Plant extract obtained by a process using a supramolecular solvent, the extract comprising at least one exogenous polysaccharide

Abstract

A plant extract characterized in that it can be obtained by an extraction process from plant material using a supramolecular extraction solvent consisting of a mixture of fructose, glycerin, and water, and in that the extract further contains at least one exogenous polysaccharide. The manufacturing process of the extract and the cosmetic or dermatological composition containing it. Figure for the abstract: Figure 2

Description

Title of the invention: Plant extract obtained by a process using a supramolecular solvent, the extract comprising at least one exogenous polysaccharide. Technical field

[0001] The invention relates to a plant extract obtainable by an extraction process using a supramolecular extraction solvent, the extract comprising at least one exogenous polysaccharide. It also relates to a manufacturing process for the extract and to a cosmetic composition comprising said extract. Previous art

[0002] The use of bio-based green solvents such as Natural Deep Eutectic Solvents (NaDES) or Natural Low Transition Temperature Mixtures (NaLTTM) for the extraction of plant-based raw materials is now well known (see, for example, Dai, Y.; van Spronsen, J.; Witkamp, ​​GJ; Verpoorte, R.; Choi, YH (2013) Natural deep eutectic solvents as new potential media for green technology. In: Analytica Chimica Acta, vol. 766, p. 61-68. DOI: 10.1016 / j.aca.2012.12.019; Choi, Young Hae; Verpoorte, Robert (2019) Green solvents for the extraction of bioactive compounds from natural products using ionic liquids and deep eutectic solvents. In: Current Opinion in Food Science, vol. 26, p. 87-93). DOI: 10.1016 / j.cofs.2019.04.003).These solvents are generally composed of two non-hazardous, plant-based organic constituents and possibly water, which interact through a network of homogeneous hydrogen bonds, resulting in a supramolecular structure. They are excellent candidates for replacing conventional petrochemical-based solvents due to the plant origin of their constituents, their ease of preparation, and their biodegradability.

[0003] In addition, most of these mixtures are low in toxicity, biodegradable, non-flammable, liquid at room temperature and therefore perfectly suited for industrial use.

[0004] On these bases, the Applicant has developed a number of solvents of the NaDES and NaLTTM type.

[0005] Documents FR3053890A1, FR3067939A1 and FR3066118A1 describe, for example, extracts of Aesculus Hippocastanum, Withania somnifera and Sechium edule respectively, obtained using an extraction solvent consisting of a mixture of fructose, glycerin and water. These supramolecular extracts are clear liquids, often colored once filtered at 0.2pm.

[0006] From an eco-design perspective, due to their plant origin and their harmlessness, these solvents have the advantage of being able to be used as an ingredient solvent by the formulator, and therefore do not require an energy-intensive purification and / or concentration step to remove the solvent from the plant extract.

[0007] Despite the many advantages described of these supramolecular plant extracts, their liquid form presents several disadvantages which may limit their exploitation in the cosmetic field due to the rise of the principles of sustainable development, naturalness and regulatory aspects.

[0008] For example, the risk of spillage inherent in liquid products leads to greater difficulties in terms of packaging, secure storage, and transport. Liquid extracts must be packaged in suitable containers (metal or plastic bottles or cans) that are closed and leak-proof to prevent any risk of spillage during transport or storage, which is not the case for solid forms.

[0009] Among other disadvantages, in most plant extracts in liquid form, instabilities, particularly microbiological ones, known to those skilled in the art, can be observed, which are the consequence of phenomena linked to an external factor (oxidation, microbial development).

[0010] These instabilities often necessitate the addition of microbiological preservatives and / or antioxidants. These additives are not always sufficiently effective when they are of plant origin. The addition of microbiological preservatives is thus often accompanied by additional energy-intensive and costly unit operations (bacterial disinfection, sterilizing filtration, sterile packaging) at the industrial level.

[0011] Furthermore, and most importantly, the regulatory framework and naturalness standards governing the marketing of cosmetic products limit the use of preservatives to only a few, most of which are bio-based. The list of microbiological preservatives that can be used in cosmetic extracts or formulas certified organic according to the European Cosmos standard is even more limited.

[0012] The Applicant has found that, quite surprisingly, the addition of at least one polysaccharide to a liquid supramolecular plant extract not only gives it a gelled form preventing any risk of spillage outside the container, but also improves the microbial stability of the extract obtained, in the absence of preservatives, compared to the same extract but in liquid form with or without preservatives.

[0013] Document WO2019219774A2 describes a process for the in-situ formation of a eutectic mixture known as a "gel-like" mixture by mixing a plant-based raw material in gel or gel-like form with at least one exogenous molecule that has a function quaternary, ternary or secondary ammonium. This designation "gel-like eutectic extract" is based on the fact that the extracts obtained are not very fluid or not fluid at all and have viscosities between 10,000 and 250,000 cP, in other words between 10 and 250 Pa.s.

[0014] The viscosities mentioned remain low and do not resolve the aforementioned spillage problem. Furthermore, no information is provided regarding the microbiological stability of the extract obtained.

[0015] A number of documents also describe the possibility of gelling supramolecular solvents with a polysaccharide.

[0016] This is the case of Depoorter J. et al (Depoorter, Jérémy; Mourlevat, Adeline; Sudre, Guillaume; Morfin, Isabelle; Prasad, Kamalesh; Serghei, Anatoli et al. (2019) Fully Biosourced Materials from Combination of Choline Chloride-Based Deep Eutectic Solvents and Guar Gum. In: ACS Sustainable Chemistry & Engineering, vol. 7, n° 19,p. 16747-16756. DOI: 10.1021 / acssuschemeng.9b04228) who describe, for example, the incorporation of guar gum into bio-based DESs based on choline chloride and various hydrogen bond donors: urea, acids, alcohols and sugars. The viscoelastic moduli (G' and G”) increase with the concentration of guar gum and concentrations greater than 10% (w / w) are required to obtain a “solid-like” behavior (G' > G' ' regardless of the frequency of stress).The use of choline chloride is, however, prohibited in cosmetics (Regulation (EC) No 1223 / 2009) and the concentration required to confer the gelling effect remains significant.

[0017] The incorporation of xanthan gum into NaDES composed of choline chloride and various hydrogen bond donors (polyols, citric acid) was studied by Zeng, C. et al. (Zeng, Chaoxi; Zhao, Haiyang; Wan, Zheng; Xiao, Qian; Xia, Huiping; Guo, Shiyin (2020) Highly biodegradable, thermostable eutectogels prepared by gelation of natural deep eutectic solvents using xanthan gum. Preparation and characterization. In: RSC Advances, vol. 10, no. 47, pp. 28376–28382. DOI: 10.1039 / D0RA03390A). The authors demonstrate that the addition of water is necessary to obtain gels after the addition of a significant amount of xanthan gum (>5%) and that water appears to play a role in the structuring of the mixture. The soft materials obtained have a better water retention capacity compared to their purely aqueous analogues.

[0018] With a view to developing more efficient electronic materials, Hong et al. (Hong, Shu; Yuan, Yang; Liu, Chaozheng; Chen, Weimin; Chen, Ling; Lian, Hailan; Liimatainen, Henrikki) (2020) A stretchable and compressible ion gel based on a deep eutectic solvent applied as a strain sensor and electrolyte for supercapacitors. In: Journal of Materials Chemistry C, vol. 8, no. 2, pp. 550–560. DOI: 10.1039 / C9TC05913J They studied the formation of an ionic gel by radical polymerization of an acrylamide monomer in solution in a choline chloride / urea / glycerol DES containing cellulose. These DES / polyacrylamide / cellulose mixtures exhibit interesting mechanical properties, but the preparation process is complex.

[0019] It therefore follows from the above that the gelled supramolecular solvents obtained by adding polysaccharides are all composed of amino substances, and more particularly of choline chloride or its derivatives, the latter being prohibited in cosmetics. Document WO2019 / 219774A2 describes the production of so-called "gelled" plant extracts using a non-gelled supramolecular solvent, the final extract being obtained from a raw material that has been previously gelled before extraction. Description of the invention

[0020] As mentioned previously, the present invention proposes the use of exogenous polysaccharides, in particular of plant, marine or microbial origin not chemically modified to modify the rheological properties of liquid plant extracts obtained after extraction with a supramolecular solvent (NaDES or NaLTTM).

[0021] More specifically, the invention relates to a plant extract which is characterized in that it can be obtained by a process of extracting plant material using an extraction solvent consisting of a mixture of fructose, glycerin and water and in that the extract also contains at least one exogenous polysaccharide.

[0022] In the rest of the description and in the claims, "exogenous polysaccharides" means any polysaccharide not contained in the liquid plant extract, in other words, added after manufacture of the liquid plant extract.

[0023] As will be described later, the Applicant has demonstrated that such an extract also exhibited microbiological stability at least as good, or even better, than the same extract obtained in liquid form.

[0024] The Applicant has also demonstrated that the chemical and biological stability of the gelled plant extract according to the invention, compared to the same plant extract in liquid form, is not modified, which does not appear obvious given the internal chemical rearrangements that may occur at the time of the addition of the polysaccharide.

[0025] The manufacturing process of gelled supramolecular plant extracts of the invention also has the advantage of being simple to implement and industrializable.

[0026] Finally, the extracts obtained have the advantage of being able to be incorporated fa- cilement in cosmetic and / or dermatological compositions.

[0027] The invention can be implemented with any type of plant material, that is to say, any known plant or plant family. The extracts can also be obtained from all or part of one or more plants, that is to say, for example, the seeds, leaves, fruits, flowers and / or bulbs of one or more plants. Furthermore, the plant material can be fresh, dried, whole or ground.

[0028] Preferably, the exogenous polysaccharide is of plant, marine or microbial origin, and is chemically unmodified, that is to say, it has not undergone any chemical modification after its obtaining; in other words, it is in its native state.

[0029] Advantageously, the polysaccharide is chosen from the group of homopolysaccharides and heteropolysaccharides such as, for example, natural gums, carrageenans, advantageously k-carrageenan, alginates, xylans, pectins, hyaluronic acid or agarose derivatives used alone or in mixture.

[0030] Preferably, natural gums are chosen from the group including guar, carob, xanthan gum, acacia.

[0031] Similarly, agarose derivatives are advantageously chosen from the group comprising agaropectins and agar-agar.

[0032] Surprisingly, the Applicant has highlighted the possibility of obtaining viscoelastic supramolecular plant extracts, or even physical gels, in the presence of only a small amount of polysaccharide, compared to the gelled supramolecular solvents of the prior art.

[0033] In practice, the viscosity of the extract of the invention measured using a DHR2 rheometer (cone / plane geometry (diameter 40 mm, angle 2°, gap 52 pm) at a temperature of 20°C, for shear rates between 0.01 and 100 s 1 is greater than 250 Pa.s, preferably greater than 260 Pa.s, preferably between 275 and 10000 Pa.s.

[0034] According to another feature, the extract according to the invention has an elastic modulus G' greater than the viscous modulus G” at least at high frequency, preferably at any frequency.

[0035] Furthermore, and according to another characteristic, the polysaccharide represents less than 5%, advantageously between 0.5 and 2% by weight of the extract.

[0036] According to an advantageous embodiment, the solvent consists of a mixture of fructose, glycerin and water.

[0037] Preferably, the solvent consists of a mixture of fructose, glycerin and water in molar proportions between 1:1:3 and 1:1:7, advantageously in molar proportions of about 1:1:5.

[0038] In a particular embodiment, the solvent consists of a mixture of fructose, glycerin and water in molar proportions of 1:1:5 and the polysaccharide is k-carrageenan.

[0039] As will be seen later, the manufacturing process of the extract of the invention is energy-efficient in that the incorporation of the polysaccharide can be carried out by simple stirring, at moderate temperature and for only a few hours.

[0040] More specifically, the invention also relates to a method for manufacturing a plant extract as described above, comprising the following steps: - solid / liquid extraction by contacting the plant material with the extraction solvent, - solid / liquid separation of the extract obtained, - recovery of the liquid phase of the extract, - Add the polysaccharide to the liquid phase, - Stir until a gelled extract is obtained.

[0041] To guarantee the absence of pathogens and reduce the presence of total aerobic germs below 100 germs per gram, a microfiltration step down to 0.2 µm is interposed between the steps of recovering the liquid phase of the extract and adding the polysaccharide.

[0042] In a particular embodiment, the agitation is carried out at a moderate temperature, generally below 100°C, preferably between 2 and 100°C, preferably between 20 and 80°C, for a period of less than 5 hours, preferably between 0.5 and 3 hours.

[0043] In practice, the polysaccharide / extract mass ratio applied during the polysaccharide addition step is between 0.1 / 99.9 and 5 / 95, preferably between 0.5 / 99.5 and 2 / 98.

[0044] In order to limit the oxidation of the phytochemical compounds in the extract, the addition of polysaccharide can be carried out under an inert atmosphere (nitrogen, argon). This step is preferably carried out in a batch reactor but can also be carried out continuously in an extruder.

[0045] After cooling, a gelled extract is obtained, with a consistency that varies depending on the polysaccharide(s) and concentration(s) used. These products require no further processing.

[0046] The invention also relates to the use, preferably non-therapeutic, of the extracts according to the invention or of compositions comprising them, for the cosmetic treatment of the skin and / or mucous membranes and / or hair.

[0047] In this perspective, the invention also relates to compositions comprising the extract of the invention, preferably cosmetic and / or dermatological compositions, that is to say, compositions suitable for topical application on the skin and / or mucous membranes, and / or the skin appendages.

[0048] In practice, the extract represents between 0.1% and 10%, preferably between 0.5% and 5% by weight of the composition.

[0049] The cosmetic and / or dermatological composition according to the invention can be presented in all the galenic forms normally used for topical application on the skin and / or mucous membranes, and / or hair, for example in anhydrous form, in the form of an oil-in-water emulsion, a water-in-oil emulsion, a multiple emulsion, a silicone emulsion, a microemulsion, a nanoemulsion, a gel, an aqueous solution or a hydro-alcoholic solution.

[0050] This composition may be more or less fluid and may be in the form of a white or colored cream, an ointment, a milk, a lotion, a serum, or a gel.

[0051] The cosmetic and / or dermatological composition may contain excipients commonly used in the cosmetic and dermatological fields, such as fats, detergent and / or conditioning surfactants, emulsifiers and co-emulsifiers, hydrophilic or lipophilic gelling agents, preservatives, antioxidants, solvents, exfoliating agents, perfumes, fillers, hydrophilic and lipophilic filters, colorants, neutralizers, penetrating agents, and polymers. These types of excipients are all well known to those skilled in the art.

[0052] In practice, the quantities of these different excipients are those classically used in the fields considered, and the sum of the excipients preferably represents 0.01% to 30% of the total weight of the composition.

[0053] Suitable fats include mineral oils, animal oils (such as lanolin), vegetable oils, synthetic oils (such as isopropyl myristate, octyldodecyl, isostearyl isostearate, decyl oleate, isopropyl palmitate), and silicone oils (cyclomethicone, dimethicone). Fatty alcohols, fatty acids, waxes, and gums, and in particular silicone elastomers, can also be used as fats.

[0054] Suitable detergent and / or conditioning surfactants may be mentioned as non-ionic, anionic, cationic or amphoteric surfactants, and mixtures thereof, such as, for example, alkyl sulfates, alkyl ether sulfates such as sodium lauryl ether sulfate, alkyl betaines such as cocamidopropyl betaine, or quaternary ammonium salts.

[0055] Suitable emulsifiers and co-emulsifiers include, for example, polyglycerol and fatty acid esters, sucrose and fatty acid esters, sorbitan and fatty acid esters, oxyethylenated fatty acid and sorbitan esters, fatty alcohol and PEG ethers, glycerol and fatty acid esters, alkyl sulfates, alkyl ether sulfates, alkyl phosphates, alkyl polyglucosides, alkyl poly-pentosides, dimethicone copolyols.

[0056] Suitable hydrophilic gelling agents may be cited for example carboxyvinyl polymers, acrylic copolymers (carbomers) such as acrylate / alkylacrylate copolymers, polyacrylamides, polysaccharides such as xanthan gum, guar gum, natural gums such as cellulose gum and derivatives, starches and their derivatives, clays and 2-acrylamido-2-methylpropane copolymers.

[0057] Suitable lipophilic gelling agents include, for example, modified clays such as bentones, metallic salts of fatty acids, hydrophobic silica and ethylcellulose.

[0058] Suitable preservatives may be cited for example benzoic, sorbic, propionic, salicylic, dehydroacetic acids and their salts, benzyl alcohol, ethylhexylglycerin, parabens, their salts and esters, triclosan, imidazolidinyl urea, 5-phenoxyethanol, DMDM ​​hydantoin, diazolidinyl urea, chlorphenesin.

[0059] Suitable antioxidants may be cited for example chelating agents such as EDTA and its salts, sodium metabisulfite, salicylic, ascorbic and citric acids and their salts, sodium tartrate, sodium gluconate, carotenoids and tocopherols.

[0060] As solvents that can be used in the cosmetic composition (distinct from the extraction solvent), we can mention water, ethanol, glycerin, propylene glycol, pro-panediol, butylene glycol, sorbitol.

[0061] Suitable exfoliating agents include, for example, chemical exfoliants such as AHAs, and physical exfoliants such as natural or synthetic powders.

[0062] Suitable fillers may be cited for example talc, kaolin, mica, serecite, magnesium carbonate, aluminium silicate, magnesium silicate, organic powders such as nylon.

[0063] Suitable colorants may be cited for example lipophilic colorants, hydrophilic colorants, pigments and mother-of-pearls commonly used in cosmetic or dermatological compositions, and mixtures thereof.

[0064] Suitable neutralizers may be cited for example sodium hydroxide, triethanolamine, aminomethyl propanol, potassium hydroxide.

[0065] Suitable pro-penetrating agents include, for example, alcohols and glycols (ethanol, propylene glycol), ethoxydiglycol, alcohols and fatty acids (oleic acid), fatty acid esters, dimethyl isosorbide.

[0066] The composition of the invention may also further contain other assets than the extract according to the invention. As suitable active ingredients, examples may be given for example free radical scavengers or more generally antioxidants, whitening agents, pigments, emollients, moisturizers, anti-seborrheic agents, anti-inflammatories, anti-acne agents, keratolytic and / or desquamating agents, anti-wrinkle and firming agents, draining agents, anti-irritant agents, soothing agents, vitamins and their mixtures, mattifying agents, anti-aging actives such as retinol, healing agents, antiseptics and essential oils.

[0067] The invention and the advantages arising therefrom will become clear from the following embodiments supported by the attached figures. Brief description of the drawings

[0068] Fig. 1 is a shaping photograph taken for a gelled extract of Withania somnifera obtained according to the invention.

[0069] Figure [Fig. 2] represents the flow curve of different gelled extracts of Withania somnifera.

[0070] Figure [Fig. 3] represents the dependence of the elastic moduli G' and the viscous moduli G'' on frequency at 20°C for the gelled extracts of Withania somnifera with different polysaccharides.

[0071] Fig. 4 is a representation of the stability monitoring of amino acids contained in gelled extracts of Withania somnifera with different polysaccharides, carried out at 40°C for 5 months.

[0072] Fig. 5 represents 6 graphs illustrating the effectiveness of microbial preservation (challenge test) of gelled and non-gelled extracts of Withania somnifera.

[0073] Fig. 6 is a representation of the anti-radical activity (DPPH) for gelled Polygonum cuspidatum extracts compared to the non-gelled extract after 6 months of storage at 25 and 40°C.

[0074] Fig. 7 corresponds to photographs of microscopic observations of cosmetic formulas prepared with the extract of VF. somnifera gelled with 1% k-carrageenan compared to the control formulas (without extract). Detailed description of the invention

[0075] Example a: Manufacture of a gelled extract of Withania somnifera

[0076] 1 part of dried and crushed root of Withania somnifera is mixed with 19 parts of a fructose / glycerin / water mixture in a 1:1:5 molar ratio (FGE115). The mixture is extracted at 70°C for 3 hours in a stirred reactor. Solid / liquid separation is performed by centrifugation (4600 rpm bucket centrifuge - 20 min). The crude juice is then filtered through a pressure front filter (2 bar) using a cellulose acetate membrane to a final limit of 0.22 µm. The resulting extract is the microbiologically preservative-free equivalent of the extract marketed by the Applicant under the name EnergiNius™.

[0077] One part of polysaccharide (k-carrageenan, or xanthan gum, or sodium alginate, or agar agar) is gradually introduced into 49 to 124 parts of the Withania somnifera root extract thus obtained.

[0078] The mixture (extract + polysaccharide) is then heated to 80°C for 3 hours with mechanical stirring. After this mixing operation, the resulting product is poured hot into a suitable storage container. The container is then sealed, and the gelled extract is cooled either gradually to room temperature or more rapidly by placing it in a positive cold room (4°C).

[0079] After cooling, a gelled extract is obtained. This product does not require any further processing. Depending on the packaging used, the gelled extracts obtained can be shaped as shown in [Fig. 1] for the VF. somnifera extract gelled with 2% k-carrageenan.

[0080] Example 1b: Manufacture of a gelled extract of Polygonum cuspidatum

[0081] The gelled extract is obtained under the same manufacturing conditions described in example 1a, but from ground dried root of Polygonum cuspidatum.

[0082] Example 2: Studies of the rheological properties of gelled extracts of Withania somnifera

[0083] . The viscosity of the different gelled extracts of Withania somnifera is compared prepared according to the conditions of example a as a function of shear rate relative to a liquid extract of Withania somnifera obtained under the same conditions as in example a before addition of the polysaccharide.

[0084] Viscosity measurements are carried out using a DHR2 rheometer (TA instruments). A cone / plane geometry (diameter 40 mm, angle 2°, air gap 52 pm) was used for these measurements carried out at a temperature of 20°C, which is controlled by a Peltier plane.

[0085] The flow curves at 20°C obtained for shear rates between 0.01 and 100 s 1 are shown in [Fig.2].

[0086] First, it is observed that the liquid extract of VF. somnifera exhibits a viscosity independent of the shear rate; it is a Newtonian fluid. This is not the case after the addition of a polysaccharide, since the viscosity of the other systems decreases with increasing shear rate.

[0087] Viscosity values ​​measured at low shear rate for systems containing a polysaccharide are between 275 and 4300 Pa.s.

[0088] Furthermore, the addition of a small amount of polysaccharide makes it possible to significantly increase the viscosity of the liquid extract (0.2 Pa.s).

[0089] Finally, the flow curve obtained on the extract gelled with 1% (w / w) k-carrageenan shows an abrupt break at 10 s⁻¹. This phenomenon is not due to a A sudden decrease in viscosity occurs at the ejection of the product of the geometry. As will be seen below, since this extract exhibits "solid-like" behavior, the viscosity value alone is therefore insufficient to characterize this behavior.

[0090] To do this, viscoelastic modulus measurements should be carried out by frequency scanning using the DHR2 rheometer, as mentioned previously.

[0091] Figure [Fig. 3] represents the dependence of the elastic moduli G' (solid symbols) and the viscous moduli G'' (empty symbols) on the frequency.

[0092] Since the liquid extract is a Newtonian fluid of low viscosity, it has a very low elastic modulus which cannot be precisely determined.

[0093] The result obtained with sodium alginate is characteristic of a viscoelastic fluid. The modulus G' is greater than G” at high frequencies (short times) but G” becomes greater than G' at low frequencies (long times). This explains why the gelled extract obtained after the addition of 1% sodium alginate does not flow spontaneously (G' > G”) but eventually flows after a certain observation period.

[0094] The results obtained with xanthan gum and agar-agar show that the moduli G' are greater than the moduli G'' independently of the frequency and therefore that these products do not flow without constraint.

[0095] Finally, in the case of the addition of 1% (w / w) of k-carrageenan, the moduli are very little dependent on frequency. Moreover, the elastic modulus G' is significantly greater than the viscous modulus G” which, in this specific case, allows us to speak of “solid-like” behavior to describe the rheological properties of this physical gel.

[0096] In conclusion, adding small amounts of polysaccharides to a supramolecular extract significantly increases its viscosity and modifies its rheological properties. In some cases, viscoelastic solutions or physical gels that do not flow spontaneously are obtained. In other cases, true physical gels (from a rheological point of view) are obtained.

[0097] Example 3a: Characterization of the free amino acid composition in the gelled extracts and non-gelled extract of Withania somnifera

[0098] The purpose of this example is to demonstrate that the transformation of the extract obtained in the presence of the solvent FGE from a liquid form to a gelled form does not affect its chemical stability, which is characterized here by the amino acid content.

[0099] To this end, the free amino acid content of the gelled extracts of Withania somnifera obtained in example a is quantified by U-HPLC according to a method developed by Waters with the AccQ-Fluor reagent kit (ref WAT052880). An AccQ-TAG Ultra U-HPLC column (100 mm x 2.1 mm x 0.7 µm) is used. The temperature is set at 55°C and the flow rate at 0.7 mL / min. A UV-DAD detector is used and the Quantification is performed at 260 nm. The gelled extracts are derived at 55°C for 10 minutes after dilution 1 / 5 (w / v) in water. The inserts, in which the amino acid derivatization reaction takes place, are then centrifuged (Eppendorf 3 min. at 13,500 rpm). The supernatant is transferred to a new insert for IpL injection by U-HPLC. Calibration is performed externally using the assay kit. The results obtained, as well as the recovery rates compared to the ungelled liquid extract obtained under the same conditions as in example A before the addition of the polysaccharide, are presented in Table 1.

[0100] Example 3b: Characterization of the stilbenoid composition in the gelled and ungelled extracts of Polygonum cuspidatum

[0101] This example has the same objective as example 3a but for an extract of Polygonum cuspidatum with respect to stilbenoids.

[0102] The stilbenoid (piceide and resveratrol) content in gelled extracts of Polygonum cuspidatum obtained in Example 1b is quantified by HPLC on an Agilent Poroshell 120 EC-C18 column (100 mm x 3 mm x 2.7 pm). The elution solvent is composed of water and acetonitrile. The temperature is set at 50°C and the flow rate at 0.6 mL / min. A UV-DAD detector is used, and quantification is performed at 306 nm. The results obtained, as well as the recovery rates compared to the ungelled liquid extract obtained under the same conditions as in Example 1b, are presented in Table 1. [Table 1] Liquid extract Extract +1.5% agar-agar Extract + 1% kJ-carrageenan Extract: +1% sodium alginate Extract + 0.5% xanthan gum Extracts of Wsomnifera Amino acid content (in ppm / day) 363 347 352 354 366 Recovery rate 100% 95% 97% 98% 101% Extracts of P. cuspidatum Stilbenoid content (in mg / 1000 mL / day) 53 52 53 53 54 Recovery rate 100% 98% 100% 100% 102%

[0103] Tracer recovery rates are greater than 95% regardless of the polysaccharide added to the extracts studied. These results indicate that the process for obtaining gelled extracts described in the invention makes it possible to preserve the phytochemical content initially present in the liquid extract.

[0104] Example 4: Study of the long-term stability (ft0+5 months) of the free amino acid content in gelled and non-gelled extracts of Withania somnifera

[0105] The purpose of this example is to demonstrate that the long-term chemical stability of the gelled extract of the invention is not affected compared to the same extract in its liquid form.

[0106] A phytochemical stability study of gelled extracts was carried out in a glass bottle, protected from light and at 3 temperatures (4, 25 and 40°C) compared to the stability of the ungelled extract. Gelled extracts of IV. somnifera with 4 different polysaccharides and the ungelled extract were prepared as described in example 1a.

[0107] The amino acids contained in the liquid extracts (with and without preservative system) and the 4 gelled extracts exhibit equivalent chemical stability at the 3 temperatures studied.

[0108] Indeed, when the concentrations of free amino acids in the gelled and ungelled extracts of Withania somnifera at time t, denoted Ct, are expressed as a percentage of the composition at t0, denoted C0, amino acid degradation is observed at 40°C ([Fig. 4]). [Fig. 4] shows that all stability profiles are equivalent. Gelling an extract according to the invention under the conditions of the study does not induce amino acid instability.

[0109] Example 5: Study of the effectiveness of microbial preservation

[0110] The measurement of the effectiveness of microbial preservation is carried out according to a challenge test described in the European Pharmacopoeia, 10th edition, 2021 - Chapter 5.1.3: Efficacy of antimicrobial preservation, Preparations for topical applications.

[0111] The test consists of preparing a sample with an inoculum of suitable microorganisms consisting of 3 bacteria and 2 yeasts / molds (respectively Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, and Aspergillus brasiliensis), storing the sample at room temperature, avoiding sunlight, removing samples from the container at specified time intervals, and counting the organisms in the samples thus removed. The microbial preservation efficiency of the product is considered effective if, under the test conditions, there is a significant decrease or no increase, if any, in the number of microorganisms in the inoculated preparation after 2, 7, 14, and 28 days. In the case of bacteria, the count is performed on day 0 and after 2, 7, 14, and 28 days; in the case of yeasts / molds, the count is performed on Day 0 and after 14 and 28 days.Depending on the population decline rate of each inoculated strain, the European Pharmacopoeia assigns different criteria for microbial preservation efficacy, with criterion A being the most demanding. Criterion B, synonymous with very good microbial preservation efficacy, is sufficient for marketing a plant extract. Nevertheless, criterion A is the preferred criterion. manufacturers in the cosmetics sector.

[0112] This study was carried out on gelled and non-gelled extracts (with and without a preservative system) of Withania somnifera according to example 1a. The results of this study are reported in Figures 1 to 6 of [Fig. 5].

[0113] Germ counts at day 0 (D0) were performed on extract samples and polysaccharides alone to determine the initial microbial cleanliness. Then, germ counts in the extracts were performed at days 2, 7, 14, and 28 to determine the microbial preservation efficiency. The microbial cleanliness results obtained are presented in Table 2. [Tables 2] tcSîàte VCsowfc1- W.StW-ifcta + ISC^E W.üwsfea + & 5^:5« VCséwtUta ■ :!• <15 <to < 15 <13 & lec < to te J? ie NC SC SC SC •te <15 <iù te <10 20 Si: SC SC SC <W: < 15 <15 '3 <13 50 50 SC SC NC <33 < 15 <13 SC NC NC NC :ii < 1E <10 < 15 < 30 <33 <E! 15 <3 <10 10 :? <10 <15 < 15 <10 SC SC NC. SC :>< EC < 15 ■■te <10 < ;û SC SC SC SC 114 -te <15 <15 <10 < iC SC ! <c sc <10 <;ô < 15 <13 lu nc :

[0114] The results presented in Table 2 show that even though some polysaccharides contain a detectable microbiological load at 0°C and greater than 100 CFU / g, this load does not develop in the gelled extracts at 0°C, which all comply with the microbiological cleanliness criteria for cosmetic ingredients (<100 CFU / g) after incorporation of polysaccharides. Furthermore, this microbiological cleanliness remains stable and compliant for 28 days at room temperature for all extract samples.

[0115] The results of the challenge tests obtained for all samples demonstrate good microbial preservation efficiency, as they all meet at least criterion B, despite the absence of preservatives. It is noted that the liquid extract with the preservative system exhibits better efficiency than the supramolecular extract alone. However, the addition of preservatives to this extract does not allow it to meet criterion A of the European Pharmacopoeia. Criterion B is also obtained for the gelled extracts with sodium alginate and xanthan gum. This demonstrates the possibility of replacing the use of preservatives with the addition of a polysaccharide. Very interestingly, the polysaccharides agar-agar and k-carrageenan provide an efficiency of Microbial preservation of the gelled extracts complies with criteria A of the European Pharmacopoeia, which is not achieved with the preserved liquid extract. These results show that the gelation of the Withania somnifera extract with polysaccharides allows: - to remain compliant with the microbiological cleanliness criteria for cosmetic ingredients (<100CFU / g) after incorporation of non-sterile polysaccharide, and that this microbiological cleanliness remains stable for 28 days at room temperature. - to obtain, depending on the chemical nature of the polysaccharide, a microbiological preservation efficiency equivalent (compliant with criteria B) or superior (compliant with criteria A) to that of the liquid extract containing a preservative system.

[0116] Example 6: Evaluation of the activity potential of gelled Polygonum cuspidatum extracts according to the invention

[0117] This example aims to demonstrate that the transformation of the extract obtained in the presence of the solvent FGE from a liquid form to a gelled form does not affect the biological stability of the extract, which is characterized here by its antioxidant and anti-radical properties.

[0118] The evaluation of the antioxidant and anti-radical activity potential of 4 gelled extracts of Polygonum cuspidatum obtained in example 1b was carried out in comparison with the non-gelled extract obtained in example 1b.

[0119] The measurements are carried out after 6 months of storage of the samples at 25 and 40°C in an oven protected from light and in closed vials.

[0120] Antioxidant activity is quantified using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. DPPH obtained from Sigma-Aldrich is incubated at room temperature in the absence (untreated) or with increasing concentrations of the product to be evaluated (0.001%; ​​0.005%; 0.01%; 0.05%; 0.1%; 0.5%). After 30 minutes of incubation, the absorbance or optical density (OD) is recorded at 518 nm using a UV spectrophotometer (Tecan, Infinité M1000). A solution without DPPH is also prepared to perform a blank control of the experiment. Two positive controls are used to validate the test: L-cysteine ​​at 5 pg / mL and ascorbic acid (L) at 50 pM. These two witnesses are also supplied via Sigma-Aldrich.

[0121] Antiradical activity (ARS) is calculated according to the following formula: RSA. (%) - 100 - [(DOpmfeû - DOhlanç / DOno» DObianc) X 100]

[0122] The determinations are repeated 6 times (n=6). The results are expressed as % of antiradical activity compared to the untreated and presented in [Fig.6].

[0123] All extracts exhibit similar efficacy profiles. The anti- activity The radical activity illustrated here by a DPPH test proves that the activity potential of the gelled extracts is equivalent to that of the liquid extract after 6 months of storage at 25 and 40°C. Gelling an extract according to the invention under the conditions of the study does not alter its activity potential.

[0124] Example 7: Formulation study of gelled extracts according to the invention

[0125] The feasibility study of incorporating a gelled extract of Withania somnifera according to the invention with 1% of k-carrageenan was carried out in two different formulations.

[0126] The first is a simple emulsion not involving gelling agents. The objective was not to interfere with the polysaccharides already added to gel the extract.

[0127] The tested formula is described in Table 3(a). A control emulsion not containing extract was also prepared for comparison. [Tables 3a] Component Percentage Demineralized Water 76 Decanex 2004 FG 15 Emulium® Delta MB 6 PE 9010 1 Gelled NaDES extract according to the invention 2

[0128] The second formulation studied is a serum with a more complex composition and includes gelling agents. The tested formula is described in Table 3(b). A control serum not containing the extract was also prepared for comparison. [Tables 3b] Component Percentage Demineralized water 5535 Propanediol 15 Vanatural 7 Xanthan gum 0.2 Glycerin 12 Emulium® dolcea MB 2.5 Cetiol ultimate 10 PE9010 0.7 Citric acid 0.25 Gelled NaDES extract according to the invention 2

[0129] The incorporation into the formulas of gelled and non-gelled extracts of Withania somnifera is carried out at the end of the preparation of the formula.

[0130] No implementation issues were identified during these tests. All tests for preparing cosmetic compositions (emulsions and serums) resulted in smooth, creamy white emulsions or fluid, homogeneous white serums. The pH and viscosity measurements of the emulsions and serums obtained were all of the same order of magnitude.

[0131] Microscopic observation of the formulas obtained was then carried out on the day of preparation and after 1 month of storage at 25°C. The results obtained are presented in comparison with the control formulations without extract in [Fig.7].

[0132] In both types of formulation studied, homogeneous emulsions with regularly sized globules are obtained after 1 month of storage at 25°C.

[0133] The gelled extracts according to the invention can be incorporated into a cosmetic formulation and do not require any additional steps for their preparation. The macroscopic and microscopic appearance of the emulsions and serums obtained is similar to that obtained with the ungelled extract. Thus, the presence of polysaccharides and the physical form (viscoelastic liquids and / or physical gels) do not in any way hinder the possibility of incorporating the extracts according to the invention into cosmetic formulations.< / c>

Claims

Demands

1. Plant extract capable of being obtained by a process of extraction of plant material comprising the following steps: - solid-liquid extraction by contacting the plant material with an extraction solvent, - solid / liquid separation of the extract obtained, - recovery of the liquid phase of the extract characterized in that the extraction solvent consists of a mixture of fructose, glycerin and water, and in that the liquid phase of the extract further contains at least one exogenous polysaccharide.

2. Extract according to claim 1, characterized in that the exogenous polysaccharide is of plant, marine or microbial origin and is not chemically modified.

3. Extract according to claim 2, characterized in that the polysaccharide is selected from the group comprising natural gums, carrageenans, alginates, xylans, pectins, hyaluronic acid or agarose derivatives used alone or in mixture.

4. Extract according to claim 3, characterized in that the natural gums are chosen from the group comprising guar, carob, xanthan gum, acacia.

5. Extract according to claim 3, characterized in that the agarose derivatives are selected from the group comprising agaropectins and agar-agar.

6. Extract according to any one of the preceding claims, characterized in that at least one polysaccharide represents less than 5%, advantageously between 0.5 and 2% by weight of the extract.

7. Extract according to claim 1, characterized in that the solvent consists of a mixture of fructose, glycerin and water in molar proportions between 1:1:3 and 1:1:7, preferably in molar proportions of about 1:1:

5.

8. Extract according to any one of the preceding claims characterized in that the viscosity of said extract measured for shear rates between 0.01 and 100 s 1 is greater than 250 Pa.s, preferably between 275 and 10000 Pa.s.

9. Extract according to any one of the preceding claims, characterized in that said extract has an elastic modulus G' greater than the modulus viscous G”.

10. Extract according to claim 1, characterized in that the solvent consists of a mixture of fructose, glycerin and water in molar proportions of about 1:1:5 and in that the polysaccharide is k-carrageenan.

11. A method for manufacturing a plant extract according to any one of the preceding claims, further comprising the following step: - stirring until a gelled extract is obtained.

12. Cosmetic and / or dermatological composition comprising the extract which is the subject of one of claims 1 to 9.

13. Composition according to claim 12, characterized in that the extract represents between 0.1% and 10%, preferably between 0.5% and 5% by weight of the composition.