USE IN COSMETICS OF AN EXTRACT FROM AN ALGAE OF THE GENUS LAMINARIA FOR THE PROTECTION OF HAIR AGAINST OXIDATIVE DAMAGE INDUCED BY DIFFERENT STRESSES.

Abstract

COSMETIC USE OF AN EXTRACT FROM AN ALGAE OF THE GENUS LAMINARIA FOR PROTECTING HAIR AGAINST OXIDATIVE DAMAGE INDUCED BY VARIOUS STRESS. The present invention relates to the cosmetic use of a liposoluble extract from a laminaria algae for protecting hair against damage induced by exposure to oxidative stress, or repairing it after such exposure. In particular, the invention relates to the use of such an extract for protecting hair during heat treatment, chemical coloring, perming, exposure to UV rays, atmospheric pollutants, salt or chlorine.

Description

Title of the invention: USE IN COSMETICS OF AN EXTRACT FROM AN ALGAE OF THE GENUS LAMINARIA FOR THE PROTECTION OF HAIR AGAINST OXIDATIVE DAMAGE INDUCED BY DIFFERENT STRESS.

[0001] CONTEXT OF THE INVENTION

[0002] The present invention relates to a novel cosmetic active ingredient for hair care for protecting hair against oxidative damage induced by multiple stresses including common cosmetic procedures such as frequent washing, chemical treatments, such as coloring based on oxidation reactions, heat treatments, such as the use of straightening irons, curling irons, and hair dryers or environmental stresses including exposure to UV, pollutants, salt or chlorine.

[0003] DESCRIPTION OF THE PRIOR ART

[0004] Reminders about hair

[0005] Hair plays a significant role in the expression of individual and cultural identity, strongly influencing self-esteem and social perception.

[0006] Beyond its biological function of protection against external elements, hair contributes to personal aesthetics, often reflecting general health, lifestyle, and personal choices in fashion and personal care.

[0007] The hair shaft, or hair fiber, is a complex structure mainly composed of keratins, that is to say proteins rich in sulfur which give the hair strength and elasticity.

[0008] The hair shaft is organized into three main concentric layers: the cuticle, the cortex, and in some cases, the medulla located in its center.

[0009] The cuticle, the outer layer of the shaft, is formed of dead, comified, flat and superimposed cells which protect the cortex, the most voluminous part of the hair where keratins are mainly found organized in the form of fibrils. This architecture is essential to the resistance and integrity of the hair shaft.

[0010] However, the hair fiber is subject to numerous external stresses that can compromise its integrity. Among the most frequent attacks are repeated washing, mechanical stress, chemical treatments including oxidation coloring, heat treatments, such as the use of hair dryers, straighteners or sulkers, environmental factors, including UV rays, air pollutants, salt, chlorine.

[0011] These procedures cause significant oxidative damage to keratins, compromising the integrity of the hair structure. While healthy hair is characterized by compact and smooth cuticles, their alteration leads to their detachment increasing the porosity of the hair, making the hair fiber more permeable and vulnerable to humidity and other forms of environmental stress.

[0012] These microscopic changes translate into visual impacts. Hair becomes dry, frizzy, fragile, and brittle, with split ends and increased difficulty in styling.

[0013] In addition, the degradation of the hair surface leads to a reduction in the reflection of light, which manifests itself in dull hair characterized by a lack of shine.

[0014] At the molecular level, the loss of hair integrity is mainly due to the oxidation of the proteins that constitute it, in particular keratins.

[0015] This oxidation causes chemical changes within the protein structure of the hair, a phenomenon also known as carbonylation.

[0016] Carbonylation corresponds to the fixation of carbonyl derivatives in proteins, leading to an alteration of their physicochemical properties at the origin of changes in their structures, their interactions and consequently their functions.

[0017] This modification of hair proteins reduces their ability to maintain the structural integrity and resilience of the hair.

[0018] Chemical treatments such as oxidation dyes, as well as exposure to other stresses including high heat sources, UV rays, pollutants, are key factors that promote this type of carbonylation reactions.

[0019] For example, considered one of the most aggressive stresses for hair, oxidative coloring involves a process where, to allow the penetration of dyes deep into the cortex of the hair shaft, a forced opening of the cuticles is necessary. This mechanism, while essential for the effectiveness of coloring, exposes the hair to increased vulnerability, accompanied by a significant increase in the carbonylation of hair shaft proteins.

[0020] Consequently, carbonylation of hair fiber proteins is an indicator of severe oxidative damage, highlighting the importance of protecting hair from the stresses it undergoes to preserve its health and aesthetics.

[0021] The use of antioxidants in hair care formulations represents a key strategy to counter this process, providing protection against carbonylation and helping to maintain the integrity of the hair's protein structure.

[0022] Together, these effects impair not only hair health, but also hair aesthetics, highlighting the importance of effective protective solutions in hair care formulations aimed at preserving hair from oxidative damage induced by the various stresses to which it is constantly subjected: mechanical, chemical, thermal, environmental stress.

[0023] OBJECTS OF THE INVENTION

[0024] The multiple treatments and environmental stresses to which the hair is subjected generate oxidative damage with significant consequences on its quality and beauty.

[0025] Thus, the search for natural and environmentally friendly preventive and / or restorative solutions to limit this damage appears essential to preserve the aesthetics of the hair. These solutions must also meet the demands of consumers who are looking for products that meet contemporary ecological challenges, i.e. products of natural origin.

[0026] The object of the present invention is to meet these needs by proposing a new active ingredient making it possible to protect the hair against oxidative damage linked to different sources of stress.

[0027] In particular, the object of the present invention is to propose a new active ingredient making it possible to limit the oxidation or carbonylation of the proteins of the hair shaft, to limit the excessive porosity of the hair and its roughness due to excessive detachment of the cuticles being the origin of its fragility, its rough appearance, its dull appearance and frizz.

[0028] In particular, the invention aims to provide such an active ingredient which has the aforementioned advantages while not preventing coloring or a permanent from being carried out.

[0029] It is with this in mind that the applicant company carried out research and demonstrated that an extract obtained from an algae of the genus Laminaria, in particular Laminaria ochroleuca, made it possible to meet the objectives of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention is based on the unexpected discovery that a liposoluble extract of phaeophyceae of the genus Laminaria has remarkable preventive and protective properties for the hair shaft with respect to the multiple factors to which the hair is subjected: repeated washing, chemical or thermal treatments, environmental factors including exposure to UV radiation, atmospheric pollutants, salt or even chlorine.

[0031] This extract acts effectively by reducing excessive porosity, the cause of increased permeability of the hair leading to problems such as frizz.

[0032] In addition, it reduces the roughness of the hair shaft, characterized by the lifting of the cuticles, thus preventing the tendency towards a rough, dull appearance and brittleness of the hair.

[0033] This effectiveness comes from its ability to modulate one of the fundamental mechanisms at the origin of these deteriorations, namely oxidative damage to keratins, the major constituent proteins of the hair shaft.

[0034] Thus, the invention relates to the cosmetic use of a liposoluble extract from an algae of the genus Laminaria for the protection of hair against damage induced by exposure to oxidative stress, or their repair after such exposure.

[0035] In particular, the invention relates to the cosmetic use of a liposoluble extract from an algae of the genus Laminaria for the protection of hair during heat treatment, chemical coloring, permanent wave, exposure to UV, atmospheric pollutants, salt or chlorine.

[0036] Advantageously, protecting the hair against damage induced by exposure to oxidative stress includes preventing damage to the hair shaft, limiting oxidation or carbonylation of hair shaft proteins, limiting hair porosity and roughness.

[0037] Alterations of the hair shaft, excess porosity and roughness are induced by repeated washing, by chemical treatments, such as coloring, or heat treatments, but also by certain environmental factors, including UV radiation, atmospheric pollutants, salt or even chlorine.

[0038] In the context of this invention, the expression "hair shaft impairment" refers to a condition of the hair linked to oxidative damage that has led to a degradation of the hair keratins. This impairment compromises the structural integrity of the hair, causing a significant increase in its porosity and roughness. This impairment is characterized by a lifting of the cuticles on the surface of the hair, thus affecting its appearance and texture. This definition encompasses the visible manifestations of hair deterioration, highlighting the impact of oxidative damage on the health and aesthetics of the hair.

[0039] The term "protected hair shaft" refers to a condition of the hair in which the structure and function of the hair fiber are maintained in optimal conditions. In this state, the hair is preserved from the harmful effects of oxidative damage that can compromise the structure and cohesion of hair keratins and the overall integrity of the hair. Protection of the hair shaft thus ensures a significant reduction in excessive porosity and roughness, preventing the disorderly detachment of the cuticles on the surface of the hair. The result is hair whose integrity is preserved, resulting in a soft texture, increased shine and better overall manageability, reflecting a visual and tactile appearance of health and vitality.

[0040] By “liposoluble extract” according to the invention, it is understood that the apolar (lipophilic) compounds have been solubilized and / or have been extracted in an apolar solvent.

[0041] Thus, according to the invention, the extract comes from an algae of the genus Laminaria of the class of Phaeophyceae.

[0042] Phaeophyceae are algae of the Ochrophyta phylum. They are also referred to as "brown algae".

[0043] The inventors of the present invention have thus demonstrated, using tests carried out directly on hair, that an oily extract of an algae of the genus Laminaria is capable of preventing oxidative damage, including excess porosity and roughness at the level of the hair shaft caused by oxidative stress, in particular by oxidation coloration.

[0044] In particular, according to the invention, the protection of the hair shaft against multiple stresses for a protected hair includes the prevention of alteration of the structure of the keratins which make up 85 to 95% of the hair shaft.

[0045] The application of the extract according to the invention in fact makes it possible to prevent the oxidation or carbonylation of the proteins which constitute the hair shaft, induced in particular by oxidation coloration.

[0046] Maintaining the structure of keratins thus ensures tight cuticles on the surface of the hair shaft for optimal integrity and aesthetics of the hair.

[0047] Advantageously, the extract is derived from Laminaria ochroleuca, Laminaria digitata, Laminaria hyperborea, Laminaria saccharina, or Undaria pinnatifida, preferably from Laminaria ochroleuca.

[0048] Advantageously, the Laminaria extract is characterized by:

[0049] - An unsaponifiable content of between 0.6 and 15 g / kg of extract, preferably between 5 and 10 g / kg.

[0050] - A sterol content (cholesterol and [3-sitosterol] between 6 and 12 mg / kg of extract, preferably between 5 and 10 mg / kg.

[0051] According to one embodiment of the invention, the extract is integrated into a composition intended for hair application, in which the quantity of extract is greater than or equal to 0.01% and less than or equal to 5% by weight, preferably between 0.1 and 3%, relative to the total weight of the composition.

[0052] Advantageously, the cosmetic composition for hair application may be presented in various forms suitable for use, including, but not limited to, shampoos, conditioners, hair masks, hair oils, serums, lotions, detangling sprays, coloring products, smoothing products, anti-hair loss treatments, styling mousses, gels, styling waxes, balms, heat protection sprays, styling products, hair tonics, anti-dandruff treatments, and sprays volumizing. These shapes are designed to meet the specific needs of hair and scalp, offering a variety of options for care and styling.

[0053] Such a hair composition may of course include one or more other compounds, including, but not limited to, colorants to adjust or enhance the color of the hair, film-forming agents to form a protective film around the hair fiber, surfactants to help cleanse and evenly distribute the product on the hair and scalp, fragrances to improve the odor of the product, preservatives to extend the life of the product, emulsifiers to stabilize emulsion-type formulations, oils to nourish and moisturize the hair, UV filters to protect the hair from sun damage, vitamins such as biotin and panthenol to strengthen and revitalize the hair, proteins to rebuild and fortify the hair fiber, plant extracts for their various benefits on the health of the scalp and hair, silicones to add shine and softness,anti-frizz agents to combat frizz, and any other compound suitable for cosmetic application of the composition, aimed at improving the health, appearance, or manageability of the hair.

[0054] The invention also relates to a cosmetic treatment process for the hair, characterized in that it consists of applying a liposoluble extract from an algae of the genus Laminaria, as defined above, or a composition containing it, to the hair and / or the scalp.

[0055] This treatment aims to nourish, protect and repair the hair fiber, specifically targeting damage caused by environmental, chemical, or thermal factors, while preserving or restoring the health and aesthetics of the hair.

[0056] The preparation of the extract used in the context of the invention can be carried out as indicated below.

[0057] Algae can be harvested at an early stage as well as at a mature stage. These can be subjected to a partial or even total drying stage.

[0058] Preferably, the algae is harvested fresh and then partially dried to ensure better reproducibility of the composition of the extract.

[0059] Any extraction method known to those skilled in the art and making it possible to extract unsaponifiable compounds, including, but not limited to, sterols, fatty alcohols, triterpenes, carotenoids or vitamins, may be used to prepare the extract contained in the composition according to the invention. This includes in particular maceration, digestion, decoction, infusion, but also the use of techniques such as extraction by ultrasound, by microwaves or even the use of subcritical or supercritical fluids. Suitable solvents include glycerol triheptanoate, vegetable oils, esterified oils, or alkanes such as hexane or heptane.

[0060] The preparation of the extracts suitable for the invention is carried out according to conventional techniques which generally implement a grinding step followed by an extraction step. The extraction methods clearly fall within the skills of those skilled in the art. Generally speaking, they use an extraction solvent which is of course chosen for its ability to extract the unsaponifiable compounds contained in the plants in question.

[0061] This extraction solvent may be an apolar solvent, in particular an oily solvent such as triglycerides, glycerol triheptanoate, a vegetable oil such as sunflower oil, or an alkane. Preferably, the extract is a triglyceric extract.

[0062] The extraction may optionally be preceded by enzymatic hydrolysis (proteases, glucanases, etc.) in order to improve the extraction yield. The extraction may optionally be carried out under microwave conditions.

[0063] For example, the extract according to the invention can be obtained by immersing the plant raw material in a hot solvent with a raw material / solvent mass ratio of between 1 / 2 and 1 / 100, for a period of a few hours, for example five hours. The temperature of the solvent used can be in particular between approximately 20 and 80°C. Preferably and advantageously, the extract can be obtained by extracting the raw material using an extraction vehicle containing triglycerides. The temperature of this solvent can be in particular between approximately 20 and 80°C, preferably between 20 and 60°C, more preferably between 40 and 60°C. The extraction time can be several hours, for example between 1 and 48 hours, preferably between 2 and 12 hours. The mixture can be mechanically stirred in situ at a speed of between 10 and 1000 rpm.Once extracted, the solid residue of the algae is separated from the extractive solution by decantation or centrifugation. The extract is then filtered through one or more membranes of different thresholds.

[0064] The method for measuring the unsaponifiable fraction is that of the ISO 18609 standard. The sterol composition was determined by gas chromatography coupled with a mass spectrometer (GC-MS). The extracts according to the present invention are characterized by their unsaponifiable and sterol contents.

[0065] The above-mentioned features of the invention, as well as others, will appear more clearly on reading the examples which follow. EXAMPLES

[0066] Example 1: Methods for obtaining extracts according to the invention

[0067] Extraction example A: Extraction using a vegetable oil.

[0068] - Incorporation of 100 kg of Laminaria into 400 kg of sunflower oil.

[0069] - Grinding using an Ultra-turrax type grinder for 6 hours at room temperature ambient.

[0070] - Extraction with stirring for 12 hours at room temperature.

[0071] - Separation of soluble and insoluble phases by decantation and / or centrifugation and / or filtration.

[0072] - The extract is then filtered through bags and then filtered through membranes up to 2 pm.

[0073] Extraction example B: Extraction using triglycerides.

[0074] - Incorporation of 100 kg of Laminaria in 400 kg of triglycerides.

[0075] - Grinding using an Ultra-turrax type grinder for 6 hours at room temperature ambient.

[0076] - Extraction with stirring for 12 hours at room temperature.

[0077] - Separation of soluble and insoluble phases by decantation and / or centrifugation and / or filtration.

[0078] - The extract is then filtered through bags and then filtered through membranes up to 2 pm.

[0079] Extraction Example C: Extraction using glycerol triheptanoate

[0080] - Incorporation of 100 kg of Laminaria in 400 kg of glycerol triheptanoate.

[0081] - Ultrasonic micro-grinding.

[0082] - Extraction with stirring for 4 hours at 50°C.

[0083] - Separation of soluble and insoluble phases by decantation and / or centrifugation and / or filtration.

[0084] - The extract is then filtered through bags and then filtered through membranes up to 2pm.

[0085] Extraction Example D: Extraction using triglycerides with enzymatic pretreatment

[0086] - Incorporation of 100 kg of Laminaria in 500 kg of osmosis water.

[0087] - Addition of an enzymatic preparation containing a mix of proteases and glucanases.

[0088] - Hydrolysis at a temperature of 50°C for 3 hours.

[0089] - Denaturation of enzymes at 90°C for 15 minutes.

[0090] - Separation of soluble and insoluble phases by decantation and / or centrifugation and / or filtration.

[0091] - Re-extraction of the algae substrate by triglycerides, at a rate of 100 kg of algae for 400 kg of solvent, for 12 hours at room temperature.

[0092] - Separation of soluble and insoluble phases by decantation and / or centrifugation and / or filtration.

[0093] - The extract is then filtered through bags and then filtered through membranes down to 2 pm. solvents are evaporated under vacuum.

[0094] Example 2: Determination of the unsaponifiable and sterol contents of extracts of algae of the genus laminaria

[0095] The method for measuring the unsaponifiable fraction is that of the ISO 18609 standard. The analysis of the content of unsaponifiables and free and esterified sterols is carried out on 7 species.

[0096] The results obtained are presented in Table 1 below:

[0097] [Tables 1] Species Extraction solvent Unsaponifiables (g / kg) Sterols (pg / g) Cholesterol + [3-sitosterol] Laminaria ochr oleuca Glycerol triheptanoate 8.2 10 Laminaria digit ata Glycerol triheptanoate 7.5 8.8 Laminaria hype rborea Glycerol triheptanoate 5.1 10 Laminaria sacc harina Glycerol triheptanoate 5.3 9.3 Undaria pinnat ifida Glycerol triheptanoate 8.8 11

[0098] Advantageously, the Laminaria extract is characterized by:

[0099] The unsaponifiable contents per kilogram of extract are between 0.6 and 15 g / kg of extract, preferably between 5 and 10 g / kg.

[0100] The sterol contents (cholesterol and [3-sitosterol] per gram of extract are between 6 and 12 mg / kg of extract, preferably between 5 and 10 mg / kg.

[0101] Studies on extracts from different species of algae of the genus Laminaria show that the concentrations of unsaponifiables and sterols are quite similar to each other. This similarity indicates a consistency in the composition of unsaponifiable compounds and sterols within the genus, suggesting a constant quality and composition, independent of the specific species.

[0102] Example 3: prevention of oxidative damage to the hair shaft

[0103] The objective of this study is to evaluate the efficacy of liposoluble extracts from Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida in the protection of hair proteins against oxidative damage induced by oxidation dyes, which are among the most harmful aggressions for hair.

[0104] Operating mode:

[0105] The extracts used are liposoluble extracts of Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida obtained according to the extraction method presented in Example 1 (method C).

[0106] The extracts were directly diluted to 3% in the oxidation coloring product and applied to virgin hair for 30 min as recommended by the coloring protocol.

[0107] The hair is then rinsed thoroughly with clean water and then dried naturally before proceeding with the marking of the oxidized proteins.

[0108] The control strands were not colored while the stressed strands were colored by the oxidation coloring not containing the liposoluble extracts.

[0109] After treatments and sampling, carbonylated proteins corresponding to oxidative damage on hair shafts were labeled and detected using a fluorescent probe specific to carbonyl groups.

[0110] Fluorescent images were taken with an epi-fluorescent microscope and analyzed with hnageL software

[0111] Acquisition conditions were identical for all samples. Carbonylation intensity was measured by integration of the specific fluorescence signal, normalized by the evaluated data.

[0112] TABLE 2 below summarizes the significant protective effects of the fat-soluble extracts of Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida against oxidative damage to hair shaft proteins induced by oxidation staining.

[0113] For statistics, values ​​of p<0.001 are considered highly significant (***), (Student's t-test compared to control hair colored without extract).

[0114] [T ables 2] Fluorescence intensity corresponding to the carbonylation intensity Undyed, untreated virgin control hair Colored control hair without extract Colored hair + liposoluble extract of Lamin aria ochro leuca 3% Colored hair + liposoluble extract of Lamin aria digitata 3% Colored hair + liposoluble extract of Lamin aria sacch arina 3% Colored hair + liposoluble extract of Laminaria hyperborea 3% Colored hair + liposoluble extract of Undar ia pinnatif ida 3% Mean 100 377 199*** 223*** 222*** 235*** 215*** Standard deviation 2 8 6 10 7 8 6 Variation rate +277% -47% -41% -41% -38% -43% ation pros vs Hair vs Hair vs Hair vs Hair vs Hair ux controls ux controls ux controls teines carbo vs chev les colorful les colorful les colorful colored without the colored nylées eux vier s without ext s without ext s without ext s extracted without ext ges rait rait rait rait

[0115] Oxidation staining strongly induced the appearance of carbonylated proteins by +277%, confirming the severe oxidative damage caused by this type of chemical treatment.

[0116] The various liposoluble extracts of the genus Laminaria applied to the hair at 3% during oxidation coloring significantly prevented the formation of carbonylated proteins.

[0117] Example 3: Maintaining the integrity of the hair shaft

[0118] This study aims to examine whether fat-soluble extracts from Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida can preserve the integrity of the hair shaft despite exposure to oxidation coloring, which is known to increase hair porosity.

[0119] Operating mode:

[0120] The extracts used are liposoluble extracts of Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida obtained according to the extraction method presented in Example 1 (method C).

[0121] The extracts were directly diluted to 3% in the oxidation coloring product and applied to virgin hair for 30 min as recommended by the coloring protocol.

[0122] The hair is then rinsed thoroughly with clean water and then dried naturally before proceeding with the porosity analysis which reflects the integrity of the hair shaft.

[0123] The control strands were not colored while the stressed strands were colored by the oxidation coloring not containing the liposoluble extracts.

[0124] To evaluate the protective effect of the extracts on the integrity of the hair, the strands are immersed in a fluorescent fluorescein solution and then rinsed.

[0125] After cryopreservation and rapid freezing, cross-sections of hair are analyzed under a microscope to measure the intensity of penetration and diffusion of the marker.

[0126] The images obtained make it possible to quantify the penetration of the fluorophore from the cuticle to the cortex, thus comparing the treatments to virgin hair or to hair colored without the extracts.

[0127] Significant diffusion of fluorescein deep in the hair shaft indicates greater hair porosity. Conversely, blocking this diffusion illustrates the protective efficacy of the extracts, thus preserving the integrity and structure of the hair.

[0128] TABLE 3 below summarizes the significant protective effects of the liposoluble extracts of Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida against the penetration of fluorescein into the hair shaft induced by oxidation staining.

[0129] For statistics, values ​​of p<0.001 are considered highly significant (***), (Student's t-test compared to control hair colored without extract).

[0130] [Tables3] Fluorescein penetration intensity in the hair shaft (%) Undyed, untreated virgin control hair Colored control hair without extract Colored hair + 3% Laminaria ochroleuca liposoluble extract Colored hair + 3% Laminaria digitata liposoluble extract Colored hair + 3% Laminaria saccharin liposoluble extract Colored hair + 3% Laminaria hyper borea liposoluble extract Colored hair + 3% Und aria pinnati fida liposoluble extract Mean 7 18 10*** 12*** 12*** 11*** 13*** Standard deviation 0 1 1 1 1 1 1 Rate of v +168% -41% -33% -33% -39% -28% variation of vs hair vs Hair vs Hair vs Hair vs Hair vs Hair the penetrat ux virgin x control x control x control controls c controls c ion of the fl es s colored ss colored ss colored s olored without olored without uorescein years extract years extract years extract extract extract

[0131] Oxidation staining strongly induced fluorescein penetration by +168%, confirming the increase in porosity and decrease in hair shaft integrity.

[0132] The various liposoluble extracts of the genus Laminaria applied to the hair at 3% during oxidation coloring, significantly prevented the penetration of fluorescein, showing a maintenance of the integrity of the hair fiber by preserving it from an increase in porosity.

[0133] Example 4: prevention of detachment of the cuticles on the surface of the hair shaft causing roughness of the hair

[0134] This study aims to examine whether liposoluble extracts from Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida can preserve the quality of the hair shaft surface despite exposure to oxidation coloring, which is known to increase cuticle detachment responsible for hair roughness.

[0135] Operating mode:

[0136] The extracts used are liposoluble extracts of Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida obtained according to the extraction method presented in Example 1 (method C).

[0137] The extracts were directly diluted to 3% in the oxidation coloring product and applied to virgin hair for 30 min as recommended by the coloring protocol.

[0138] The hair is then rinsed thoroughly with clean water and dried naturally before proceeding with the roughness analysis which reflects the quality of the cuticles and the surface of the hair shaft.

[0139] The control strands were not colored while the stressed strands were colored by the oxidation coloring not containing the liposoluble extracts.

[0140] The hair shafts are marked and analyzed by confocal fluorescence microscopy, XFluo® technology (Kamax Innovative System). Two hundred optical sections are made and used to reconstruct in 3D the surface of the analyzed hair shaft.

[0141] The average roughness is evaluated in pm using 18 measurements for each of the conditions.

[0142] TABLE 4 below summarizes the significant protective effects of the fat-soluble extracts of Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida against roughness induced by oxidation staining.

[0143] For statistics, values ​​of p<0.001 are considered highly significant (***), (Student's t-test compared to control hair colored without extract).

[0144] [Tables4] Roughness at the surface of the hair shafts (pm) Virgin, undyed, untreated control hair Colored control hair without extract Colored hair + liposoluble extract of Laminaria ochroleuca 3% Colored hair + liposoluble extract of Laminaria digitata 3% Colored hair + liposoluble extract of Laminaria saccharin a 3% Colored hair + liposoluble extract of Laminaria hyperbore a 3% Colored hair + liposoluble extract of Undar ia pinnatif ida 3% Mean 0.197 0.233 0.153*** 0.175*** 0.167*** 0.187*** 0.177*** Standard deviation 0.06 0.053 0.027 0.047 0.05 0.031 0.05 Rate of v +19% -34% -25% -28% -20% -24% ariation d vs chev vs Cheveu vs Cheveu vs Cheveu vs Cheveu vs Cheve ela rugos eux vier x controls x control x control x control ux control of surf ges colored without s colored ss colored ss colored s the colored ace of the ts extract years extract years extract years extract years extract s without hair ext ige rait

[0145] Oxidation staining increased the surface roughness of hair shafts by +19%.

[0146] The various liposoluble extracts of the genus Laminaria applied to the hair at 3%, during oxidation coloring, significantly prevented or even reversed this increase in roughness, preserving the quality and integrity of the hair shaft, for more resistant, shiny and soft hair.

[0147] Example 5: maintaining the setting of the oxidation coloration

[0148] In view of the observed effects of the extracts on porosity and roughness, this study aims to examine whether the liposoluble extracts from Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida do not block the rise of color during oxidation coloring.

[0149] Operating mode:

[0150] The extracts used are liposoluble extracts of Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida obtained according to the extraction method presented in Example 1 (method C).

[0151] The extracts were directly diluted to 3% in the oxidation coloring product and applied to bleached white hair for 30 min as recommended by the coloring protocol.

[0152] The measurement of the color rise is carried out with a Konica-Minolta CM2600D spectrocolorimeter, which allows the color to be characterized according to three dimensions (Hue, Value, Saturation, L*a*b*).

[0153] DeltaE*76 (AE*) measures the color difference defined in the L*a*b* color space. It is calculated according to the formula below to evaluate the difference between the hair color before coloring and after coloring, where Ll*, al*, bl* correspond to the L*a*b* values ​​before coloring and L2*, a2*, b2*, to the L*a*b* values ​​after coloring.

[0154] A difference in DeltaE*76 of less than three units is considered undetectable by the human eye and therefore seen as the same color.

[0155] TABLE 5 below summarizes the effects of the fat-soluble extracts of Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida with respect to the rise of color induced by oxidation coloration.

[0156] [Tables5] DeltaE76 * Colored hair without extract Colored hair + liposoluble extract of Laminaria ochroleuca 3% Colored hair + liposoluble extract of Laminaria digitata 3% Colored hair + liposoluble extract of Laminaria sacch arina 3% Colored hair + liposoluble extract of Laminaria hyper borea 3% Colored hair + liposoluble extract of Und aria pinnati fida 3% Mean 47.97 47.92 47.88 47.48 47.87 47.67 Standard deviation 1.14 0.65 0.67 0.65 0.71 0.99

[0157] The different liposoluble extracts of the genus Laminaria applied to the hair at 3% during oxidation coloring did not affect the uptake of the oxidation color, reflected by similar DeltaE76*, regardless of the condition to which the hair was subjected.

[0158] CONCLUSION

[0159] The invention illustrates the remarkable effectiveness of liposoluble extracts of Laminaria including Laminaria ochroleuca, Laminaria digitata, Laminaria saccharina, Laminaria hyperborea and Undaria pinnatifida in protecting the hair shaft against the deleterious effects of oxidative coloring, one of the most deleterious stresses for hair.

[0160] By targeting the mechanisms underlying hair problems, mainly the alteration of keratins by their oxidation or carbonylation, these natural extracts offer an innovative solution to preserve the health of hair by preventing the loss of its integrity and excessive porosity.

[0161] Their application results in strengthened, soft, shiny, and easy-to-style hair, demonstrating the ability of these active ingredients to protect them against a multitude of chemical, thermal, or environmental stresses.

[0162] Thus, the invention highlights a significant advance in hair care, highlighting the importance of natural solutions to combat oxidative damage in order to maintain the integrity of the hair fiber for preserved and aesthetic hair.

Claims

Claims

1. Cosmetic use of a liposoluble extract from a laminaria algae for the protection of hair against damage induced by exposure to oxidative stress, or its repair after such exposure.

2. Use according to claim 1, for the protection of hair during heat treatment, chemical coloring, perming, exposure to UV, atmospheric pollutants, salt or chlorine.

3. Use according to one of the preceding claims, characterized in that the protection includes the prevention of alteration of the hair shaft, the limitation of oxidation or carbonylation of the proteins of the hair shaft, the limitation of the porosity of the hair and its roughness.

4. Use according to one of the preceding claims, characterized in that the extract is derived from Laminaria ochroleuca, Laminaria digitata, Laminaria hyperborea, Laminaria saccharina or Undaria pinnatifida, preferably from Laminaria ochroleuca.

5. Use according to one of the preceding claims, characterized in that the extract is characterized by: - ​​an unsaponifiable content of between 0.6 and 15 g / kg of extract, preferably between 5 and 10 g / kg. - a sterol content of between 6 and 12 mg / kg of extract, preferably between 5 and 10 mg / kg.

6. Use according to one of the preceding claims, characterized in that the extract is integrated into a composition, in which the quantity of extract is greater than or equal to 0.01% and less than or equal to 5% by weight, preferably between 0.1 and 3%, relative to the total weight of the composition.

7. Use according to claim 6, characterized in that the composition is in the form of a shampoo, a conditioner, a hair mask, an oil, a serum, a lotion, a detangling spray, a coloring product, a smoothing product, an anti-hair loss product, a styling mousse, a gel, a styling wax, a balm, a heat protection spray, a styling product, a hair tonic, a dandruff treatment product, or a volumizing spray.

8. Use according to one of claims 6 or 7, characterized in that it includes one or more other compounds such as colorants, film-forming agents, surfactants, perfumes, preservatives, emulsifiers, oils, UV filters, vitamins, proteins, plant extracts, silicones, or anti-frizz agents.

9. Cosmetic treatment process for the hair, characterized in that it consists of applying a liposoluble extract from an algae of the genus Laminaria, or a composition containing it, as defined in one of the preceding claims, to the hair and / or the scalp.

10. A method according to claim 9, characterized in that the application takes place before, during or after coloring, perming, exposure to heat, exposure to UV, exposure to atmospheric pollutants, exposure to salt or exposure to chlorine.