WO2024062078A1

WO2024062078A1 - Method for obtaining an algae metabolite composition for cosmetic use, extracts and compositions derived from such a method and cosmetic use of said extracts and compositions

Info

Publication number: WO2024062078A1
Application number: PCT/EP2023/076157
Authority: WO
Inventors: Lucie PERCEVAULT; Ludovic Paquin; Emmanuelle Limanton; Eric Guivarch
Original assignee: Agrimer
Priority date: 2022-09-22
Filing date: 2023-09-21
Publication date: 2024-03-28
Also published as: FR3139992A1

Abstract

The invention relates to a method for obtaining a composition of algae metabolites for cosmetic use, consisting in bringing a preparation of at least one wild or cultivated alga into contact with a DES-type solvent, said DES-type solvent being chosen to consist of a mixture comprising at least one compound chosen from the amino acids, organic acids, alcohols and sugars. The invention also relates to the extract and the cosmetic composition resulting from the method, and to the corresponding cosmetic use.

Description

DESCRIPTION

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

Technical field of the invention

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

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

Technical background

In recent years, an appeal for natural care and cosmetics has been growing, increasing the search for active compounds within natural products. Algae, due to their biological richness, have already been used as a source plant material to extract active products for cosmetic use.

Indeed, although they are mainly composed of water, algae include interesting metabolites and constituents, such as phlorotannins, mannitol, polysaccharides consisting in particular of sugars such as glucose or fucose or even hydrophobic compounds such as for example carotenoids and chlorophylls, as well as other active compounds. Thus, we know that pure algal molecules or in the form of extracts can be added to cosmetic formulations for their varied properties, such as their hydrating, firming or even slimming activity.

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

A solvent is a generally liquid substance which has the capacity to solubilize and dissolve molecules without causing chemical modification of these substances, and without modifying itself. More than a hundred tonnes of organic solvents are produced per year worldwide for industry, but most of them do not correspond to the principles of green chemistry, the aim of which is to obtain safe, clean and energy efficient chemical processes. Among these principles of green chemistry, we can cite the use of less toxic solvents and auxiliaries, or the use of renewable raw materials.

The most frequently used solvents are organic solvents such as hexane, benzene or acetone. All of these solvents hardly respect these principles of green chemistry. These synthetic solvents, due to their petrochemical sourcing, are the subject of controversies among scientists and the general public. They also have the disadvantage of being volatile, having low selectivity and having a restricted polarity range. Although certain solvents are considered non-toxic, such as water, ethanol or more broadly alcohols, such as glycerol, propylene glycol or butylene glycol widely used in the cosmetic field, these are not always effective in optimally extracting less polar molecules. Likewise, hydrophobic solvents, such as caprylic/capric triglyceride or even sunflower oil, widely used in cosmetics, do not have optimal extraction efficiency for plant metabolites. Their use, in particular to extract active ingredients to be integrated into compositions, such as cosmetic compositions, most of the time does not allow optimal extraction and/or to do without preservatives in these compositions.

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 dangerousness of solvents, and thus respect the principles of green chemistry a little more.

Deep Eutectic Solvents (DES) belong to these new solvents. These 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 the mixture of at least one acceptor and one hydrogen bond donor that has a certain stoichiometry will form a eutectic, thus giving a lower melting point to the mixture than to each of the constituents. When the constituents of these solvents are compounds naturally occurring in nature, such as the primary metabolites of plants, they are called NaDES (“Natural Deep Eutectic Solvent”).

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

NaDES are in fact natural solvents advantageously presenting a strong extraditing power: they would also be present in nature for the survival of species in extreme conditions, and would allow the storage and transport of molecules not soluble in water, or when there is little water. These innovative and effective solvents, which generally eliminate the need for preservatives, are still little used in cosmetics. The inventors have discovered that their use as an algae extraction solvent makes it possible to obtain cosmetic active extracts, which can be integrated into various cosmetic compositions.

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

Thus, patent application FR3036618A1 published by Gattefossé in December 2016 deals with extraction processes carried out from plant material, and the use of so-called “green” solvents, prepared from biosourced, biodegradable and non-toxic molecules. In particular, with the aim of improving the processes for preparing existing plant extracts so that they satisfy cosmetic requirements while ensuring adequate quality of the extracts produced. This application proposes to produce plant extracts by extraction with NaDES. The NaDES mentioned in this previous document are capable of 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 flower Calendula officinalis. This prior patent document also proposes to use the plant extracts produced in the production, for example, of cosmetic compositions. But these NaDES are not disclosed as being capable of extracting algal metabolites.

Also, patent application FR3034626A1 published by Naturex in October 2016 deals with NaDES to extract plant, animal, or even prokaryotic biological material. This document mentions that the plant extracts produced can be integrated into all kinds of compositions, such as cosmetic compositions, but also many other compositions of the food, nutraceutical, pharmaceutical, oenological type, or even perfumes. With the aim of improving existing extraction processes using NaDES, this document proposes to extract natural biological compounds with very specific NaDES, which include betaine. These NaDES have been tested to extract biological metabolites from plants, such as cherry blossoms, saffron, samphire, Jericho rose, rosemary, and even olive leaves. However, these betaine-based NaDESs are not discussed, or even disclosed, as being capable of extracting algae metabolites.

Again, patent application WO2011/155829A1 published by the University of Leiden 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 those of food, pharmacy, or even agrochemicals. In particular, with the aim of improving existing extraction processes from natural sources without using synthetic compounds, this application proposes to extract biological material with either NaDES or ionic liquids. These NaDES and ionic liquids are disclosed to be suitable for the extraction of metabolites from many types of materials, such as plants (vanilla, Taxus plant, Artemisia plant, Papaver plant, etc.), insects , animals, or even microorganisms. In particular, extraction from red rose flowers was tested. The NaDES presented in this document, however, are not discussed, or even disclosed, as being capable of extracting algal metabolites.

Objectives of the invention

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.

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

No notable publications have been identified relating to the use of natural solvents, in particular NaDES, for the extraction of marine plants, such as algae. It appears that the known work on this subject is incomplete, and that the tests carried out use, for example, choline chloride in the composition of DES, a compound which is not compatible with cosmetic uses.

In the context of the invention, DES type solvents have been characterized satisfactorily, according to methods sufficiently reliable to be able to envisage industrialization.

An objective of the invention is also to propose new cosmetic compositions based on algae including cosmetic active ingredients resulting from extraction processes using these types of solvents.

These objectives, as well as others which will appear subsequently, are achieved using a method according to the invention.

Summary of the invention

In particular, the invention relates to a process for obtaining a composition of metabolites and/or constituents of algae for cosmetic use, consisting of bringing into contact a preparation of at least one alga (typically, a macro-alga wild or cultivated) with a DES type solvent, said DES type solvent being chosen so as to consist of a mixture comprising two or three compounds chosen from amino acids, organic acids, alcohols and sugars, in the presence water or not.

More precisely, the process according to the invention finds a first method of implementation in the form of a hydrophilic extraction, according to which: either the lactic acid / glycerol DES (1:1) is brought into contact with a preparation of minus a brown macro-algae via a hydrophilic extraction, to obtain a composition containing in particular phlorotannins and/or small osmolytes such as mannitol, i.e. DES glycine / arginine / sorbitol (1:1:3) is brought into contact with a preparation of at least one macro-algae via hydrophilic extraction, to obtain a composition comprising metabolites and/or algal constituents containing in particular osmolytes and/or sugars and sugar derivatives including polysaccharides.

Advantageously, according to this first method of hydrophilic extraction, the process comprises the following steps: grinding a dried algae to obtain flakes of 0.01 to 5 cm wide, preferably of 0.05 to 2.5 cm, plus preferably 0.1 to 1.5 cm; bringing said algae flakes into contact with said DES, with stirring 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 to the total weight of the algae/DES mixture; filtration of algae residues formed in the previous step on canvas or sieve with a mesh diameter of between 0.1 and 1 mm;

-filtration of the final extract obtained on Büchner 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, said algae can be desalinated by soaking in fresh water before drying.

Also, advantageously, said dried algae 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 characteristic, before said contacting step, 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 characteristic, after said step of filtering the 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 acid. citric.

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.

Still according to the invention, the process finds a second method of implementation combining hydrophilic extraction and hydrolysis, in particular so as to allow an additional hydrolysis step, making it possible to degrade in particular the polysaccharides into oligosaccharides and monosaccharides, interesting for a variety wider range of cosmetic effects.

In this second modality of the process of the invention, the lactic acid/glycerol DES (1:1) is brought into contact with a preparation of at least one macro-algae via extraction and hydrolysis, to obtain a composition comprising polysaccharides and/or oligosaccharides and/or monosaccharides, and advantageously comprises the following steps: grinding a 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; extraction from said algal flakes in the presence of demineralized water, with stirring for a period of between 10 and 60 min, preferably between 20 and 40 min, at a temperature of between 10°C and 30°C, preferably between 15°C and 25°C, where the quantity of dried algae is between 3 and 5% by weight, relative to the total weight of the algae/water mixture; separation of an insoluble fraction of algae and a first extract formed, by filtration on a cloth or sieve whose mesh diameter is between 0.1 and 1 mm; recovery of said insoluble fraction of algae and brought into contact 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, with stirring for a period of between 1 hour and 4 hours, preferably between 1 hour 30 minutes and 3 hours 30 minutes, at a temperature 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; adjustment of 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 min; 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 algae between 3 and 5%, relative to the total weight of the algae/DES mixture; filtration of algae residues formed during the previous stages on canvas or sieve with a mesh diameter of between 0.1 and 1 mm; filtration of the final extract obtained on Büchner 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 metabolites and/or algae constituents for cosmetic use.

Finally, according to a third method of implementing the invention, it is the lactic acid/dodecanol DES which is brought into contact with a preparation of at least one macro-algae via a hydrophobic extraction, to obtain a composition containing notably carotenoids and/or chlorophylls.

In this third modality, the process advantageously comprises the following steps: grinding an algae (dried or not dried/wet) to obtain a paste or pieces of 0.05 to 2.5 cm wide, preferably 0.1 at 2 cm, even more preferably 0.2 to 1.5 cm; bringing said paste or said pieces of algae into contact with said DES, with stirring 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 algae is between 6 and 10% by weight, preferably between 7 and 9% by weight relative to the total weight of the dry algae/DES mixture; filtration of algae residues formed in the previous step on canvas or sieve with a mesh diameter of between 0.1 and 1 mm; separation of an aqueous phase and a phase comprising said DES; drying said phase comprising said DES over anhydrous magnesium sulfate; filtration of the final extract obtained on Büchner 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 metabolites and/or algae constituents for cosmetic use.

Consequently, the invention also covers a whole series of extracts resulting from these processes, namely: according to the first modality (extraction

iile sim

extracts from the hydrophilic process, for which the process is applied to extraction from the alga Cystoseira baccata in the presence of lactic acid/glycerol DES (1:1 stoichiometry) in order to include phlorotannins and mannitol after extraction; the extracts obtained according to the same process applied to the extraction from the alga Pylaiella littoralis in the presence of lactic acid/glycerol DES (1:1) in order to include phlorotannins; the 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 include sugars and/or sugar derivatives including polysaccharides , such as mannitol or laminaranes; the 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 digeneaside, and/or glucose. according to the second modality (combination of hydrophilic extraction and hydrolvse): the extracts resulting from this process applied to the extraction from the alga Cystoseira baccata, or the alga Codium tomentosum, or the alga Furcellaria lumbricalis, or the alga Polysiphonia elongata, or the alga Calliblepharis 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 furcellarans, and/or galactans, and/or carrageenans. according to the third modality (hydrophobic extraction): the extracts resulting from the hydrophobic extraction process of the invention applied to extraction from the alga Cystoseira baccata, or from the alga Codium tomentosum, or from the alga Furcellaria lumbricalis, in the presence of lactic acid/dodecanol DES (1:1) comprising hydrophobic compounds, such as carotenoids and/or chlorophylls.

These different extracts according to the invention can be integrated as cosmetic ingredients in cosmetic compositions, due to the fact that they contain interesting natural active ingredients which are still very little widespread. Indeed, while the extraction of algal metabolites for cosmetic purposes has not yet been fully developed, the use of DES as extraction solvents, associated with the use of algae, also makes it possible to comply with cosmetic regulations, 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 consumers are looking for.

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.

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 fight against skin aging, and/or to improve the skin microbiota and/or or improve the barrier function of the skin and/or to prepare the skin to fight against external oxidative stress, and/or provide a slimming effect and/or a fat-burning effect and/or a soothing effect.

Other characteristics and advantages of the invention will appear in the description which follows in connection with preferred embodiments of the invention.

Detailed description of the invention

General introduction to algae and cosmetics

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

Algae is mainly composed of water and can contain up to 95% of the weight of the fresh algae. They also include many other elements, such as mineral salts and trace elements, vitamins, amino acids and proteins, pigments, and even phlorotannins. It is all of these metabolites that will make them specific, notably providing them with biological properties that can be used in different applications, such as the food industry, the pharmaceutical and medical fields, or even cosmetics.

Particularly 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

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, Cal I i bl epharis jubata and Furcellaria lumbricalis, as well as the green alga Codium tomentosum. These are all eukaryotic macroalgae, selected for their chemical composition, particularly in phenolic compounds, carotenoids, mycosporins or polysaccharides and/or their antioxidant, anti-UV, anti-aging and moisturizing properties. General introduction to DES

A DES includes an acceptor and a hydrogen bond donor, which, at the right stoichiometry, combine to create a network of hydrogen bonds. Non-covalent and non-ionic intermolecular forces are at play. A DES is generally liquid at room temperature (below 100°C).

Many molecules can be included in the composition of a deep eutectic solvent such as organic acids, amino acids, sugars, alcohols or even quaternary ammoniums.

The advantages of using DES as solvents are, among other things, linked to a reduction in the toxicity of the products used compared to organic solvents, because they are less toxic. They are also non-volatile and non-flammable. They are often biodegradable and biocompatible. They also have a strong solvating and extradant power, which makes them very good extraction solvents.

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

The effectiveness of DES for extracting target metabolites is dependent on their polarity; by modifying their composition, the polarity can be modulated, making it possible to obtain a very varied range of polarities thanks to a considerable number of composition possibilities.

Details of implementation experiments and testing of the principles of the invention

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

Three (3) types of deep eutectic solvents were 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.

Concerning the nature and quality of the water to be added in the different variants summarized above, it will be preferred to add demineralized water, in order to better control purity, reproducibility and the absence of bacteria. However, those skilled in the art will be able to adapt according to possible secondary objectives.

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

Viscosity is one of the limiting factors for the use of eutectic solvents at the industrial level. Notably, the increase in temperature and the addition of water in hydrophilic DES influence their viscosity. Consequently, adding water when preparing DES makes it easier to obtain these by reducing the preparation time as well as the risk of degradation of the starting constituents. To maintain the specific extraction properties of the DES of the invention, a dilution limit located between 30 and 40% water by weight is observed.

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

The DES implemented were essentially characterized by cold source spectrometry, according to the technique described in particular in the publication “Cold-Spray Ionization Mass Spectrometry of the Choline Chloride-Urea Deep”, Percevault et al, 2021 and/or by study of their rheology and/or by dielectric spectroscopy.

These DESs have been used to extract various metabolites and/or constituents, possibly hydrolyzed, based on different algae.

These DES/processes/algae/metabolites and/or constituents combinations are summarized in the table below:

It can thus be seen that these different combinations according to the invention make it possible to obtain various varied compositions of metabolites and/or constituents of algae for cosmetic use, by means of bringing a preparation of at least one algae into contact ( typically a macro-algae) with a DES type solvent, said DES type solvent being chosen so as to consist of a mixture comprising two or three compounds chosen from amino acids, organic acids, alcohols and sugars, in the presence of water or not.

Incidentally, the effectiveness of this process for obtaining varied compositions of algal metabolites could be correlated, in any hypothesis, with the fact that these compounds which are present in nature could quite form DES inside of plants. Their formation would make it possible to solubilize, store and transport metabolites that are not or poorly soluble in water. This would explain the survival of organisms during germination, cryoprotection or drought phenomena.

Details of the three methods of carrying out the process according to the invention

The very wide pH range possible for DES made it possible to consider both the extraction of different algal metabolites, as well as the hydrolysis of algal polysaccharides.

Extraction process with a hydrophilic DES

The algae was possibly desalinated by soaking in fresh water before drying;

The algae 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. C and 70°C;

It was then ground in a blender to obtain flakes 0.01 to 5 cm wide, preferably 0.05 to 2.5 cm, more preferably 0.1 to 1.5 cm;

The DES, previously prepared, which can be adjusted to a water content between 15% and 60% water, preferably between 20% and 40%, was placed in contact with the algae flakes with stirring for a period of time. 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;

The algae residues were then filtered through a cloth or sieve with a mesh diameter of between 0.1 and 1 mm;

The pH of the extract can optionally be adjusted between 4 and 7, preferably between 5 and 6, with a 30% sodium hydroxide solution or citric acid;

The final extract was filtered through Büchner with filter paper having a filtration capacity of 0.7 and/or 1.2 μm;

The final extract in liquid form was recovered.

The DES used to carry out this hydrophilic extraction process are lactic acid/glycerol DES (1:1 stoichiometry), proline/glucose/sorbitol (1:1:1 stoichiometry), proline/glucose/glycerol (1:1:1 stoichiometry). 1:1), proline / fructose / glycerol (stoichiometry 1:1:1) and glycine / arginine / sorbitol (stoichiometry 1:1:3).

The preferred DESs are lactic acid/glycerol and glycine/arginine/sorbitol DESs.

Extraction process with a hydrophobic DES

The algae was eventually desalinated by soaking in fresh water;

Wet/undried or dried algae, 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 was ground in a blender to obtain a paste or pieces 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 placed in contact with the paste or the pieces of algae while stirring 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 algae is between 6% and 10% by weight, preferably between 7% and 9% by weight relative to the total weight of the algae/DES mixture; The algae residues were filtered through a cloth or sieve with a mesh diameter of between 0.1 and 1 mm;

An aqueous phase and a phase comprising DES were separated;

The phase comprising DES was dried over anhydrous magnesium sulfate; The final extract was filtered through Büchner with filter paper having a filtration capacity of 0.7 and/or 1.2 μm;

The final extract in liquid form was recovered.

The DESs used to carry out this hydrophobic extraction process are lactic acid/dodecanol (1:1 stoichiometry) and lactic acid/decanol (1:1 stoichiometry) DESs.

The preferred DES is lactic acid/dodecanol DES.

Process for the extraction and hydrolysis of polysaccharides with a hydrophilic DES

The algae was possibly desalinated by soaking in fresh water before drying;

An extraction was then carried out from the algal flakes in the presence of demineralized water, with stirring for a period of between 10 and 60 min, preferably between 20 and 40 min, at a temperature of between 10°C and 30 °C, preferably between 15°C and 25°C, where the quantity of dried algae is between 3% and 5% by weight, relative to the total weight of the algae/water mixture;

An insoluble fraction of algae and a first extract formed were separated, by filtration on a cloth or sieve with a mesh diameter of 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, in taking into account the water contained in the insoluble fraction, with stirring for a period of between 1 hour and 4 hours, preferably between 1 hour 30 minutes and 3 hours 30 minutes, at a temperature 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 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 allowed to cool for a period of between 30 and 90 min; 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 algae between 3% and 5%, relative to the total weight of the algae/DES mixture;

The algae residues were filtered through a cloth or sieve with a mesh diameter of between 0.1 and 1 mm;

The final extract in liquid form was recovered.

The DES used to carry out this polysaccharide extraction and hydrolysis process is lactic acid/glycerol DES (1:1 stoichiometry).

It is possible for those 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 varying the DES and the temperature used in hydrolysis, without departing from the scope of the invention.

To validate the effectiveness of the processes and extracts of the invention, tests were carried out, the results of which appear in the summary table below.

Column 2 of this table indicates the DES/processes/algae/metabolite combination concerned as it is referenced in the table of combinations appearing earlier in this description.

Description of results

Test A: Codium tomentosum extract (#9 in the previous table of “combinations” DES/orocedia/algae/metabolites and/or constituents)

In vitro tests were carried out on human fibroblasts in a cell monolayer. The extract increases the production of hyaluronic acid compared to control cells irradiated with UVA at 5J/cm ² and not irradiated. These results are positive and suggest that the extract improves the extra-cellular matrix at the dermal level for an anti-aging and hydrating effect, subject to in vivo tests.

In vitro tests were carried out on human fibroblasts in a cell monolayer. The extract reduces the production of MMP-1 compared to control cells irradiated with UVA at 5J/cm ² . These results suggest that the extract reduces the degradation of collagen for an anti-aging effect.

In vitro tests were carried out on human fibroblasts in a cell monolayer. The extract reduces the production of IL-8 compared to control cells irradiated with UVA at 5J/cm ² . These results suggest that the extract regulates inflammatory phenomena for a soothing or anti-redness effect.

An in vitro test of bacterial growth of the S. epidermidis strain in a glucose-depleted medium was able to show that the extract improves the growth of the commensal bacteria (good bacteria of the skin) S. epidermidis in a depleted medium (without glucose). These results suggest that it improves the skin microbiota with a pre-biotic effect, i.e. an increase in beneficial saprophytic flora for better skin protection and a barrier effect.

Test B: Extract of Furcellaria lumbricalis (#10 of the previous table of “combinations” DES/orocedates/alcs/metabolites and/or constituents)

In vitro tests were carried out on human fibroblasts in a cell monolayer. The extract increases the production of hyaluronic acid compared to control cells irradiated with UVA at 5J/cm ² and not irradiated. These results suggest that the extract improves the extra-cellular matrix at the dermal level for an anti-aging and hydrating effect, subject to in vivo testing.

An in vitro bacterial growth test of the S. epidermidis strain in a glucose-depleted medium was able to show that the extract improves the growth of the commensal bacteria (good bacteria of the skin) S. epidermidis in a depleted medium (without glucose). These results suggest that it improves the skin microbiota with a pre-biotic effect, i.e. an increase in beneficial saprophytic flora for better skin protection and a barrier effect. An in vitro test was carried out on reconstructed human epidermis (RHE) to evaluate the adhesion and proliferation of 3 bacterial strains Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis) and Cutibacterium acnes (C . acnes). The extract increases the commensal flora (good skin bacteria: S. epidermidis) to the detriment of the pathogenic flora (C. acnes + S. aureus). The excess of these pathogens can cause disturbances (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.

Test C: Cvstoseira baccata extract (#8 of the previous table of “combinations” DES/processes/alcs/metabolites and/or constituents)

In vitro tests were carried out on human fibroblasts in a cell monolayer. The extract increases the production of hyaluronic acid compared to control cells irradiated with UVA at 5J/cm ² and not irradiated. These results suggest that the extract improves the extra-cellular matrix at the dermal level for an anti-aging and hydrating effect.

Test D: Cvstoseira baccata extract (#1 in the previous table of “combinations” DES/processes/alcs/metabolites and/or constituents)

An in vitro test was carried out 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.

An in vitro test was carried out on human preadipocytes to evaluate the effect of the extracts 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 of preadipocytes (pro-effect). thermogenic). These results suggest that the extract has fat burning properties.

Test E: Cvstoseira baccata extract (#3 in the previous table of “combinations” DES/orocedia/algae/metabolites and/or constituents)

An in vitro test was carried out on human preadipocytes to evaluate the effect of the extracts 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 of preadipocytes (prothermogenic effect). These results suggest that the extract has fat burning properties.

Efficacy test protocols

The efficacy test protocols were as follows:

Hyaluronic acid

Test carried out on a monolayer culture of human fibroblasts (BJ cells). JO: Implantation of human BJ line cells (fibroblasts)

D1: Treatment of cells with extracts + control without extract

D2: Irradiation of cells with UVA at 5J/cm ² to simulate stress + control without extract without irradiation

D4: recovery of supernatants for ELISA assay of hyaluronic acid (ng/mL)

MMP-1 and IL-8

Test carried out on a monolayer culture of human fibroblasts (BJ cells).

JO: Implantation of human BJ line cells (fibroblasts)

D1: Treatment of cells with extracts + control without extract

D4: recovery of supernatants for multiplex assay of MMP-1 (pg/mL) and IL-8 (CXCL8) (pg/mL) Growth of S. epidermidis

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 to determine the growth curve.

Test carried out on reconstructed human epidermis (RHE) used on day 10.

Preparation of a bacterial mix containing approximately 5x106 CFU/RHE for the strains S. aureus (ATCC® 6538™, Gram+) and C. acnes (ATCC® 6919™, Gram+) and 1x107 CFU/RHE for the strain S. epidermidis ( ATCC® 14990™, Gram+) i.e. 50% S. epidermidis, 25% S. aureus and 25% C. acnes. Topical application (50 μl/RHE) of the extracts or water (for controls) on the RHE was carried out before a 24-hour pre-incubation. The medium was then replaced and the bacterial mix added to the RHE (for infected conditions). After 4 hours of incubation, the RHE were rinsed and the treatments renewed. The RHE were again incubated for 20 hours before being frozen at -80°C. For analysis, RHEs were mechanically ground using the tissue grinder and gDNAs from each sample were extracted. Quantification was carried out by qPCR. The experimental conditions were carried out in n=5 per condition and the analysis of the genes in n=2 per sample.

The preadipocytes used are human preadipocytes cultured in 2D in proadipogenic conditions. The extracts to be tested are added directly to the culture medium. The preadipocytes are cultured in the presence or absence of the extracts for 12 days with a change of media every 2-3 days during the culture period. All treatment conditions were carried out in culture triplicate. Media were then collected and preadipocytes were fixed with 4% paraformaldehyde before being incubated with anti-UCP1 primary antibody overnight. After washes, cells were incubated with the secondary antibody and then with DAPI (4',6-Diamidino-2-Phenylindole, Dihydrochloride) and BODIPY at room temperature to reveal nuclei and intracellular lipid droplets, respectively. Quantifications of nuclei, lipid accumulation and UCPI expression were performed by an automated method for detection of nuclei and lipid droplets as well as an imaging and processing method for quantification of surface area and fluorescence intensity.

Claims

1. Process for obtaining a composition of algae metabolites for cosmetic use and/or algae constituents for cosmetic use, consisting of bringing into contact a preparation of at least one wild or cultivated algae with a solvent of DES type, said DES type solvent being chosen so as to consist of a mixture comprising at least one compound chosen from amino acids, organic acids, alcohols and sugars.

2. Method according to claim 1, in which said preparation of at least one wild or cultivated algae is brought into contact with said DES type solvent via a hydrophilic extraction process.

3. Method according to claim 2, in which said DES type solvent is lactic acid/glycerol DES and said wild or cultivated algae is chosen from Cystoseira baccata and Pylaiella littoralis; or in which said DES type solvent is DES glycine / arginine / sorbitol and said wild or cultivated algae is chosen from Cystoseira baccata and Polysiphonia elongata.

4. Method according to any one of claims 2 and 3, 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; bringing said algae flakes into contact with said DES, with stirring for a period of between 10 and 60 min, preferably between 20 and 40 min, at a temperature of between 30°C and 70°C, preferably between 40°C 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; filtration of algae residues formed in the previous step on canvas 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 on Büchner 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.

5. Method according to claim 2, in which said hydrophilic extraction carried out is a hydrolysis, and in which said DES type solvent is lactic acid/glycerol DES and said wild or cultivated algae is chosen from Cystoseira baccata, Codium tomentosum, Furcellaria lumbricalis, Polysiphonia elongata and Calliblepharis jubata. Method according to claim 5 characterized in that it comprises 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; extraction from said algal flakes in the presence of demineralized water, with stirring for a period of between 10 and 60 min, preferably between 20 and 40 min, at a temperature of between 10°C and 30°C, preferably between 15°C and 25°C, where the quantity of dried algae is between 3% and 5% by weight, relative to the total weight of the algae/water mixture; separation of an insoluble fraction of algae and a first extract formed, by filtration on a cloth or sieve whose mesh diameter is between 0.1 and 1 mm; recovery of said insoluble fraction of algae and brought into contact 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, with stirring for a period of between 1 hour and 4 hours, preferably between 1 hour 30 minutes and 3 hours 30 minutes, at a temperature 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; adjustment of the pH of the mixture between 4 and 7, preferably between 5 and 6, with a 30% sodium hydroxide solution; cooling said mixture for a period of between 30 and 90 min; adjustment of 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 algae between 3% and 5%, relative to the total weight of the algae/DES mixture; filtration of algae residues formed in the previous step on canvas or sieve with a mesh diameter of between 0.1 and 1 mm; filtration of the final extract obtained on Büchner 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 metabolites and/or algae constituents for cosmetic use. Method according to claim 1, in which said preparation of at least one wild or cultivated algae is brought into contact with said DES type solvent via a hydrophobic extraction process, and in which said DES type solvent is acidic DES. lactic acid / dodecanol and said wild or cultivated algae is chosen from Cystoseira baccata, Codium tomentosum and Furcellaria lumbricalis. Preparation process according to claim 7 comprising the following steps: grinding said algae (dried or not dried/wet) 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; bringing said paste or said pieces of algae into contact with said DES, with stirring 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 algae is between 6% and 10% by weight, preferably between 7% and 9% by weight relative to the total weight of the algae/DES mixture; filtration of algae residues formed in the previous step on canvas or sieve with a mesh diameter of 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 Büchner 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. Extract obtained by implementing the process according to any one of claims 2 to 8. Extract according to claim 9, and obtained by implementing the process according to any one of claims 2 to 4, comprising phlorotannins and /or mannitol in the case of hydrophilic extraction in the presence of lactic acid/glycerol DES (1:1); and comprising sugars and/or sugar derivatives including polysaccharides, such as mannitol or laminaranes, and/or mycosporins, and/or digeneases, and/or glucose in the case of hydrophilic extraction in the presence of DES glycine / arginine / sorbitol (1:1:3). Extract according to claim 9, and obtained by carrying out the process according to claim 5 or 6, comprising hydrolyzed polysaccharides, such as laminaranes, and/or fucans, sulfated or not, and/or arabinogalactans, sulfated or not, and/or mannans, sulfated or not, and/or furcellarans, and/or galactans, sulfated or not, and/or carrageenans. Extract according to claim 9, and obtained by carrying out the process according to claim 7 or 8, comprising hydrophobic compounds, such as carotenoids and/or chlorophylls. Cosmetic composition comprising an extract according to any one of claims 9 to 12.

14. Use of an extract according to any one of claims 9 to 12 as a cosmetic ingredient.

15. Use of a composition according to claim 13 as a cosmetic composition intended to be applied to healthy skin. 16. Cosmetic use according to any one of claims 14 and 15 to moisturize the skin, and/or to prevent and/or fight against skin aging, and/or to improve the skin microbiota, and/or to prepare the skin for fight against external oxidative stress and/or improve the barrier function of the skin and/or a slimming effect and/or a fat-burning effect.