a very dense manner. The scalp is crossed by capillaries which supply the hair with blood. Other important functions are performed by the sebaceous glands and the sweat glands which, thanks to sebum and sweat, ensure the protection and lubrication of the scalp and hair. Each bulb corresponds to the outlet of a sebaceous gland. If the sebaceous glands are very active and secrete a lot of sebum, the hair will be oily, easily covering itself with a lubricating secretion. If, on the contrary, the activity of the sebaceous glands is reduced, they produce little sebum and the hair will be dry. The skin is composed of a superficial layer called the epidermis, and a deep layer called the dermis beneath which is the hypodermis or subcutaneous fatty tissue. The epidermis is separated from the dermis by the basement membrane. The epidermis,or covering epithelium, is made up of four types of cells, the most important of which, that made up of keratinocytes, is distributed in numerous rows of cells that overlap and are subdivided into five layers: the basal layer, the spinous layer, the granular layer, the shiny layer, the horny layer. Keratinocytes are formed and reproduce in the deepest part (basal layer), and from there, following the aging process, they gradually rise to the surface, producing internally keratin, which has a particular resistance to external aggressions (soaps, oils, solvents, hot and cold, visible and ultraviolet radiation, pathogenic germs and fungi, etc.). The detachment from the surface of already dead cells is usually invisible. On the other hand, if for some reason, due to particular problems of the scalp,Cell clumps form; their detachment becomes visible in the form of scales or dandruff. The scalp is made of skin and therefore can be subject to alterations, abnormalities, disturbances or diseases. Among these alterations of the scalp, we can mention itching, sometimes accompanied by tingling, redness, burning or generalized irritation. Itchy scalp is a sensation that leads those affected to scratch, which is often associated with pain. Itchy scalp can be triggered both by chemicals used in many cosmetic products, but also by the toxic effects of air pollution. Itchy scalp can also be associated with psoriasis, dandruff, seborrhea, folliculitis, dry skin, seborrheic dermatitis,to atopic dermatitis and eczema. This itchy scalp can lead to hair loss or thinning. Among the various causes of itching, dandruff is the most common. Intense itching, skin redness and hair loss are often associated with oily dandruff characterized by scales that remain attached to the scalp. To date, four biological components are believed to be involved in the appearance of visible external negative effects and disorders [2, 3, 4] caused by pollutants: - The oxidative component: pollutants cause increased production of free radicals by skin cells, leading to the generation of carbonyl proteins, peroxidized lipids or even the appearance of DNA damage - in parallel,a decrease in enzymatic and non-enzymatic antioxidant systems is observed -The inflammatory component: the effects of polluting agents induce an induction of a cascade of inflammatory reactions [5] -The activation of a specific hydrocarbon receptor (AhR) - The alteration of the cutaneous microflora These pathways are generally activated synergistically by the combination of different polluting agents. It is clear that there is an increasing demand for developing and preparing topical compositions comprising chemical substances and compositions, allowing to treat and prevent the unsightly effects of polluting agents on human skin, on the scalp and on hair. Said chemical substances and compositions can act according to different approaches: -by protecting the skin mechanically, that is to say by isolating it from polluting agents or, more realistically,by limiting its exposure to said polluting agents by applying a "barrier" material to the skin, for example a topical composition having a film-forming effect. -by protecting the skin chemically, that is to say by applying to the skin one or more chemical substances or compositions which act as a chemical barrier, such as for example chemical substances or compositions having antioxidant properties, which complement the action of the antioxidant defenses intrinsically present on the skin, and / or heavy metal chelating properties, which are capable of capturing and trapping said polluting agents, and more particularly heavy metals, and consequently reducing or eliminating the oxidative effect of said polluting agents on the skin. -by protecting the skin biologically,that is to say by applying to the skin one or more chemical substances or compositions which act on the cells of the epidermis of the skin to increase their capacity to reduce or eliminate the harmful effects of polluting agents, such as for example reducing or eliminating the oxidative or inflammatory effects of said polluting agents. The European patent application published under number EP 3527264A1 discloses hair care compositions combining shea butter, carnauba wax, caprylic / capric triglycerides, an acid hydrolyzate of proteins, stearamidopropyl dimethylamine, an algae extract, in particular Alaria esculenta and xylitylglucoside. This patent application describes the use of such a composition for the care and maintenance of dry hair, babies' or children's hair, or even Afro-mixed hair. There is no mention anywhere of a use of the composition,nor brown algae extract and more particularly an extract of the species Alaria esculenta to prevent the harmful effects of pollution on the scalp. As part of their research into new cosmetic active ingredients for preventing the harmful effects of indoor or outdoor air pollutants on the scalp, the inventors have sought to develop a new technical solution based on the use of an extract of the brown algae Alaria Esculenta to protect the scalp against the harmful effects of indoor or outdoor air pollutants. According to a first aspect, the invention relates to the cosmetic use of an extract of the brown algae Alaria Esculenta, as a cosmetic active ingredient for protecting the scalp against the harmful effects of indoor or outdoor air pollutants,in particular against any changes in the external appearance of the scalp due to indoor or outdoor atmospheric pollutants, said pollutants being chosen from: toxic gases such as sulfur, sulfur dioxide and ozone; heavy metals such as cobalt, mercury, cadmium, lead and nickel; noble metals such as rhodium, platinum and palladium; volatile organic compounds (or VOCs); tobacco smoke such as cigarette smoke and / or dust. According to a more particular aspect of the present invention, by "cosmetic use" of an extract of the brown algae Alaria Esculenta, is meant an administration of an effective amount of said extract topically either directly or via a composition for topical use comprising it. For the purposes of the present invention, by "the harmful effects" of indoor or outdoor atmospheric pollutants,unsightly sensations or manifestations are understood to mean, in particular visible sensations or manifestations of irritation and / or inflammation of the scalp, such as for example itching, tingling, redness, burning, tingling, heating, tightness, or any changes in the external appearance of the scalp, caused by indoor or outdoor air pollutants mentioned above. In particular, said changes in the external appearance of the scalp are chosen from itching, tingling, redness, burning, tingling, heating, tightness and / or a mixture of these manifestations. According to a more particular aspect of the present invention, the indoor or outdoor air pollutants are chosen from heavy metals such as cobalt, mercury, cadmium, lead and nickel and / or noble metals such as rhodium,platinum and / or palladium. According to a more particular aspect of the present invention, said extract is prepared by methods known to those skilled in the art. It is more particularly prepared according to a process comprising the following successive steps: The extract of the species Alaria esculenta, the use of which is the subject of the present invention, is an extract obtained by the process comprising the following essential steps: - harvesting of the brown algae Alaria esculenta in the open sea - drying of the previously harvested brown algae Alaria esculenta - grinding of the previously harvested and dried brown algae Alaria esculenta - maceration of the previously harvested, dried and ground brown algae Alaria esculenta in a hydroglycolic solvent (Water: 1,3 butanediol) at a temperature between 15°C and 35°C for a period between 1h and 8h. The hydroglycolic solvent consists of 100% of its own mass of 48% to 52% water and 48% to 52% butylene glycol,- Two successive filtrations, the second of which is carried out on a filter with an average pore diameter of 0.2 µm to obtain a liquid extract, − whose dry extract, expressed in % by mass, is between 0.5% and 2.5% and the mass content of the hydroglycolic solvent is between 97.5% and 99.5% by mass, − whose pH value is greater than or equal to 5.5 and less than 7.5, measured at a temperature of 20°C. The present invention also relates to a cosmetic composition, in particular for topical use, comprising as active ingredient an effective amount of an extract of the brown algae Alaria Esculenta and at least one cosmetically acceptable ingredient. 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 scalp, whether by direct application or indirect application when said composition is incorporated, for example, in the case of a scalp care product in the form of a lotion, a cream, a milk, an aqueous gel, an oily gel, and impregnated on a support which is intended to be in contact with the scalp (paper, wipe, textile, transdermal device, etc.). By "effective quantity" of the extract of the brown algae Alaria Esculenta, we mean a sufficient quantity which allows the scalp to be protected against the harmful effects, as described above, of indoor or outdoor atmospheric pollutants, as defined above, more particularly heavy metals such as cobalt, mercury, cadmium, lead and nickel, and / or noble metals such as rhodium,platinum and palladium. According to a more particular aspect of the present invention, said cosmetic composition comprises, 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 2.5% by mass, and even more particularly between 0.5% and 2% by mass of said extract as active ingredient.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: - from 0.05% to 5% by mass of the extract of brown algae Alaria Esculenta as defined above, and - from 95% to 99.95% by mass of at least one cosmetically acceptable ingredient.More particularly, the cosmetic composition which is the subject of the present invention comprises, for 100% of its mass: - 0.5% to 2.5% by mass, in particular 0.5% by mass of the extract of the brown algae Alaria Esculenta as defined above, and- 97,5% to 99.5% by mass, in particular 99.5% by mass, of at least one cosmetically acceptable ingredient. More particularly, the cosmetic composition which is the subject of the present invention comprises for 100% of its mass: -1% by mass of the extract of the brown algae Alaria Esculenta as defined above, and- 99% by mass of at least one cosmetically acceptable ingredient. In particular, the cosmetic composition which is the subject of the present invention comprises for 100% of its mass: -2% by mass of the extract of the brown algae Alaria Esculenta as defined above, and- 98% by mass of at least one cosmetically acceptable ingredient. The present invention also relates to the use of said cosmetic composition for protecting the scalp against the harmful effects of indoor or outdoor atmospheric pollutants, in particular against any changes in the external appearance of the scalp due to indoor or outdoor atmospheric pollutants,said pollutants being chosen from: toxic gases such as sulfur, sulfur dioxide and ozone; heavy metals such as cobalt, mercury, cadmium, lead and nickel; noble metals such as rhodium, platinum and palladium; volatile organic compounds (or VOCs); tobacco smoke such as cigarette smoke and / or dust. The cosmetic composition according to the invention is in particular intended to protect the scalp against the harmful effects of heavy metals such as cobalt, mercury, cadmium, lead and nickel, and / or noble metals such as rhodium, platinum and palladium. 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 or oil-in-water type,water-in-oil-in-water or oil-in-water-in-oil, or in the form of a powder. 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 provided with a perforated wall such as a grid or in a device provided with a ball applicator (or also called "roll-on"). 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. The expression "cosmetically acceptable" used in the definition of the cosmetic formulation for topical use means, according to the Directive of the Council of the European Economic Community No. 76 / 768 / EEC of July 27, 1976, amended by Directive No. 93 / 35 / EEC of June 14, 1993,that said formulation comprises 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 odors and / or protecting them or maintaining them in good condition. In general, the extract of the brown algae Alaria Esculenta 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, antioxidant agents, perfumes, essential oils, preservatives, conditioning agents, deodorant agents, whitening agents intended for bleaching hair and skin, active ingredients intended to provide a treating and / or protective action with respect to the skin or hair, sunscreens, 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. As examples of foaming and / or detergent surfactants which can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above,we can cite foaming surfactants and / or anionic, cationic, amphoteric or non-ionic detergents. 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,of N-acylated derivatives of peptides, of N-acylated derivatives of proteins, of N-acylated derivatives of fatty acids. Among the foaming and / or detergent amphoteric surfactants, mention may be made of alkylbetaines, alkylamidobetaines, sultaines, alkylamidoalkylsulfobetaines, imidazoline derivatives, phosphobetaines, amphopolyacetates and amphopropionates. Among the foaming and / or detergent cationic surfactants which may 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. Among the foaming and / or detergent non-ionic 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 more particularly of alkylpolyglycosides comprising a linear or branched, saturated or unsaturated aliphatic radical,and containing 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; copra amides; N-alkylamines. As examples of thickening and / or gelling 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 of fatty esters of alkylpolyglycosides, optionally alkoxylated,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. As examples of thickening and / or gelling agents 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 of polyelectrolyte type polymers, linear or branched or crosslinked,such as homopolymer of partially or fully salified acrylic acid, homopolymer of partially or fully salified methacrylic acid, homopolymer of partially or fully salified 2-methyl-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid (AMPS), copolymers of acrylic acid and AMPS, copolymers of acrylamide and AMPS, copolymers of vinylpyrrolidone and AMPS, copolymers of AMPS and (2-hydroxyethyl)acrylate, copolymers of AMPS and (2-hydroxyethyl)methacrylate, copolymers of AMPS and hydroxyethylacrylamide, copolymers of AMPS and N,N-dimethylacrylamide, copolymers of AMPS and tris(hydroxy-methyl)acrylamido 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-dimethyl acrylamide, 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 one and less than or equal to fifty. 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 presented in the form of a solution,of 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, SEPILIFETM NUDE, ARISTOFLEX™AVC, ARISTOFLEX™AVS, ARISTOFLEX™AVL, ARISTOFLEX™BLV, ARISTOFLEX™Silk, 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. As examples of thickening and / or gelling agents that 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 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 originating from cassia gum (DS = 1 / 5), locust bean gum (DS = 1 / 4), tara gum (DS = 1 / 3), guar (DS = 1 / 2), fenugreek gum (DS = 1). As examples of thickening and / or gelling agents that can be combined with brown algae extract in the cosmetic composition,subject of the present invention as defined above, mention may be made of 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. Mention may also be made of cellulose, cellulose derivatives such as methylcellulose, ethylcellulose, hydroxypropylcellulose, silicates, starch, hydrophilic derivatives of starch, polyurethanes. As examples of stabilizing agents 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 microcrystalline waxes, and more particularly ozokerite,mineral salts such as sodium chloride or magnesium chloride, silicone polymers such as polysiloxane polyalkyl polyether copolymers. 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. As examples of thermal or mineral waters which can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above,Examples of hydrotropic agents that can be combined with the brown algae extract in the cosmetic composition, which is the subject of the present invention, are: as defined above, we can cite xylenes sulfonates, cumenes sulfonates, hexylpolyglucoside, 2-ethylhexylpolyglucoside, n-heptyl polyglucoside. As examples of emulsifying surfactants that can be combined with the brown algae extract in the cosmetic composition,subject of the present invention as defined above, non-ionic surfactants, anionic surfactants and cationic surfactants may be mentioned. As examples of emulsifying non-ionic surfactants which may be combined with the brown algae extract in the cosmetic composition, subject of the present invention as defined above, mention may be made of 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 between 5 moles and 150 moles of ethylene oxide,such as the composition comprising ethoxylated stearic acid with 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 polyglucoside, 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, FLUIDANOV™20X and EASYNOV™. Examples of emulsifying anionic 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 glyceryl stearate citrate, cetearyl sulfate, soaps such as sodium stearate or triethanolammonium stearate, N-acylated derivatives of salified amino acids, for example stearoyl glutamate. Examples of emulsifying cationic 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 amine oxides,quaternium-82 and the surfactants described in patent application WO96 / 00719 and mainly those whose fatty chain comprises at least 16 carbon atoms. As examples of opacifying and / or pearlescent agents 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 sodium palmitate, sodium stearate, sodium hydroxystearate, magnesium palmitate, magnesium stearate, magnesium hydroxystearate, ethylene glycol monostearate, ethylene glycol distearate, polyethylene glycol monostearate, polyethylene glycol distearate, fatty alcohols comprising from 12 to 22 carbon atoms. As examples of texturizing agents 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 of 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. 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 metal 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 glycol chlorohydrate 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,the complex of aluminum sesquichlorohydrate and polyethylene glycol. Examples of oils that can be combined with the brown algae extract in the cosmetic composition, the subject of the present invention as defined above, include the following compounds: - Linear alkanes containing 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; - 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 cited 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;- Cycloalkanes optionally substituted by one or more linear or branched alkyl radicals;- Mineral white oils, such as those marketed under the following names:- Marcol™52, Marcol™82, Drakeol™6VR, Eolane™130, Eolane™150;- Hemisqualane (or 2,6,10-trimethyl-dodecane; CAS number: 3891-98-3), lesqualane (or 2,6,10,15,19,23-hexamethyltetracosane), hydrogenated polyisobutene or hydrogenated polydecene;- Mixtures of alkanes containing from 15 to 19 carbon atoms, said alkanes being linear alkanes, branched alkanes and cycloalkanes, and more particularly the mixture (M1) 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;- 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 that marketed under the brand name Vegelight™ 12-14;- Fatty alcohol ethers of formula (II):- 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;- Monoesters of fatty acids and alcohols of formula (III):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, 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, 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;- Di-esters of fatty acids and glycerol of formula (IV) and formula (V): R'3-(C=O)-O-CH2-CH(OH)-CH2-O-(C=O)-R'4 (IV) 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 a linear or branched, saturated or unsaturated acyl group containing from eight to twenty-four carbon atoms;- Tri-esters of fatty acids and glycerol of formula (VI): 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 a linear or branched, saturated or unsaturated acyl group containing from eight to twenty-four carbon atoms;- Vegetable oils, such as phytosqualane, sweet almond oil, decoprah 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 oil, oils derived from flowers or vegetables; -Ethoxylated vegetable oils. In this application, the term "oils" means compounds and / or mixtures of compounds that are insoluble in water and present in a liquid form at a temperature of 25°C. Examples of waxes that can be combined with the brown algae extract in the cosmetic composition, 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 solid at room temperature; glycerides solid at room temperature. By "waxes" is meant in the present application the compounds and / or mixtures of compounds insoluble in water, appearing in a solid form at a temperature greater than or equal to 45°C. As examples of active ingredients 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 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 B10 (niacinamide and its derivatives); compounds showing a skin lightening or depigmenting action such as ω-undecelynoyl phenylalanine marketed under the name SEPIWHITE™MSH, SEPICALM™VG, the monoester and / or diester of glycerol of ω-undecelynoyl phenylalanine, ω-undecelynoyl dipeptides, arbutin, kojic acid, hydroquinone; compounds showing a soothing action including 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, e.g. Raffermine™; wheat extracts e.g. TENSINE™ or GLIADINE™; plant extracts, such as tannin-rich plant extracts, isoflavone-rich plant extracts or terpene-rich plant extracts; freshwater or marine algae extracts; marine plant extracts; marine extracts in general such as corals; essential waxes; bacterial extracts; ceramides; phospholipids; compounds showing an antimicrobial action or a purifying action, such as LIPACIDE™ C8G, LIPACIDE™ 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 protecting the integrity of the dermo-epidermal junction; active ingredients increasing the synthesis of components of the extracellular matrix such as collagen, elastins, glycosaminoglycans; active ingredients acting favorably on chemical cellular communication such as cytokines or physical ones such as integrins; active ingredients creating a sensation of "heating" on the skin such as activators of cutaneous microcirculation (such as nicotinic acid derivatives) or products creating a sensation of "coolness" on the skin (such as menthol and derivatives); active ingredients improving skin microcirculation,for example veinotonics; draining active ingredients; decongestant active ingredients such as extracts of ginko biloba, ivy, horse chestnut, bamboo, ruscus, butcher's broom, centalla asiatica, fucus, rosemary, willow; skin tanning or browning agents, for example dihydroxyacetone (DHA), erythrulose, mesotartaric aldehyde, glutaraldehyde, glyceraldehyde, alloxan, ninhydrin, plant extracts for example extracts of red woods of the genus Pterocarpus and of 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 0971683; 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 carotenoids (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, glyceryloleate, 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 for 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 that mimic the activity of DOPAchrome tautomerase chosen from those described in the European patent application published under number EP 1515688 A2, synthetic molecules that mimic 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 1515688 A2. Examples of probiotics that can be combined with brown algae extract in cosmetic compositions include:object of the present invention as defined above, mention may be made of 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 associated with a solid support, for example calcium carbonate, dextrose or sorbitol. As examples of antioxidant agents which may be associated with the brown algae extract in the cosmetic composition, object of the present invention as defined above, mention may be made of EDTA and its salts, citric acid, tartaric acid, oxalic acid, BHA (butylhydroxyanisole), BHT (butylhydroxytoluene), tocopherol derivatives such as tocopheryl acetate,mixtures of antioxidant compounds such as DISSOLVINETM GL 47S marketed by Akzo Nobel under the INCI name: Tetrasodium Glutamate Diacetate. 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. 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, include 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,N-dimethyl PABA; 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, 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-α-cyano-β-phenyl cinnamate, 2-ethylhexyl-α-cyano-β-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-1'-oxy)-1,3,5-triazine, 4,4-((6-(((1,1-dimethylethyl)amino)carbonyl)phenyl)amino)-1,3,5-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-norbornylidene)-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. 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, we can cite titanium oxides, zinc oxides, cerium oxide, zirconium oxide, yellow, red or black iron oxides, chromium oxides. These mineral screens can be micronized or not,having undergone surface treatments or not and optionally being presented in the form of aqueous or oily pre-dispersions. The present invention also relates to a cosmetic care method for protecting the scalp against the harmful effects of indoor or outdoor atmospheric pollutants, in particular against any changes in the external appearance of the scalp due to indoor or outdoor atmospheric pollutants as described above, comprising the application to the scalp of the cosmetic composition as defined above. The present invention also relates to an extract of the brown algae Alaria Esculenta for its use in the prevention of a scalp disorder chosen from the group consisting of: urticaria, eczematous dermatitis, rosacea, psoriasis, herpes, photodermatoses, atopic dermatitis, contact dermatitis, lichen, prurigos, pruritic diseases, fibrosis,collagen maturation disorders, scleroderma, eczema, cysts, seborrheic dermatitis, lichen planus, frontal alopecia, fibrosing alopecia, discoid lupus erythematosus, trichodynia, telogen effluvium, and actinic keratosis. According to a more particular aspect of the present invention, the extract of the brown algae AlariaEsculenta is in a form suitable for topical administration. The present invention also relates to a pharmaceutical composition comprising an effective amount of an extract of the brown algae Alaria Esculenta as active ingredient and at least one pharmaceutically acceptable ingredient for use in the prevention of a scalp disorder. Said scalp disorder is selected from the group consisting of: urticaria, eczematous dermatitis, rosacea, psoriasis, herpes, photodermatoses, atopic dermatitis, contact dermatitis, lichen, prurigos,pruritic diseases, fibrosis, collagen maturation disorders, scleroderma, eczema, cysts, seborrheic dermatitis, lichen planus, frontal alopecia, fibrosing alopecia, discoid lupus erythematosus, trichodynia, telogen effluvium, and actinic keratosis. The effective amount of an extract of the brown algae Alaria Esculenta included in the pharmaceutical composition makes it possible to prevent scalp disorders as defined above, when the scalp is exposed to indoor or outdoor atmospheric pollutants as defined above, more particularly heavy metals such as cobalt, mercury, cadmium, lead and nickel, and / or noble metals such as rhodium, platinum and palladium. According to a more particular aspect of the present invention,said pharmaceutical composition comprises for 100% by mass: - from 2% by mass to 30% by mass of the extract of brown algae Alaria Esculenta as defined above and - from 70% by mass to 98% by mass of at least one pharmaceutically acceptable technological additive. According to a more particular aspect of the present invention, said pharmaceutical composition comprises for 100% by mass: - from 3% by mass to 30% by mass of the extract of brown algae Alaria Esculenta as defined above and - from 70% by mass to 97% by mass of at least one pharmaceutically acceptable technological additive. According to a more particular aspect of the present invention, said pharmaceutical composition comprises for 100% by mass: - from 5% by mass to 30% by mass of the extract of brown algae Alaria Esculenta as defined above and - from 70% by mass to 95% by mass of at least one pharmaceutically acceptable technological additive. According to a more particular aspect of the present invention,said pharmaceutical composition comprises for 100% by mass: - from 10% by mass to 30% by mass of the extract of brown algae Alaria Esculenta as defined above and - from 70% by mass to 90% by mass of at least one pharmaceutically acceptable technological additive. In the context of the invention, the pharmaceutically acceptable ingredient is a technological additive usually used in the field of formulations for topical use. By "technological additive" is meant any pharmaceutically acceptable ingredient or any chemical substance or any chemical composition whose technical function is to allow and / or facilitate the mixing of the different constituents of said pharmaceutical composition, to facilitate and / or optimize the physical properties of said pharmaceutical composition, as well as to facilitate and / or optimize its flow, its stability, and its incorporation into a pharmaceutical formulation,and which are likely to comply with the conditions required by the regulations in force for the marketing of a pharmaceutical formulation. The pharmaceutical composition for topical use as defined above may further comprise one or more technological additives chosen from solvents and co-solvents, agents for improving skin penetration. Examples of solvents and co-solvents possibly present in the pharmaceutical compositions for topical use which are the subject of the present invention include water, organic solvents, for example glycerol, diglycerol, glycerol oligomers, ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, diethylene glycol, xylitol, erythritol, sorbitol, water-soluble alcohols such as ethanol, isopropanol or butanol, mixtures of water and said organic solvents, propylene carbonate, ethyl acetate,benzyl alcohol. Examples of skin penetration enhancing agents that may be present in the pharmaceutical compositions for topical use that are the subject of the present invention include glycol ethers such as, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol mono-n-butyl ether, diethylene glycol monoether (or Transcutol-p), fatty acids such as oleic acid, fatty acid glycerol esters such as, for example, glycerol behenate, glycerol palmitostearate, behenoyl macroglycerides, polyoxyethylene-2-stearyl ether, polyoxyethylene-2-oleyl ethers, terpenes such as D-Limonene,essential oils such as, for example, eucalyptus essential oil. In general, the pharmaceutical composition according to the invention may comprise excipients and / or active ingredients usually used in the field of formulations for topical use, in particular pharmaceutical or dermopharmaceutical. Examples of active agents that can be combined with the composition according to the invention include substances or compositions that provide a beneficial effect to the human subject. These active agents may be, for example, antibodies, analgesics, anti-inflammatories, cytokines, cytoxins, growth factors, hormones, lipids, oligonucleotides, polymers, polysaccharides, polypeptides, protease inhibitors, vitamins, insect repellents, antibiotics,anti-fungal agents. Examples of analgesic and anti-inflammatory agents that can be combined with the composition according to the invention include acetaminophen, aspirin, salicylic acid, methyl salicylate, choline salicylate, glycol salicylate, 1-menthol, camphor, mefenamic acid, fluphenamic acid, indomethacin, protizidic acid, fentiazac, tolmetin, tiaprofenic acid, phenylbutazone, oxyphenbutazone, clofezone, pentazocine, mepirizole, hydrocortisone, cortisone, dexamethasone, fluocinolone, triamcinolone, medrysone, prednisolone, flurandrenolide, prednisone, halcinonide, methylprednisolone, fludrocortisone, corticosterone, paramethasone, betamethasone. Examples of antiseptic agents that can be combined with the pharmaceutical composition according to the invention include cetrimide, povidone-iodine, chlorhexidine, iodine, benzalkonium chloride,benzoic acid, nitrofurazone, benzoyl peroxide, hydrogen peroxide, hexachlorophene, phenol, resorcinol and cetylpyridinium chloride. Examples of anti-insecticide agents that can be combined with the pharmaceutical composition according to the invention include trichiorfon, triflumerone, fenthion, bendiocarb, cyromazine, dislubenzurone, dicyclanil, fluazurone, amitraz, deltamethrin, cypermethrin, chlorfenbinphose, flumethrin, ivermectin, abermectin, avermectin, doramectin, moxidectin, zeti-cypermethrin, diazinone, spinosad, imidacloprid, nitenpyran, pyriproxysene, sipronil, cythioate, lufenurone, selamectin, milbemycin oxime, chlorpyrifose, coumaphose, propetamphose, alpha-cypermethrin, highciscypermethrin, ivermectin, diflubenzurone, cyclodiene,carbamate and benzoyl urea. Examples of antimicrobial agents that can be combined with the pharmaceutical composition according to the invention include sulfonamides, aminoglycosides such as neomycin, tobramycin, gentamycin, amikacin, kanamycin, lespectinomycin, paromomycin, netilmicin, polypeptides, cephalosporins, oxazolidinones such as ciprofloxacin, levofloxacin, ofloxacin. Examples of active agents that can be combined with the pharmaceutical composition according to the invention include vitamin E, Coenzyme Q.10, L-carnitine, choline, folic acid, magnesium and its salts, caprylic acid, linoleic acid, lauric acid, taurine, vitamin C, vitamin A, and B vitamins. Bibliographic references [1] Drakaki E, Dessinioti C, Antoniou CV. Air pollution and the skin. Frontiers in Environmental Science, 2014, 2,1-6. [2] Mancebo SE and Wang SQ. Recognizing the impact of ambient air pollution on skinhealth. Journal of European Academy of Dermatology and Venerology, 2015, 29, 2326-2332.[3] Magnani ND, Muresan XM, Belmonte G, Cervellati F, Sticozzi C, Pecorelli A, Miracco C, Marchini T, Evelson P, Valacchi G. Skin Damage Mechanisms Related to Airborne Particulate Matter Exposure. Toxicological Sciences, 2016, 149, 227-236. [4] Valacchi G, Sticozzi C, Pecorelli A, Cervellati F, Cervellati C, Maioli E. Cutaneousresponses to environmental stressors. Annals of the New York Academy of Sciences, 2012,1271, 75-8.1 [5] Ushio H, Nohara K, Fujimaki H. Effect of environmental pollutants on the production of pro-inflammatory cytokines by normal human dermal keratinocytes. Toxicology Letters, 1999, 105,17-24. The following example illustrates the invention without limiting it. Evaluation of the preventive effects of the harmful effects of exposure to cadmium on a culture of hair follicle keratinocytes. Protocol: Hair follicle keratinocytes are cultured in 96-well culture plates coated with poly-L-lysine (6.4µg / mL). After three days of culture, the products evaluated, namely Extract A at 0.5% by mass and sulforaphane (a positive reference known to those skilled in the art), are applied to the culture medium. After a 24-hour incubation, the cells are exposed to a 30µM cadmium solution for 24 hours, then 24 hours later, an assay for IL-1α production is performed. The results are normalized vs. the amount of protein (BCA assay). The Extract (A) that was evaluated is a product marketed under the brand name AlarianeTM CV and which was obtained by maceration of the brown algae Alaria esculenta,previously harvested in the open sea then dried, crushed and macerated in a hydroglycolic solvent (Water: 1,3 butanediol) at a temperature between 15°C and 35°C for a period between 1h and 8h. The hydroglycolic solvent consists of 100% of its own mass of 48% to 52% water and 48% to 52% butylene glycol. This maceration phase was followed by at least 2 successive filtrations including a final filtration of 0.2 µm to obtain a liquid extract (Extract A) whose characteristics are as follows: - Clear liquid of yellow to brown color and with the characteristic odor of an algae extract - pH greater than or equal to 5.5 and less than or equal to 7.5 - Dry extract of 2%; the mass content of the hydroglycolic solvent is 98% by mass. Statistical elements: The experiments were carried out in 4 replicates. The values ​​obtained are expressed as means + / - SD (standard deviation). For each condition,a percentage effect was calculated: X: condition studied Control condition: cells treated with cadmium A percentage of protection is also calculated: The statistical analysis was carried out by a Student test and a significance threshold set at 5%, comparing the conditions two by two. A difference between the effectiveness of two conditions was considered: -Significant if p < 0.05;- Said to be "at the limit of significance" if 0.05 ≤ p < 0.1;- And not significant if p > 0.1.Results: IL-1α (pg / ng of proteins) Average, % Effet %Protection Tested conditions ± SD Untreated cells 0.38 - -± 0.01 Cells treated with Cadmium (30µM) 2.42+541%*** - ± 0.34 vs untreated Cells treated with+ Sulforaphane1.14-53%** 63%**Cadmium (30µM) (1µM) ± 0.14 +Extract A (0.5%) 1.77 -27%* 32%*± 0.26 Protection against the secretion of the cytokine IL-1α following the application of a pollutant stress carried out with cadmium *:p<0.05; **:p<0.01; ***:p<0.001 As expected, cadmium significantly stimulates IL-1α production by hair follicle keratinocytes (+541%, p<0.001). Sulforaphane, used as a positive reference in this model, protects hair follicle keratinocytes from cadmium-induced stress (63%, p<0.01). Extract A, tested at 0.5%, significantly protects cells from cadmium-induced stress by 32% ( p<0.05). Conclusion: Under the experimental conditions tested, extract A protects hair follicle keratinocytes from cadmium-induced inflammation.

Claims

Claims [Revendication 1] Utilisation cosmétique d’un extrait de l’algue brune Alaria Esculenta comme actif cosmétique pour prévenir le cuir chevelu contre toutes modifications de l'aspect extérieur du cuir chevelu dues aux polluants atmosphériques intérieurs ou extérieurs, lesdits pollutants being chosen from: - les gaz toxiques tels que le soufre, le dioxyde de soufre et l’ozone, - les métaux lourds tels que le cobalt, le mercure, le cadmium, le plomb et le nickel, - les métaux nobles tels que le rhodium, le platine et le palladium, - les composés organiques volatils (ou C.O.V.), - la fumée de tabac comme la fumée de cigarettes, et - des poussières. [Revendication 2] Utilisation selon la revendication 1, caractérisée en ce que les polluants indoor or outdoor atmospheric agents are chosen from heavy metals such as cobalt, le mercure, le cadmium, le plomb et le nickel et / ou les métaux nobles tels que le rhodium, le platine et le palladium. [Revendication 3] Composition cosmétique comprenant pour 100% massique, entre 0,5% massique et 2,5% massique d’un extrait de l’algue brune Alaria Esculenta en tant que active ingredient and at least one cosmetically acceptable ingredient. [Revendication 4] Utilisation de la composition selon la revendication 3 pour prévenir le scalp against any changes in the external appearance of the scalp due to indoor or outdoor atmospheric pollutants, said pollutants being chosen from - les gaz toxiques tels que le soufre, le dioxyde de soufre et l’ozone, - les métaux lourds tels que le cobalt, le mercure, le cadmium, le plomb et le nickel, - les métaux nobles tels que le rhodium, le platine et le palladium, - les composés organiques volatils (ou C.O.V.), - la fumée de tabac comme la fumée de cigarettes, et - des poussières. [Revendication 5] Procédé de soin cosmétique pour prévenir le cuir chevelu contre toutes modifications de l'aspect extérieur du cuir chevelu dues aux polluants atmosphériques indoor or outdoor, said pollutants being chosen from: - les gaz toxiques tels que le soufre, le dioxyde de soufre et l’ozone, - les métaux lourds tels que le cobalt, le mercure, le cadmium, le plomb et le nickel, - les métaux nobles tels que le rhodium, le platine et le palladium, - les composés organiques volatils (ou C.O.V.), - la fumée de tabac comme la fumée de cigarette, et - des poussières, said method comprising applying to the scalp the composition according to claim 3. [Revendication 6] Extrait de l’algue brune Alaria Esculenta pour son utilisation dans laprevention of a scalp disorder, selected from urticaria, eczematous dermatitis, rosacea, psoriasis, herpes, photodermatoses, atopic dermatitis, contact dermatitis, lichen, prurigos, pruritic diseases, fibrosis, collagen maturation disorders, scleroderma, eczema, cysts, seborrheic dermatitis, lichen planus, frontal alopecia, fibrosing alopecia, discoid lupus erythematosus, trichodynia, telogen effluvium, and actinic keratosis. [Revendication 7] Extrait de l’algue brune Alaria Esculenta selon la revendication 6, characterized in that it is in a form suitable for topical administration. [Revendication 8] Composition pharmaceutique comprenant pour 100% de massique, de 3% massique à 30% massique d’un extrait de l’algue brune Alaria Esculenta en tant que active ingredient and from 70% by mass to 97% by mass of at least one pharmaceutically acceptable ingredient for use in the prevention of a scalp disorder.