Process for obtaining a composition of algae metabolites for cosmetic use, extracts and compositions obtained from such a process, and cosmetic use of these extracts and compositions

Abstract

The invention relates to a process for obtaining a composition of algae metabolites for cosmetic use, comprising contacting a preparation of at least one wild or cultivated algae with a DES-type solvent, said DES-type solvent being chosen to consist of a mixture comprising at least one compound selected from amino acids, organic acids, alcohols, and sugars. The invention also relates to the extract and the cosmetic composition obtained from the process, as well as the corresponding cosmetic use.

Description

Title of the invention: Process for obtaining a composition of algae metabolites for cosmetic use, extracts and compositions obtained from such a process, and cosmetic use of these extracts and compositions 1. Technical field

[0001] The present invention belongs to the technical field of the extraction of plant material for cosmetic purposes, using in particular natural solvents.

[0002] More particularly, the invention aims to use algae, typically macroalgae, as a biological source material, and to extract targeted active products, usable in the cosmetic industry, from extraction solvents themselves belonging to green chemistry. 2. Prior art

[0003] In recent years, there has been a growing interest in natural skincare and cosmetics, increasing the search for active compounds in natural products. Algae, due to their biological richness, have already been used as a source of plant material to extract active ingredients for cosmetic use.

[0004] Indeed, although they are primarily composed of water, algae contain interesting metabolites and constituents, such as phlorotannins, mannitol, polysaccharides including sugars like glucose or fucose, and hydrophobic compounds such as carotenoids and chlorophylls, as well as other active compounds. Thus, it is known that pure algal molecules or algal extracts can be added to cosmetic formulations for their various properties, such as their moisturizing, firming, or slimming effects.

[0005] Among the known processes for extracting metabolites of algal origin, and more generally of plant origin, are solvent extraction processes.

[0006] A solvent is a substance, generally liquid, that has the capacity to solubilize and dissolve molecules without causing chemical changes to these substances, and without changing itself. More than one hundred tons of organic solvents are produced annually worldwide for industry, but most of them do not comply with the principles of green chemistry, the aim of which is to achieve safe, clean, and energy-efficient chemical processes. Among these principles of green chemistry are the use of less toxic solvents and processing aids, and the use of renewable raw materials.

[0007] The most frequently used solvents are organic solvents such as Hexane, benzene, or acetone. These solvents, among others, largely disregard the principles of green chemistry. Due to their petrochemical origins, these synthetic solvents are the subject of controversy among scientists and the general public. They also have the disadvantage of being volatile, exhibiting low selectivity, and having a limited polarity range.

[0008] Although some solvents are considered non-toxic, such as water, ethanol, or more broadly, alcohols like glycerol, propylene glycol, or butylene glycol, which are widely used in cosmetics, they are not always effective at optimally extracting less polar molecules. Similarly, hydrophobic solvents, such as caprylic / capric triglyceride or sunflower oil, which are widely used in cosmetics, do not offer optimal extraction efficiency for plant metabolites. Their use, particularly for extracting active ingredients to be incorporated into compositions, such as cosmetic formulations, generally does not allow for optimal extraction and / or eliminates the need for preservatives in these compositions.

[0009] This is why neoteric solvents are widely developed to replace traditional solvents. These alternative solvents, in addition to improving selectivity and broadening the polarity range, are used to reduce the toxicity, volatility, and hazard of solvents, and thus better comply with the principles of green chemistry.

[0010] Deep eutectic solvents (DES) belong to this category of new solvents. They are sustainable solvents derived from renewable resources, which are easy to prepare without a purification step. They are generally composed of two or three constituents capable of associating together via hydrogen bonds. They are generally described as a mixture of at least one hydrogen bond acceptor and one hydrogen bond donor with a certain stoichiometry that will form a eutectic, thus giving the mixture a lower melting point than either of the constituents alone. When the constituents of these solvents are compounds found naturally, such as primary plant metabolites, they are called NaDES (Natural Deep eutectic solvent).

[0011] The invention aims precisely to use these DES solvents to extract algae metabolites for cosmetic use.

[0012] NaDES are indeed natural solvents with a strong extraction power: they are also found in nature for the survival of species in extreme conditions, and allow the storage and transport of molecules that are insoluble in water, or where water is scarce. These innovative and effective solvents, which generally eliminate the need for preservatives, are still underutilized in cosmetics. The inventors discovered that their use as Solvent for extracting algae allows the production of active cosmetic extracts, which can be incorporated into various cosmetic compositions.

[0013] It is already known to use NaDES as extraction solvents to produce various extracts from biological material, typically plant or animal.

[0014] Thus, patent application FR3036618A1 published by Gattefossé in December 2016 deals with extraction processes carried out using plant material and the use of so-called "green" solvents prepared from bio-based, biodegradable, and non-toxic molecules. In particular, the aim is to improve existing plant extract preparation processes to meet cosmetic requirements while ensuring adequate quality of the extracts produced. This application proposes producing plant extracts by extraction with NaDES. The NaDES mentioned in this prior document are suitable for extracting plant metabolites from their seeds, leaves, fruits, flowers, and / or bulbs. The only plant cited and tested in this prior patent document is the Calendula officinalis flower. This prior patent document also proposes using the plant extracts produced in the production of, for example, cosmetic compositions.However, these NaDES are not disclosed as being suitable for extracting metabolites from algae.

[0015] Also, patent application FR3034626A1 published by Naturex in October 2016 deals with NaDES for extracting biological material from plants, animals, or prokaryotes. This document mentions that the plant extracts produced can be incorporated into all kinds of compositions, such as cosmetic compositions, but also many other compositions of a food, trace element, pharmaceutical, oenological, or perfume type. With the aim of improving existing extraction processes using NaDES, this document proposes extracting natural biological compounds with specific NaDES, which include betaine. These NaDES have been tested to extract biological metabolites from plants such as cherry blossoms, saffron, rock samphire, rose of Jericho, rosemary, and olive leaves.These betaine-based NaDES, however, are neither discussed nor even disclosed as being suitable for extracting metabolites from algae.

[0016] Furthermore, patent application WO2011 / 155829A1 published by Leiden University in December 2011 deals with a process for extracting biological material for use in the cosmetics industry, but also in many other industries, such as food, pharmaceuticals, and agrochemicals. In particular, with the aim of improving existing extraction processes from natural sources without using synthetic compounds, this application proposes extracting biological material with either NaDES or liquids Ionic. These NaDES and ionic liquids are disclosed as being suitable for extracting metabolites from many types of material, such as plants (vanilla, yew, artemisia, poppy, etc.), insects, animals, and microorganisms. Extraction from red rose flowers has notably been tested. However, the NaDES presented in this document are neither discussed nor disclosed as being suitable for extracting metabolites from algae. 3. Objectives of the invention

[0017] A first object of the present invention consists of implementing in a new way extraction processes applicable to algal resources, and adapted to obtaining extracts for cosmetic use, using NaDES type solvents.

[0018] Another objective of the invention is to select from among DES type solvents formulas of extraction solvents which comply with the principles of cosmetics and cosmetic regulations and which are more effective, in particular in terms of extraction yield of active ingredients, selectivity of these active ingredients, stability of the extracted molecules, and / or which make it possible to do without preservatives.

[0019] No noteworthy publications have been identified concerning the use of natural solvents, particularly NaDES, for the extraction of marine plants, such as algae. It appears that the existing work on this subject is incomplete, and that the tests carried out use, for example, choline chloride in the composition of DES, a compound that is not compatible with cosmetic uses.

[0020] Within the framework of the invention, DES-type solvents have been satisfactorily characterized, according to methods sufficiently reliable to allow for industrialization.

[0021] An objective of the invention is also to propose new algae-based cosmetic compositions including cosmetic active ingredients obtained from extraction processes using these types of solvents.

[0022] These objectives, as well as others which will appear subsequently, are achieved using a method according to the invention. 4. Summary of the invention

[0023] In particular, the invention relates to a method for obtaining a composition of metabolites and / or constituents of algae for cosmetic use, consisting of contacting a preparation of at least one alga (typically, a wild or cultivated macroalga) with a DES-type solvent, said DES-type solvent being chosen to consist of a mixture comprising two or three compounds selected from amino acids, organic acids, alcohols, and sugars, in the presence of water or No.

[0024]

[0025]

[0026]

[0027]

[0028]

[0029] More specifically, the process according to the invention has a first implementation method in the form of a hydrophilic extraction, according to which: - either DES lactic acid / glycerol (1:1) is brought into contact with a preparation of at least one brown macroalga via hydrophilic extraction, to obtain a composition containing in particular phlorotannins and / or small osmolytes such as mannitol; - either DES glycine / arginine / sorbitol (1:1:3) is brought into contact with a preparation of at least one macroalga via hydrophilic extraction, to obtain a composition comprising metabolites and / or constituents of algae containing in particular osmolytes and / or sugars and sugar derivatives including polysaccharides. Advantageously, according to this first hydrophilic extraction method, the process comprises the following steps: - grinding of dried seaweed to obtain flakes of 0.01 to 5 cm wide, preferably 0.05 to 2.5 cm, more preferably 0.1 to 1.5 cm; - contacting said seaweed flakes with said DES, under agitation for a period of between 10 and 60 min, preferably between 20 and 40 min, at a temperature between 30°C and 70°C, preferably between 40°C and 60°C, where the quantity of dried seaweed is between 2 and 6% by weight, preferably between 3 and 5% by weight relative to the total weight of the seaweed / DES mixture; - filtration of the algae residues formed in the previous step on a cloth or sieve with a mesh diameter between 0.1 and 1 mm; - filtration of the final extract obtained on Buchner with filter paper having a filtration capacity of 0.7 and / or 1.2 pm; - recovery of the final extract in liquid form, said extract constituting said composition of algae metabolites for cosmetic use. Advantageously, the said seaweed can be desalinated by soaking in fresh water before drying. Also, advantageously, the said dried seaweed is dried at room temperature in the sun, or in a tobacco dryer, or in a rotary dryer at a temperature between 35°C and 90°C, preferably between 45°C and 80°C, more preferably between 55°C and 70°C. According to another advantageous feature, before the said contacting step, the said DES is adjusted to a water content of between 15% and 60% by weight of water, preferably between 20% and 40% by weight of water. According to another advantageous feature, after the said filtration step of algae residues, the pH of said extract is adjusted between 4 and 7, preferably between 5 and 6, with a 30% sodium hydroxide solution or citric acid.

[0030] It therefore appears that this process according to the invention is simple to implement and control, and has the advantage of not requiring particularly expensive equipment.

[0031] According to the invention, the process has a second embodiment combining hydrophilic extraction and hydrolysis, in particular to allow an additional hydrolysis step, making it possible to degrade in particular the polysaccharides into oligosaccharides and monosaccharides, which are of interest for a wider variety of cosmetic effects.

[0032] In this second embodiment of the process of the invention, DES lactic acid / glycerol (1:1) is contacted with a preparation of at least one macroalga via extraction and hydrolysis, to obtain a composition comprising polysaccharides and / or oligosaccharides and / or monosaccharides, and advantageously comprises the following steps: - grinding of dried seaweed to obtain flakes of 0.01 to 5 cm wide, preferably 0.05 to 2.5 cm, more preferably 0.1 to 1.5 cm; - extraction from said seaweed flakes in the presence of demineralized water, under agitation for a period of between 10 and 60 min, preferably between 20 and 40 min, at a temperature between 10°C and 30°C, preferably between 15°C and 25°C, where the quantity of dried seaweed is between 3 and 5% by weight, relative to the total weight of the seaweed / water mixture; - separation of an insoluble fraction of algae and a first extract formed, by filtration through cloth or sieve with a mesh diameter between 0.1 and 1 mm; - recovery of said insoluble fraction of algae and contacting said DES adjusted to a water content of between 15 and 60% by weight, preferably between 20% and 40% by weight, taking into account the water contained in said insoluble fraction, under agitation for a period of between 1h and 4h, preferably between 1h30 and 3h30, at a temperature of between 50°C and 100°C, preferably between 65°C and 85°C, where the quantity of algae is between 8 and 12% by weight, preferably between 9 and 11% by weight, relative to the total weight of the algae / DES mixture; - adjusting the pH of the mixture between 4 and 7, preferably between 5 and 6, with a 30% sodium hydroxide solution; - cooling of said mixture for a period of between 30 and 90 minutes; - the mixture is adjusted to obtain a total mixture of 50% glycerol, taking into account the glycerol provided by the DES if it contains any; - addition of demineralized water to obtain a final quantity of raw dried seaweed between 3 and 5%, relative to the total weight of the seaweed / DES mixture; - filtration of algae residues formed during the previous steps on canvas or sieve with a mesh diameter between 0.1 and 1 mm; - filtration of the final extract obtained on Buchner with filter paper having a filtration capacity of 0.7 and / or 1.2 pm; - recovery of the final extract in liquid form, said extract constituting said composition of metabolites and / or constituents of algae for cosmetic use.

[0033] Finally, according to a third embodiment of the invention, DES lactic acid / dodecanol is brought into contact with a preparation of at least one macroalga via hydrophobic extraction, to obtain a composition containing in particular carotenoids and / or chlorophylls.

[0034] In this third embodiment, the process advantageously comprises the following steps: - grinding of an alga (dried or not dried / moist) to obtain a paste or pieces of 0.05 to 2.5 cm wide, preferably 0.1 to 2 cm, even more preferably 0.2 to 1.5 cm; - contacting said paste or pieces of seaweed with said DES, under agitation for a period of between 30 and 120 min, preferably between 50 and 70 min, at a temperature below 60°C, preferably between 15°C and 35°C, where the quantity of dried seaweed is between 6 and 10% by weight, preferably between 7 and 9% by weight relative to the total weight of the dry seaweed / DES mixture; - filtration of the algae residues formed in the previous step on a cloth or sieve with a mesh diameter between 0.1 and 1 mm; - separation of an aqueous phase and a phase comprising said DES; - drying of said phase comprising said DES on magnesium sulfate anhydrous; - filtration of the final extract obtained on Buchner with filter paper having a filtration capacity of 0.7 and / or 1.2 pm; - recovery of the final extract in liquid form, said extract constituting said composition of metabolites and / or constituents of algae for cosmetic use.

[0035] Consequently, the invention also covers a whole series of extracts obtained from these processes, namely:

[0036] according to the first method (simple hydrophilic extraction): - extracts from the hydrophilic process, for which the process is applied to extraction from the alga Cystoseira baccata in the presence of DES lactic acid / glycerol (1:1 stoichiometry) in order to include phlorotannins and mannitol after extraction; - extracts obtained using the same process applied to the extraction from the alga Pylaiella littoralis in the presence of DES lactic acid / glycerol (1:1) in order to understand phlorotannins; - extracts obtained according to the same process applied to the extraction from the alga Cystoseira baccata in the presence of DES glycine / arginine / sorbitol (1:1:3) in order to understand sugars and / or sugar derivatives including polysaccharides, such as mannitol or laminaranes; - extracts obtained according to the same process applied to the extraction from the algae Polysiphonia elongata in the presence of DES glycine / arginine / sorbitol (1:1:3) comprising mycosporins, and / or digeneasis, and / or glucose;

[0037] according to the second modality (combination of hydrophilic extraction and hydrolysis): - extracts obtained from this process applied to extraction from the alga Cystoseira baccata, or the alga Codium tomentosum, or the alga Fur-cellaria lumbricalis, or the alga Polysiphonia elongata, or the alga Calli-blepharis jubata, in the presence of DES lactic acid / glycerol (1:1) comprising hydrolyzed polysaccharides, such as laminaranes, and / or fucans, and / or arabinogalactans, and / or mannans, and / or fur-cellaranes, and / or galactans, and / or carrageenans;

[0038] according to the third modality (hydrophobic extraction): - extracts from the hydrophobic extraction process of the invention applied to extraction from the alga Cystoseira baccata, or the alga Codium tomentosum, or the alga Furcellaria lumbricalis, in the presence of DES lactic acid / dodecanol (1:1) comprising hydrophobic compounds, such as carotenoids and / or chlorophylls.

[0039] These various extracts according to the invention can be incorporated as cosmetic ingredients in cosmetic compositions, since they contain interesting natural active principles that are still very uncommon. Indeed, while the extraction of algae metabolites for cosmetic purposes has not yet been fully developed, the use of DES as extraction solvents, combined with the use of algae, also makes it possible to comply with cosmetic regulations by limiting the use of toxic reagents and compounds. Such natural compositions thus present less risk of side effects for their users and correspond to what is re- consumers are looking for.

[0040] The invention also encompasses cosmetic compositions including at least one of the above extracts, as well as the use of each of these extracts as a cosmetic ingredient.

[0041] According to the invention, the cosmetic compositions concerned are in particular intended to be applied to healthy skin, typically to moisturize the skin, and / or to prevent and / or combat skin aging, and / or to improve the skin microbiota and / or improve the skin barrier function and / or to prepare the skin to fight against external oxidative stressors, and / or provide a slimming effect and / or a fat-burning effect and / or a soothing effect.

[0042] Other features and advantages of the invention will appear in the following description in connection with preferred embodiments of the invention. 4. Detailed description

[0043] General introduction on algae and cosmetics

[0044] Marine macroalgae are grouped into three types: brown algae or Phaeophyceae containing brown carotenoid pigments such as fucoxanthin; red algae belonging to the phylum Rhodophyta containing red and blue pigments called phycobilins; and green algae belonging to the phylum Chlorophyta.

[0045] Algae are primarily composed of water and can contain up to 95% of their weight in fresh algae. They also contain numerous other elements, such as mineral salts and trace elements, vitamins, amino acids and proteins, pigments, and phlorotannins. It is the combination of these metabolites that gives them their specific characteristics, providing them with biological properties that can be used in various applications, such as the food industry, the pharmaceutical and medical fields, and cosmetics.

[0046] In particular with regard to the development of the field of natural care and cosmetics, pure algal molecules or in the form of extracts can be added to formulations for their toning, moisturizing, revitalizing, anti-aging, but also anti-cellulite and slimming activities. Algae at the heart of the invention

[0047] Six species of algae were studied in the context of the invention. These are the brown algae Pylaiella littoralis and Cystoseira baccata, the red algae Polysiphonia elongata, Calliblepharis jubata and Furcellaria lumbricalis, as well as the green alga Codium tomentosum.

[0048] These are all eukaryotic macroalgae, selected for their chemical composition, particularly in phenolic compounds, carotenoids, mycosporins or poly saccharides and / or their antioxidant, anti-UV, anti-aging, and moisturizing properties. General introduction to DES

[0049] A DES comprises a hydrogen bond acceptor and a hydrogen bond donor, which, at the correct stoichiometry, combine to create a hydrogen bond network. Non-covalent and non-ionic intermolecular forces are involved. A DES is generally liquid at room temperature (below 100°C).

[0050] Many molecules can be part of the composition of a deep eutectic solvent such as organic acids, amino acids, sugars, alcohols or quaternary ammonium compounds.

[0051] The advantages of using DES as solvents include a reduction in the toxicity of the products used compared to organic solvents, as they are less toxic. They are also non-volatile and non-flammable. They are often biodegradable and biocompatible. They also exhibit strong solvating and extracting power, making them excellent extraction solvents.

[0052] Eutectic solvents, in addition to often being more effective than water, can allow stabilization of extracted algae metabolites and / or constituents and / or limit the use of preservatives.

[0053] The effectiveness of DES for extracting target metabolites is dependent on their polarity; by modifying their composition, the polarity can be modulated, allowing a very wide range of polarities to be obtained thanks to a considerable number of composition possibilities.

[0054] Details of the implementation experiments and testing of the principles of the invention

[0055] As already mentioned, algae produce many active molecules of interest in cosmetics. The objective of this invention was to extract, or even hydrolyze, some of these molecules using innovative solvents: DES.

[0056] Three (3) types of deep eutectic solvents have been prepared in this invention: hydrophilic binary DES, comprising 2 compounds (in the presence of water); hydrophilic ternary DES, comprising 3 compounds (in the presence of water); and hydrophobic DES, comprising 2 or 3 constituents of which at least 1 is hydrophobic, without the addition of water.

[0057] Regarding the nature and quality of the water to be added in the different variants summarized above, the addition of demineralized water is preferred in order to better control purity, reproducibility, and the absence of bacteria. However, those skilled in the art may adapt this according to any secondary objectives.

[0058] It is possible to modulate the DES according to their applications by adjusting their selectivity, polarity or viscosity, in particular by changing one or more constituents of the DES or by changing the amount of water contained in it. ci. For example, adding a 3rd compound (other than water) to a hydrophilic binary DES made it possible to play on the polarity of the solvents.

[0059] Viscosity is one of the limiting factors for the industrial use of eutectic solvents. In particular, increasing the temperature and adding water to hydrophilic DESs influence their viscosity. Consequently, adding water during DES preparation facilitates their production by reducing preparation time and the risk of degradation of the starting components. To maintain the specific extraction properties of the DESs of the invention, a dilution limit of between 30 and 40% water by mass is observed.

[0060] Six (6) specific DES, among others, have been experimentally tested in the context of the invention: - DES lactic acid / glycerol, at stoichiometry 1:1, was tested as an extraction solvent in a hydrophilic extraction process, as well as in a process combining extraction and hydrolysis; - DES lactic acid / dodecanol, at 1:1 stoichiometry, was tested as an extraction solvent in a hydrophobic extraction process; - DES lactic acid / decanol, at 1:1 stoichiometry, was tested as an extraction solvent in a hydrophobic extraction process; - DES glycine / arginine / sorbitol, at stoichiometry 1:1:3, was tested as an extraction solvent in a hydrophilic extraction process; - DES proline / glucose / glycerol at 1:1:1 stoichiometry tested as an extraction solvent in a hydrophilic extraction process; - DES proline / fructose / glycerol at 1:1:1 stoichiometry tested as an extraction solvent in a hydrophilic extraction process.

[0061] The implemented DESs were essentially characterized by cold-source spectrometry, according to the technique described in particular in the publication "Cold-Spray lo-nization Mass Spectrometry of the Choline Chloride-Urea Deep", Percevault et al, 2021 and / or by study of their rheology and / or by dielectric spectroscopy.

[0062] These DESs were used to extract various metabolites and / or constituents, possibly hydrolyzed, from different algae. These DES / process / algae / metabolites and / or constituent combinations are summarized in the table below: # DES Protocol Algae Metabolites and / or constituents 1 Lactic acid / glycerol (1:1) Hydrophilic extraction Brown algae (Cystoseira baccata) Phlorotannins Mannitol 2 Lactic acid / Extraction Brown algae (Phlorotannins Glycerol (1:1) hydrophilic Pylaiella littoralis ) 3 Glycine / arginine / sorbitol (1:1:3) Hydrophilic extraction Cystoseira baccata Sugars and sugar derivatives including polysaccharides (Mannitol) 4 Glycine / arginine / sorbitol (1:1:3) Hydrophilic extraction Polysiphonia elongata Mycosporins Digeneasides Glucose 5 Lactic acid / dodecanol (1:1) Hydrophobic extraction Cystoseira baccata Hydrophobic compounds (Carotenoids, Chlorophylls) 6 Lactic acid / dodecanol (1:1) Hydrophobic extraction Codium tomentosum Hydrophobic compounds (Carotenoids, Chlorophylls) 7 Lactic acid / dodecanol (1:1) Hydrophobic extraction Furcellaria lumbricalis Hydrophobic compounds (Carotenoids, Chlorophylls) 8 Lactic acid / glycerol (1:1) Extraction and hydrolysis Cystoseira baccata Hydrolyzed polysaccharides (laminaranes, sulfated or unsulfated fucans...) 9 Lactic acid / glycerol (1:1) Extraction and hydrolysis Codium to-mentosum Hydrolyzed polysaccharides (sulfated or unsulfated arabinogalactans, sulfated or unsulfated mannans...) 10 Lactic acid / glycerol (1:1) Extraction and hydrolysis Furcellaria lum-bricalis Hydrolyzed polysaccharides (furcellaranes...) 11 Lactic acid / glycerol (1:1) Extraction and hydrolysis Polysiphonia elongata Hydrolyzed polysaccharides (sulfated or unsulfated galactans...) 12 Lactic acid / glycerol Extraction and hydrolysis Calliblepharis jubata Hydrolyzed polysaccharides. (1:1) (carrageenans... )

[0063] It is thus observed that these different combinations according to the invention allow the obtaining of various varied compositions of metabolites and / or constituents of algae for cosmetic use, by means of bringing into contact a preparation of at least one algae (typically a macro-alga) with a DES type solvent, said DES type solvent being chosen so as to be made up of a mixture comprising two or three compounds chosen from amino acids, organic acids, alcohols and sugars, in the presence of water or not.

[0064] Incidentally, the efficiency of this process for obtaining varied compositions of algal metabolites could, in any case, be correlated with the fact that these compounds, which are present in nature, could very well form DES within plants. Their formation would allow for the solubilization, storage, and transport of metabolites that are insoluble or poorly soluble in water. This would explain the survival of organisms during germination, cryoprotection, or drought.

[0065] Details of the three embodiments of the process according to the invention

[0066] The very wide pH range possible for DES has made it possible to consider both the extraction of different algal metabolites and the hydrolysis of algal polysaccharides.

[0067] Extraction method with a hydrophilic DES - The seaweed may have been desalinated by soaking in fresh water before drying; - The seaweed was dried at room temperature in the sun or in a tobacco dryer, or in a rotary dryer at a temperature between 35°C and 90°C, preferably between 45°C and 80°C, more preferably between 55°C and 70°C; - It was then ground in a blender to obtain flakes of 0.01 to 5cm wide, preferably 0.05 to 2.5cm, more preferably 0.1 to 1.5cm; - The DES, previously prepared, which can be adjusted to a water content between 15% and 60% water, preferably between 20% and 40%, was brought into contact with the seaweed flakes under agitation for a period of between 10 and 60 min, preferably between 20 and 40 min, at a temperature between 30°C and 70°C, preferably between 40°C and 60°C, where the quantity of dried seaweed is between 2% and 6% by weight, preferably between 3% and 5% by weight relative to the total weight of the seaweed / DES mixture; - The algae residues were then filtered through cloth or sieves with a mesh diameter between 0.1 and 1 mm; - The pH of the extract can optionally be adjusted between 4 and 7, preferably

[0068]

[0069]

[0070]

[0071]

[0072] tiellement between 5 and 6, with a 30% sodium hydroxide solution or citric acid; - The final extract was filtered on a Buchner with filter paper having a filtration capacity of 0.7 and / or 1.2 pm; - The final extract in liquid form was recovered. The DES used to implement this hydrophilic extraction process are lactic acid / glycerol (stoichiometry 1:1), proline / glucose / sorbitol (stoichiometry 1:1:1), proline / glucose / glycerol (stoichiometry 1:1:1), proline / fructose / glycerol (stoichiometry 1:1:1) and glycine / arginine / sorbitol (stoichiometry 1:1:3). The preferred DES are lactic acid / glycerol and glycine / arginine / sorbitol. Extraction process with a hydrophobic DES - The seaweed may have been desalinated by soaking in fresh water; - The wet / undried or dried seaweed, at room temperature in the sun or in a tobacco dryer, or in a rotary dryer at a temperature between 35°C and 90°C, preferably between 45°C and 80°C, more preferably between 55°C and 70°C, has been ground in a blender to obtain a paste or pieces of 0.05 to 2.5 cm wide, preferably 0.1 to 2 cm, even more preferably 0.2 to 1.5 cm; - The DES, previously prepared, is brought into contact with the paste or pieces of seaweed under agitation for a period of between 30 and 120 min, preferably between 50 and 70 min, at a temperature below 60°C, preferably between 15°C and 35°C, where the quantity of dried seaweed is between 6% and 10% by weight, preferably between 7% and 9% by weight relative to the total weight of the seaweed / DES mixture; - Algae residues were filtered through cloth or sieves with a mesh diameter between 0.1 and 1 mm; - An aqueous phase and a phase including DES were separated; - The phase containing DES was dried on anhydrous magnesium sulfate; - The final extract was filtered on a Buchner with filter paper having a filtration capacity of 0.7 and / or 1.2 pm; - The final extract in liquid form was recovered. The DES used to implement this hydrophobic extraction process are lactic acid / dodecanol DES (1:1 stoichiometry) and lactic acid / decanol DES (1:1 stoichiometry). The preferred DES is lactic acid / dodecanol DES.

[0073] Process for extracting and hydrolyzing polysaccharides with a hydrophilic DES - The seaweed may have been desalinated by soaking in fresh water before drying; - The seaweed was dried at room temperature in the sun or in a tobacco dryer, or in a rotary dryer at a temperature between 35°C and 90°C, preferably between 45°C and 80°C, more preferably between 55°C and 70°C; - It was then ground in a blender to obtain flakes of 0.01 to 5cm wide, preferably 0.05 to 2.5cm, more preferably 0.1 to 1.5cm; - An extraction was then carried out from the seaweed flakes in the presence of demineralized water, under agitation for a period of between 10 and 60 min, preferably between 20 and 40 min, at a temperature between 10°C and 30°C, preferably between 15°C and 25°C, where the quantity of dried seaweed is between 3% and 5% by weight, relative to the total weight of the seaweed / water mixture; - An insoluble fraction of algae and a first extract formed were separated by filtration through cloth or sieve with a mesh diameter between 0.1 and 1 mm; - The insoluble fraction of algae was recovered and brought into contact with the previously prepared DES, which was adjusted to a water content of between 15% and 60% by weight, preferably between 20% and 40% by weight, taking into account the water contained in the insoluble fraction, under agitation for a period of between 1h and 4h, preferably between 1h30 and 3h30, at a temperature of between 50°C and 100°C, preferably between 65°C and 85°C, where the quantity of raw dry algae is between 8% and 12% by weight, preferably between 9% and 11% by weight, relative to the total weight of the dry algae / DES mixture; - The pH of the mixture was adjusted between 4 and 7, preferably between 5 and 6, with a 30% sodium hydroxide solution; - The mixture was left to cool for a period of between 30 and 90 minutes; - the mixture was adjusted to obtain a total mixture of 50% glycerol, taking into account the glycerol provided by the DES if it contains any. - Demineralized water was added to obtain a final quantity of raw dried seaweed between 3% and 5%, relative to the total weight of the seaweed / DES mixture; - Algae residues were filtered through cloth or sieves with a mesh diameter between 0.1 and 1 mm; - The final extract was filtered on a Buchner with filter paper having a filtration capacity of 0.7 and / or 1.2 pm; - The final extract in liquid form was recovered.

[0074] The DES used to implement this polysaccharide extraction and hydrolysis process is DES lactic acid / glycerol (stoichiometry 1:1).

[0075] It is possible for a person skilled in the art to obtain from algae oligosaccharides of different molecular weights and degrees of polymerization, and therefore associated with different biological and chemical properties, by playing on the DES and the temperature used in the hydrolysis, without going out of the scope of the invention.

[0076] To validate the effectiveness of the processes and extracts of the invention, tests were carried out, the results of which are shown in the summary table below.

[0077] Column 2 of this table indicates the relevant DES / process / algae / metabolite combination as referenced in the combination table shown earlier in this description. Test No. # Extraction Protocol Composition of Extraction Solvent Algal Species In vitro Efficacy Test Results A 9 Hydrophilic extraction and hydrolysis Lactic acid / glycerol / water Codium to-mentosum Increase in hyaluronic acid (synthesized mainly by fibroblasts to improve the extracellular matrix (ECM)) - Decrease in MMP-1 (responsible for the degradation of dermal collagen) - Decrease in IL-8 (inflammatory cytokine) - Increase in the growth of S. epidermidis (commensal skin bacterium) in a glucose-depleted environment B 10 Furcellaria lumbricas - Increase in hyaluronic acid (synthesized mainly by fibroblasts to improve the extracellular matrix (ECM)) - Increase in the growth of S. epidermidis (commensal skin bacterium) in a glucose-depleted environment - Increase in commensal flora (S. epidermidis) vs pathogenic (S. aureus and C.acne) C 8 Cystoseira baccata - Increase in hyaluronic acid (synthesized mainly by fibroblasts to improve the extracellular matrix (ECM)) - Increase in the growth of S. epidermidis (commensal skin bacterium) in glucose-depleted medium D 1 Hydrophilic extraction Lactic acid / Cystoseira baccata - Increase in hyaluronic acid (synthesized mainly by fibroblasts to improve the extracellular matrix (ECM)) Glycerol / water secretly by fibroblasts to improve the extracellular matrix (ECM)) - Decrease in MMP-1 (responsible for the degradation of dermal collagen) - Decrease in lipid accumulation (caused by a decrease in the differentiation of preadipocytes into adipocytes) - Increase in the expression of the UCP1 protein (induction of the beige (pro-thermogenic) phenotype) E 3 Hydrophilic extraction Arginine / Glycine / Sorbitol / water Cystoseira baccata - Decrease in IL-8 (inflammatory cytokine) - Decrease in lipid accumulation (caused by a decrease in the differentiation of preadipocytes into adipocytes) - Increase in the expression of the UCP1 protein (induction of the beige (pro-thermogenic) phenotype) Description of results

[0078] Test A: Extract of Codium tomentosum (#9 of the previous Table of "combinations" DES / processes / algae / metabolites and / or constituents)

[0079] In vitro tests were performed on human fibroblasts in a cell monolayer. The extract increased hyaluronic acid production compared to control cells irradiated with UVA at 5 J / cm² and unirradiated cells. These results are positive and suggest that the extract improves the extracellular matrix at the dermal level for an anti-aging and moisturizing effect, subject to in vivo testing.

[0080] In vitro tests were performed on human fibroblasts in a cell monolayer. The extract reduced MMP-1 production compared to control cells irradiated with UVA at 5 J / cm². These results suggest that the extract reduces collagen degradation for an anti-aging effect.

[0081] In vitro tests were carried out on human fibroblasts in cell monolayer. The extract reduces IL-8 production compared to control cells irradiated with UVA at 5J / cm2. These results suggest that the extract regulates inflammatory processes for a soothing or anti-redness effect.

[0082] An in vitro bacterial growth test of the S. epidermidis strain in a glucose-depleted medium showed that the extract improves the growth of the commensal (beneficial skin) bacterium S. epidermidis in a glucose-depleted (glucose-free) medium. These results suggest that it improves the skin microbiota with a prebiotic effect, i.e., an increase in beneficial saprophytic flora for better skin protection and a barrier effect.

[0083] Test B: Extract of Furcellaria lumbricas (#10 of the previous Table of "combinations" DES / processes / algae / metabolites and / or constituents)

[0084] In vitro tests were performed on human fibroblasts in a cell monolayer. The extract increased hyaluronic acid production compared to control cells irradiated with UVA at 5 J / cm² and non-irradiated cells. These results suggest that the extract improves the extracellular matrix at the dermal level for an anti-aging and moisturizing effect, subject to in vivo testing.

[0085] An in vitro bacterial growth test of the S. epidermidis strain in a glucose-depleted medium showed that the extract improves the growth of the commensal (beneficial skin) bacterium S. epidermidis in a glucose-depleted (glucose-free) medium. These results suggest that it improves the skin microbiota with a prebiotic effect, i.e., an increase in beneficial saprophytic flora for better skin protection and a barrier effect.

[0086] An in vitro test was performed on reconstructed human epidermis (RHE) to evaluate the adhesion and proliferation of three bacterial strains: Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), and Cu-tibacterium acnes (C. acnes). The extract increases the commensal flora (beneficial skin bacteria: S. epidermidis) at the expense of the pathogenic flora (C. acnes + S. aureus). An excess of these pathogens can cause imbalances (acne or dryness), but they are nevertheless always present. These results suggest that it regulates the skin microbiota by preventing the proliferation of pathogenic bacteria.

[0087] Test C: Extract from Cystoseira baccata (#8 of the previous table of "combinations" DES / processes / algae / metabolites and / or constituents)

[0088] In vitro tests were performed on human fibroblasts in a cell monolayer. The extract increased hyaluronic acid production compared to control cells irradiated with UVA at 5 J / cm² and non-irradiated cells. These results suggest that the extract improves the extracellular matrix at the dermal level for an anti-aging and moisturizing effect.

[0089] An in vitro bacterial growth test of the S. epidermidis strain in medium A glucose-depleted environment has been shown to improve the growth of the commensal (beneficial) skin bacterium *S. epidermidis* in a glucose-depleted (glucose-free) environment. These results suggest that it improves the skin microbiota with a prebiotic effect, meaning an increase in beneficial saprophytic flora for better skin protection and a barrier effect.

[0090] Test D: Extract from Cystoseira baccata (#1 of the previous Table of "combinations" DES / processes / algae / metabolites and / or constituents)

[0091] In vitro tests were performed on human fibroblasts in a cell monolayer. The extract increased hyaluronic acid production compared to control cells irradiated with UVA at 5 J / cm² and non-irradiated cells. These results suggest that the extract improves the extracellular matrix at the dermal level for an anti-aging and moisturizing effect.

[0092] In vitro tests were performed on human fibroblasts in a cell monolayer. The extract reduced MMP-1 production compared to control cells irradiated with UVA at 5 J / cm². These results suggest that the extract reduces collagen degradation for an anti-aging effect.

[0093] An in vitro test was performed on human preadipocytes to evaluate the effect of extracts on adipogenesis. The extract reduces lipid accumulation and therefore the differentiation of preadipocytes into adipocytes (anti-adipogenic). These results suggest that the extract has anti-lipid storage properties for a slimming effect.

[0094] An in vitro test was performed on human preadipocytes to evaluate the effect of the extract on the induction of the beige phenotype. The extract increases the expression of the UCP1 protein, which reflects an increase in the induction of the beige phenotype in preadipocytes (pro-thermogenic effect). These results suggest that the extract has fat-burning properties.

[0095] Test E: Extract of Cystoseira baccata (#3 of the previous Table of "combinations" DES / processes / algae / metabolites and / or constituents)

[0096] In vitro tests were performed on human fibroblasts in a cell monolayer. The extract reduces IL-8 production compared to control cells irradiated with UVA at 5 J / cm². These results suggest that the extract regulates inflammatory processes for a soothing or anti-redness effect.

[0097] An in vitro test was performed on human preadipocytes to evaluate the effect of extracts on adipogenesis. The extract reduces lipid accumulation and therefore the differentiation of preadipocytes into adipocytes (anti-adipogenic). These results suggest that the extract has anti-lipid storage properties for a slimming effect.

[0098] An in vitro test was performed on human preadipocytes to evaluate the effect of the extract on the induction of the beige phenotype. The extract increases the expression of the UCP1 protein, which reflects an increase in the induction of the beige phenotype. preadipocytes (pro-thermogenic effect). These results suggest that the extract has fat-burning properties. Efficacy Testing Protocols

[0099] The efficacy test protocols were as follows:

[0100] Hyaluronic acid

[0101] Test performed on a monolayer culture of human fibroblasts (BJ cells). - Day 0: Implantation of human BJ cell line (fibroblasts) - Day 1: Treatment of cells with extracts + control without extract - Day 2: Irradiation of cells with UVA at 5 J / cm² to simulate stress + control without extract, without irradiation - Day 4: recovery of supernatants for ELIS A assay of hyaluronic acid (ng / mL)

[0102] MMP-letIL-8

[0103] Test performed on a monolayer culture of human fibroblasts (BJ cells). - Day 0: Implantation of human BJ cell line (fibroblasts) - Day 1: Treatment of cells with extracts + control without extract - Day 2: Irradiation of cells with UVA at 5 J / cm² to simulate stress + control without extract, without irradiation - Day 4: recovery of supernatants for multiplex assay of MMP-1 (pg / mL) and IL-8 (CXCL8) (pg / mL) Growth of S. epidermidis

[0104] The bacterial strain S. epidermidis ATCC® 14990™ was cultured in glucose-depleted medium (Tryptone Broth) and the growth of this strain was determined by reading the optical density at 600 nm in continuous kinetics over a period of 24 hours in order to determine the growth curve.

[0105] Test performed on reconstructed human epidermis (RHE) used at J10.

[0106] Preparation of a bacterial mix containing approximately 5 x 10⁶ CFU / RHE for the strains S. aureus (ATCC® 6538™, Gram+) and C. acnes (ATCC® 6919™, Gram+) and 1 x 10⁷ CFU / RHE for the strain S. epidermidis (ATCC® 14990™, Gram+), i.e., 50% S. epidermidis, 25% S. aureus, and 25% C. acnes. A topical application (50 µl / RHE) of the extracts or water (for the controls) was performed on the RHEs before a 24-hour pre-incubation. The medium was then replaced, and the bacterial mix was added to the RHEs (for the infected conditions). After 4 hours of incubation, the RHEs were rinsed, and the treatments were repeated. The RHEs were incubated again for 20 hours before being frozen at -80°C. For analysis, the RHEs were mechanically ground using a tissue grinder, and the γ-DNA from each sample was extracted. Quantification was performed by qPCR. The experimental conditions were carried out n=5 per condition and gene analysis in n=2 per sample.

[0107] The preadipocytes used are human preadipocytes cultured in 2D under proadipogenic conditions. The extracts to be tested are added directly to the culture medium. The preadipocytes are cultured with or without the extracts for 12 days, with the media being changed every 2–3 days during the culture period. All processing conditions were performed in triplicate culture. The media were then collected, and the preadipocytes were fixed with 4% paraformaldehyde before being incubated with an anti-UCP1 primary antibody overnight. After washing, the cells were incubated with the secondary antibody and then with DAPI (4',6-Diamidino-2-Phenylindole Dihydrochloride) and BODIPY at room temperature to visualize the nuclei and intracellular lipid droplets, respectively.The quantifications of nuclei, lipid accumulation and UCPl expression were performed by an automated method for detecting nuclei and lipid droplets as well as an imaging and processing method for quantifying surface area and fluorescence intensity.

Claims

Demands

1. A process for obtaining a composition of algae metabolites for cosmetic use and / or algae constituents for cosmetic use, consisting of contacting a preparation of at least one wild or cultivated algae with a DES-type solvent, said DES-type solvent being among DES lactic acid / glycerol, DES glycine / arginine / sorbitol and DES lactic acid / dodecanol.

2. A method according to claim 1, wherein said preparation of at least one wild or cultivated alga is contacted with said DES-type solvent via a hydrophilic extraction process, and wherein DES lactic acid / glycerol is contacted with said wild or cultivated alga selected from Cystoseira baccata and Pylaiella littoralis; or wherein said DES glycine / arginine / sorbitol is contacted with said wild or cultivated alga selected from Cystoseira baccata and Polysiphonia elongata.

3. A process according to claim 2, comprising the following steps: - grinding said dried algae to obtain flakes 0.01 to 5 cm wide, preferably 0.05 to 2.5 cm, more preferably 0.1 to 1.5 cm; - contacting said algae flakes with said DES, under agitation for a period of between 10 and 60 min, preferably between 20 and 40 min, at a temperature between 30°C and 70°C, preferably between 40°C and 60°C, where the quantity of dried algae is between 2% and 6% by weight, preferably between 3% and 5% by weight relative to the total weight of the algae / DES mixture; - filtering the algae residues formed in the previous step through a cloth or sieve with a mesh diameter of between 0.1 and 1 mm; - optional adjustment of the pH of the extract between 4 and 7, preferably between 5 and 6, with a 30% sodium hydroxide solution or citric acid;- filtration of the final extract obtained using a Buchner funnel with filter paper having a filtration capacity of 0.7 and / or 1.2 µm; - recovery of the final extract in liquid form, said extract constituting said composition of algae metabolites for cosmetic use.

4. A method according to claim 2, wherein said hydrophilic extraction is a hydrolysis, and wherein said DES

5. Lactic acid / glycerol is brought into contact with said wild or cultivated algae selected from Cystoseira baccata, Codium tomentosum, Furcellaria lumbricas, Polysiphonia elongata, and Calliblepharis jubata. The process according to claim 4 is characterized in that it comprises the following steps: - grinding of said dried seaweed to obtain flakes of 0.01 to 5 cm wide, preferably 0.05 to 2.5 cm, more preferably 0.1 to 1.5 cm; - extraction from said seaweed flakes in the presence of demineralized water, under agitation for a period of between 10 and 60 min, preferably between 20 and 40 min, at a temperature between 10°C and 30°C, preferably between 15°C and 25°C, where the quantity of dried seaweed is between 3% and 5% by weight, relative to the total weight of the seaweed / water mixture; - separation of an insoluble fraction of algae and a first extract formed, by filtration through cloth or sieve with a mesh diameter between 0.1 and 1 mm; - recovery of said insoluble fraction of algae and contacting with said DES adjusted to a water content of between 15% and 60% by weight, preferably between 20% and 40% by weight, taking into account the water contained in said insoluble fraction, under agitation for a period of between 1h and 4h, preferably between 1h30 and 3h30, at a temperature of between 50°C and 100°C, preferably between 65°C and 85°C, where the quantity of dry algae is between 8% and 12% by weight, preferably between 9% and 11% by weight, relative to the total weight of the algae / DES mixture; - adjusting the pH of the mixture between 4 and 7, preferably between 5 and 6, with a 30% sodium hydroxide solution; - cooling of said mixture for a period of between 30 and 90 minutes; - adjusting the mixture to obtain a total mixture of 50% glycerol, taking into account the glycerol provided by the DES if it contains any; - addition of demineralized water to obtain a final quantity of raw dried seaweed between 3% and 5%, relative to the total weight of the seaweed / DES mixture; - filtration of the algae residues formed in the previous step on a cloth or sieve with a mesh diameter between 0.1 and 1 mm; - filtration of the final extract obtained on Buchner with filter paper having a filtration capacity of 0.7 and / or 1.2 pm; - recovery of the final extract in liquid form, said extract constituting said composition of metabolites and / or constituents of algae for cosmetic use.

6. A method according to claim 1, wherein said preparation of at least one wild or cultivated alga is contacted with said DES-type solvent via a hydrophobic extraction process, and wherein said DES lactic acid / dodecanol is contacted with said wild or cultivated alga selected from Cystoseira baccata, Codium tomentosum and Furcellaria lumbricas.

7. A preparation method according to claim 6 comprising the following steps: - grinding said seaweed (dried or undried / moist) to obtain a paste or pieces from 0.05 to 2.5 cm wide, preferably from 0.1 to 2 cm, even more preferably from 0.2 to 1.5 cm; - bringing said paste or pieces of seaweed into contact with said DES, under agitation for a period of between 30 and 120 min, preferably between 50 and 70 min, at a temperature below 60°C, preferably between 15°C and 35°C, wherein the quantity of dried seaweed is between 6% and 10% by weight, preferably between 7% and 9% by weight relative to the total weight of the seaweed / DES mixture; - filtration of the algae residues formed in the previous step on a cloth or sieve with a mesh diameter between 0.1 and 1 mm; - separation of an aqueous phase and a phase comprising said DES;- drying of said phase comprising said DES on anhydrous magnesium sulfate; - filtration of the final extract obtained on a Buchner funnel with filter paper having a filtration capacity of 0.7 and / or 1.2 µm; - recovery of the final extract in liquid form, said extract constituting said composition of algae metabolites for cosmetic use.

8. Extract comprising algae metabolites and / or algae constituents obtained by implementing an extraction process according to any one of claims 1 to 7 employing a DES-type solvent, said DES being selected from DES lactic acid / glycerol, DES glycine / arginine / sorbitol and DES lactic acid / dodecanol.

9. Extract according to claim 8, and obtained by carrying out the process according to any one of claims 2 or 3, comprising phlorotannins and / or mannitol in the case of hydrophilic extraction in the presence of DES lactic acid / glycerol (1:1); and comprising sugars and / or sugar derivatives including polysaccharides, such as mannitol or laminaranes, and / or mycosporins, and / or digeneasis, and / or glucose in the case of hydrophilic extraction in the presence of DES glycine / arginine / sorbitol (1:1:3).

10. Extract according to claim 8, and obtained by carrying out the process according to claim 4 or 5, comprising hydrolyzed polysaccharides, such as laminaranes, and / or sulfated or unsulfated fucans, and / or sulfated or unsulfated arabinogalactans, and / or sulfated or unsulfated mannans, and / or furcellaranes, and / or sulfated or unsulfated galactans, and / or carrageenans.

11. Extract according to claim 8, and obtained by implementing the process according to claim 6 or 7, comprising hydrophobic compounds, such as carotenoids and / or chlorophylls.

12. Cosmetic composition comprising an extract according to any one of claims 8 to 11.

13. Use of an extract according to any one of claims 8 to 11 as a cosmetic ingredient.

14. Use of a composition according to claim 12 as a cosmetic composition intended to be applied to healthy skin.

15. Cosmetic use according to any one of claims 13 or 14 to moisturize the skin, and / or to prevent and / or combat skin aging, and / or to improve the skin microbiota, and / or to prepare the skin to fight against external oxidative stressors and / or improve the skin barrier function and / or a slimming effect and / or a fat-burning effect.