Swertia japonica extract and cosmetic composition containing the same

Abstract

The present invention relates to a method of using supercritical CO 2 The invention relates to a Swertia japonica extract obtained by extracting an alcohol extract of Swertia japonica, and to a cosmetic composition containing the extract having an anti-aging effect on the skin.

Description

Technical Field

[0001] The present invention relates to a Swertia chirata extract, a method for obtaining the extract, a cosmetic composition containing the extract, and various cosmetic uses thereof. Background Art

[0002] The skin is mainly composed of three layers, namely, from the surface, the epidermis, dermis and subcutaneous tissue.

[0003] The outer layer of the skin, the epidermis, is composed of keratinocytes (mostly), melanocytes (involved in skin pigmentation) and Langerhans cells. Its function is to protect the organism from the external environment and ensure its integrity, in particular to slow down the penetration of microorganisms or chemicals, as well as to prevent the evaporation of the water contained in the skin.

[0004] For this purpose, keratinocytes undergo a continuous directed maturation process during which the keratinocytes located in the basal layer of the epidermis form, in the final stage of their differentiation, keratinocytes, which are completely keratinized dead cells in the form of a cornified envelope composed of proteins and lipids (such as ceramides). During this differentiation process, intercorneal cells of the epidermal lipids are also formed, which are then organized in the form of a double layer (sheet) in the stratum corneum. Together with the above-mentioned cornified envelope, they participate in the barrier function of the epidermis.

[0005] As the skin ages, it becomes thinner, loses volume and elasticity, and its barrier function is impaired. The dermal epidermal junction is one of the preferred targets of skin aging. Its main function is to allow adhesion between the epidermis and the dermis to ensure adhesion and nutritional functions of the skin. These functions are mainly based on the effect of the extracellular matrix produced by keratinocytes. The matrix is ​​composed of the assembly of several macromolecules, including collagen, proteoglycans, glycosaminoglycans (including hyaluronic acid), elastin and structural glycoproteins. The effect of cell aging and environmental factors (such as UV radiation or pollution) will adversely change these extracellular matrix components. They will undergo enzymatic degradation, particularly by the effect of matrix metalloproteinases (MMPs); the matrix will no longer be able to correctly perform its function, which will result in a reduction in fragility and cell regeneration ability, and will result in wrinkles and fine lines on the skin.

[0006] The prevention of the extracellular matrix and its degradation, particularly by the action of enzymes such as MMPs, has become a preferred target for preventing and reducing skin aging.

[0007] There is therefore a real need to provide active agents capable of acting to maintain the function of the extracellular matrix and in particular to prevent its degradation, in order to combat the adverse changes caused by skin aging.

[0008] Furthermore, due to the growing consumer demand for natural products containing as few synthetic ingredients as possible, as well as the increasingly widespread regulatory restrictions affecting compounds derived from the chemical industry, it would be advantageous for such active agents to be derived from plant extracts.

[0009] There is also a need to find more environmentally friendly extraction methods that use recyclable and nontoxic solvents while allowing for the selective extraction of target molecules without degrading them. SUMMARY OF THE INVENTION

[0010] Swertia is a plant of the genus Swertia, which is a genus belonging to the Gentianaceae family and containing about 150 species. Swertia is particularly used in traditional medicine in India, Bhutan and Nepal, where it originates. Its root is considered the most biologically active part of the plant and is used to treat various conditions such as fever, malaria, asthma, certain liver pathologies, diabetes or certain types of mental disorders.

[0011] Completely surprisingly, the authors of the present invention have successfully demonstrated that Swertia japonica extracts with significant anti-aging and barrier function protection properties can be obtained by subjecting the alcohol extracts of Swertia japonica to an extraction step with supercritical CO2. The inventors have particularly demonstrated that these extracts can inhibit, on the one hand, the inflammatory and degradation processes of the extracellular matrix mediated by epidermal keratinocytes, and, on the other hand, can stimulate the lipid metabolism of keratinocytes and stimulate the synthesis of extracellular matrix components. Therefore, these extracts can be used to prevent / slow down skin aging caused by destruction and degradation of the extracellular matrix, and can also be used to improve the barrier function and hydration of the skin.

[0012] Furthermore, the Swertia japonica extracts according to the invention are advantageously compatible with all pharmaceutical presentation forms: not only can they be used in cosmetic compositions such as creams or gel-creams, but they can also advantageously be introduced into compositions comprising only an aqueous phase, such as lotions, or compositions comprising only a non-aqueous phase, for example in the form of an oil.

[0013] Therefore, according to a first aspect, the present invention relates to a method for preparing a Swertia japonica extract, comprising the step of extracting an alcoholic extract of Swertia japonica with supercritical CO2 at a temperature of 40-80°C, preferably 50-70°C and at a pressure of 20-60 MPa, preferably 25-35 MPa.

[0014] The subject of the present invention is also a Swertia japonica extract obtained by this process, and a cosmetic composition comprising such a Swertia japonica extract in a physiologically acceptable medium.

[0015] Finally, a subject of the present invention is also the non-therapeutic cosmetic use of an extract of Swertia japonica as described above for preventing and / or reducing skin ageing, but also for hydrating the skin and / or improving the barrier function of the skin. DETAILED DESCRIPTION OF THE INVENTION

[0017] Swertia japonica

[0018] Swertia chirayta, also known as Swertia chirayta, Swertia chirayita or chiretta, is an herbaceous plant belonging to the Gentianaceae family and the genus Swertia. It is found in the Himalayan plateau, especially in India, Nepal and Bhutan. It is an erect annual / biennial herb, 60-150 cm tall, with a stem that is cylindrical from its base to its middle, and quadrilateral in its upper part. Its stem is orange-brown, or even purple-blue, with a yellow core. Its leaves are lanceolate, opposite, sessile, pointed, about 4-10 cm long. It has many flowers, which are tetrameric and are violet-colored yellow-green.

[0019] The Swertia japonica extract according to the invention is obtained from the whole plant, that is to say from the parts of the plant including the flowers, leaves, stems and roots.

[0020] Method for preparing Swertia japonica extract

[0021] The method for preparing the Swertia japonica extract according to the present invention comprises the step of extracting the alcohol extract of Swertia japonica with supercritical CO2 at a temperature of 40-80°C, preferably 50-70°C and at a pressure of 20-60 MPa, preferably 25-35 MPa.

[0022] The Applicant has in fact demonstrated that by subjecting the alcoholic extract of Swertia japonica to a second extraction using supercritical CO2, it is possible to obtain an extract having significant anti-aging and barrier function stimulating properties.

[0023] The extraction with supercritical CO2 is carried out at a temperature of 40-80°C, preferably 50-70°C, for example 60°C and at a pressure of 20-60 MPa, preferably 25-35 MPa, for example 30 MPa.

[0024] In the context of the present invention, it should be noted that the value ranges of "A"-"B", such as the temperature of 40-80°C above, include all values ​​of AB, including the endpoints. Thus, the step of extraction with supercritical CO2 according to the present invention can be carried out at any temperature value of 40-80°C, but can also be carried out at 40 or 80°C. This applies to all value ranges disclosed in the context of the present invention.

[0025] According to a preferred embodiment, the CO2 flow rate is at least 150 g / min, preferably 200 g / min.

[0026] The extraction with supercritical CO2 is preferably carried out in the presence of an alcohol solvent. The alcohol solvent may be a monohydric alcohol containing 2-4 carbon atoms, preferably ethanol. According to a preferred embodiment, the extraction with supercritical CO2 is carried out in the presence of ethanol, preferably ethanol at 60°.

[0027] According to a specific embodiment, the alcohol solvent, preferably ethanol, is introduced in a content of 1-10% relative to the total weight of the mixture comprising supercritical CO2 and the alcohol solvent.

[0028] The advantages of extraction with supercritical CO2 are that it requires only a small amount of solvent consumption (supercritical CO2 as the main solvent is recycled), uses non-toxic solvents and is an environmentally friendly process.

[0029] In the step of extracting with supercritical CO2, an extraction solvent (comprising a mixture of supercritical CO2 and an optional alcohol solvent) is used, wherein the weight ratio of the extraction solvent to the alcohol extract is 40-150, preferably 75.

[0030] In the context of the present invention, an "alcoholic extract" subjected to an extraction step with supercritical CO2 is an extract that has been obtained by a step of extracting Swertia japonica with at least one alcoholic solvent and has therefore been subjected to an "alcohol extraction" step. The alcoholic solvent is as defined above. It can be the same or another alcoholic solvent relative to the step of extraction with supercritical CO2. According to a preferred embodiment, the alcoholic solvent used for the alcohol extraction step is ethanol, more preferably ethanol at 60°.

[0031] All parts of Swertia japonica can be extracted with an alcohol solvent in "fresh" form, that is to say within 48 hours, particularly within 24 hours, even more particularly within 12 hours after harvesting.

[0032] All parts of Swertia japonica can also be extracted in dry form. In this case, the fresh plant is dehydrated under mild conditions, at ambient temperature in the dark or in a ventilated dryer at a temperature of less than 35° C. The plant is preferably dried until a solid content of greater than 80%, preferably greater than 85%, is obtained.

[0033] It is also possible to grind all the parts of Swertia japonica to obtain a powder comprising particles with a size of less than 5 cm, preferably less than 2 cm.

[0034] All parts of the whole or ground Swertia japonica in fresh or dried form are subjected to at least one extraction step (alcohol extraction step) with at least one alcohol solvent to obtain the alcohol extract of Swertia japonica used in the context of the present invention. The plant / alcohol solvent ratio used for the alcohol extraction step is typically 1-10 (weight / weight), and the step lasts for at least 1 hour, preferably at least 2 hours, in particular at least 3 hours, and can be repeated once or twice. The alcohol extract obtained at the end of the alcohol extraction step is filtered, for example by sieving, to remove plant residues. The alcohol extract can be filtered, for example, at 100 μm, in particular 10 μm, preferably 1 μm.

[0035] The alcohol extract may also be decolorized, for example, after a filtering step. This step is intended to remove the pigment (mainly chlorophyll) present in the extract. Those skilled in the art know several methods for removing the pigment present in the plant extract. Decolorization may be carried out, for example, by contacting the extract with activated carbon. Once decolorization is carried out, the mixture is filtered to remove carbon residues.

[0036] Thus, the alcoholic extract of Swertia japonica is obtained after at least one alcohol extraction step of Swertia japonica and optionally a filtration and / or decolorization step, which will be extracted with supercritical CO2.

[0037] In a specific embodiment, the alcohol extract is combined with a carrier such as a polysaccharide (e.g., starch, maltodextrin or preferably cellulose) prior to extraction with supercritical CO. In this context, the polysaccharide is added to the alcohol extract in an amount of 50-70% by weight relative to the total weight of the mixture comprising the alcohol extract and the polysaccharide, and in an amount of 30-50% by weight relative to the total weight of the mixture comprising the alcohol extract and the polysaccharide (preferably cellulose).

[0038] According to this specific embodiment, the alcoholic solvent (preferably ethanol) present in the alcoholic extract + polysaccharide mixture can be removed typically by evaporation (for example by evaporation under vacuum) to obtain only a mixture of polysaccharides / dry extracts, that is to say containing 100% by weight of solids. Then, the mixture can be ground to obtain a polysaccharide / dry extract powder containing particles with a size of less than 2 cm, preferably less than 1 cm. According to this embodiment, in the context of the method of the present invention, the powder is subjected to a step of extraction with supercritical CO2.

[0039] Therefore, according to a specific embodiment, the method for preparing the Swertia japonica extract according to the present invention comprises the following steps:

[0040] a) extracting Swertia japonica with at least one alcohol solvent, preferably ethanol, preferably in powder form;

[0041] b) filtering the mixture obtained in a) to remove plant residues;

[0042] b') optionally, decolorizing the mixture obtained at the end of step b);

[0043] c) adding a polysaccharide, preferably cellulose, to the mixture thus obtained, to obtain a polysaccharide / dry extract mixture in an alcoholic solvent;

[0044] d) removing the alcohol solvent, preferably by evaporation;

[0045] e) grinding the dry extract / polysaccharide mixture obtained at the end of step d) to obtain a powder; and

[0046] f) extracting the powder obtained at the end of step e) with supercritical CO2 at a temperature ranging from 40 to 80°C, preferably from 50 to 70°C and at a pressure ranging from 20 to 60 MPa, preferably from 25 to 35 MPa.

[0047] The Swertia japonica extract obtained at the end of the extraction step with supercritical CO2 is the extract according to the invention.

[0048] The extract may also be processed and ultimately used for cosmetic purposes, so that it can be incorporated into a cosmetic composition. The processing is carried out by conventional methods known to those skilled in the art, for example by steps of dilution, combination with a cosmetic carrier, evaporation of the solvent or filtration.

[0049] Herein, the extract contained in the solvent used for extraction with supercritical CO 2 (ie the liquid phase obtained at the end of the step of extraction with supercritical CO 2 ) may be subjected to a filtration step, for example to 1 μm.

[0050] The extract may then be diluted in an oil, such as a vegetable oil or an esterified oil, such as caprylic / capric triglyceride or preferably 2-ethylhexyl palmitate, for example at 1%.

[0051] The alcohol solvent can be removed before or after dilution in the oil, for example by evaporation, preferably by evaporation under vacuum.

[0052] The extract diluted in oil may then be filtered again, for example to 1 μm, to remove insoluble matter and thus obtain the final extract.

[0053] According to this embodiment, the above method may therefore further comprise the following steps g) to i):

[0054] g) filtering the extract contained in the solvent used for extraction with supercritical CO2 and optionally removing the alcohol solvent, preferably by evaporation;

[0055] h) diluting the extract obtained at the end of step g) in an oil, preferably 2-ethylhexyl palmitate, and optionally removing the residual alcohol solvent, preferably by evaporation;

[0056] i) filtering the diluted extract obtained at the end of step h).

[0057] According to this embodiment, the method for preparing a Swertia japonica extract according to the present invention may thus comprise the following steps:

[0058] a) all parts of Swertia japonica previously dried and ground to a fineness of less than 2 cm were extracted twice by maceration in ethanol at 60° C. with a solvent / plant ratio of 10 / 1 for 2 h;

[0059] b) the extract thus obtained is subsequently sieved at 100 μm and then filtered to 1 μm to remove plant residues;

[0060] b') decolorizing the extract with 30% activated carbon relative to the dry extract and then filtering again at 1 μm to remove residual carbon;

[0061] c) adding cellulose to the extract to obtain a cellulose (40%) / dry extract (60%) mixture in ethanol;

[0062] d) subsequently evaporating off the ethanol to obtain only the cellulose / dry extract mixture;

[0063] e) subsequently grinding the cellulose / dry extract mixture to a fineness of less than 1 cm to obtain a powder;

[0064] f) subsequently extracting the resulting powder with a supercritical CO2 (95%) / ethanol (5%) mixture at 60°C, 500 bar (50 MPa) and a flow rate of 200 g / min until the weight ratio of the supercritical CO2 (95%) / ethanol (5%) mixture relative to the alcohol extract is 75;

[0065] g) filtering the obtained ethanol extract at 1 μm;

[0066] h) diluting the extract obtained at the end of step g) to 1% in 2-ethylhexyl palmitate and evaporating off the ethanol;

[0067] i) The extract was then filtered at 1 μm to remove insoluble matter and obtain the final extract (referred to herein as "Extract C1").

[0068] According to another embodiment, the residual powder obtained at the end of the supercritical CO2 extraction step containing polysaccharides (such as cellulose) and a portion of the Swertia japonica extract (i.e. the solid phase obtained at the end of the step of extraction with supercritical CO2) can be suspended in an alcohol solvent, preferably ethanol. The alcohol solvent is as defined above and can be the same or another alcohol solvent relative to the alcohol solvent used for the alcohol extraction step and / or the step of extraction with supercritical CO2.

[0069] The mixture containing the residual powder suspended in the alcohol solvent may then be filtered, for example to 1 μm, to remove the cellulose.

[0070] The extract may then be diluted, for example to 1%, in a glycol such as caprylyl glycol, pentylene glycol or preferably propylene glycol.

[0071] The alcohol solvent can be removed before or after dilution in the diol, for example by evaporation, preferably by evaporation under vacuum.

[0072] The extract diluted in diol may then be filtered again, for example to 1 μm, to remove insoluble matter and thus obtain the final extract.

[0073] According to this alternative embodiment, the method comprising the above steps a)-f) may therefore further comprise the following steps g1)-j1):

[0074] g1) dissolving the residual powder obtained at the end of step f) in an alcoholic solvent, preferably ethanol;

[0075] h1) filtering the mixture obtained at the end of step g1) and optionally removing the alcoholic solvent, preferably by evaporation;

[0076] i1) diluting the extract obtained at the end of step h1) in a glycol, preferably propylene glycol, and optionally removing residual alcohol solvent, preferably by evaporation;

[0077] j1) filtering the diluted extract obtained at the end of step i1).

[0078] According to this alternative embodiment, the method for preparing a Swertia japonica extract according to the present invention may therefore comprise the following steps:

[0079] a) all parts of Swertia japonica previously dried and ground to a fineness of less than 2 cm were extracted twice by maceration in ethanol at 60° C. with a solvent / plant ratio of 10 / 1 for 2 h;

[0080] b) the resulting extract was subsequently sieved at 100 μm and then filtered to 1 μm to remove plant residues;

[0081] b') decolorizing the extract with 30% activated carbon relative to the dry extract and then filtering again at 1 μm to remove residual carbon;

[0082] c) adding cellulose to the extract to obtain a cellulose (40%) / dry extract (60%) mixture in ethanol;

[0083] d) subsequently evaporating off the ethanol to obtain only the cellulose / dry extract mixture;

[0084] e) then, grinding the cellulose / dry extract mixture to a fineness of less than 1 cm to obtain a powder;

[0085] f) subsequently extracting the resulting powder with a supercritical CO2 (95%) / ethanol (5%) mixture at 60°C, 500 bar (50 MPa) and a flow rate of 200 g / min until the weight ratio of the supercritical CO2 (95%) / ethanol (5%) mixture relative to the alcohol extract is 75;

[0086] g1) then, recovering the residual powder present at the end of step f) and returning it to the ethanol solution under stirring at 45° C.;

[0087] h1) then, the mixture was filtered at 1 μm to remove cellulose;

[0088] i1) The extract was then diluted to 1% in propylene glycol and the ethanol was evaporated under vacuum;

[0089] j1) The extract was then filtered at 1 μm to remove insoluble matter and obtain the final extract (referred to herein as "Extract C2").

[0090] Swertia japonica extract

[0091] The present invention, which is the subject of this application, also covers the Swertia japonica extract obtained by the above-mentioned process.

[0092] Cosmetic composition

[0093] A subject of the present invention is also a cosmetic composition comprising, in a physiologically acceptable medium, at least one Swertia japonica extract obtained according to the process of the invention.

[0094] In addition to the above-mentioned extracts, the compositions used according to the invention generally comprise a physiologically acceptable and preferably cosmetically acceptable medium, i.e. a medium which is suitable for contact with human skin without any risk of toxicity, incompatibility, instability or allergic reaction and in particular does not cause unpleasant sensations (redness, tightness, stinging).

[0095] Advantageously, the cosmetic or dermatological composition may be in the form of a powder, emulsion, microemulsion, nanoemulsion, suspension, solution, lotion, cream, aqueous or hydro-alcoholic gel, foam, slurry, solution or dispersion for an aerosol or a dispersion of lipid vesicles.

[0096] In the case of an emulsion, it may be a water-in-oil or an oil-in-water emulsion.

[0097] The cosmetic or dermatological composition according to the invention may also contain a solvent selected according to the respective ingredients and application form.

[0098] As examples, mention may be made of water (preferably demineralized water or floral water) or alcohols (such as ethanol).

[0099] In addition to the extract according to the present invention, the cosmetic composition may also contain at least one additive commonly used in the art, such as at least one compound selected from the group consisting of emollients or humectants, gelling agents and / or thickeners, surfactants, oils, active agents, dyes, preservatives, antioxidants, organic or inorganic powders, sunscreens and fragrances:

[0100] - One or more humectants, for example polyols (glycerol, diglycerol, propylene glycol, caprylyl glycol, pentylene glycol, hexylene glycol), sugars, glycosaminoglycans (eg hyaluronic acid) and their salts and esters; and polyquaterniums (eg Lipidure PMB).

[0101] The humectant is present in the composition at a level of about 0.1-30%, preferably 0.005-10%, based on the total weight of the composition.

[0102] - one or more emollients which may be chosen, for example, from esters such as jojoba esters, fatty acid esters of fatty alcohols (octyldodecyl myristate, triethylhexanoin, dicaprylyl carbonate, isostearyl isostearate, caprylic / capric triglyceride), shea butters such as shea butter (butyrospermum parkii butter extract, shea butter ethyl esters, sold under the trade names Lipex Sheasoft, Lipex Shea-U, Lipex Shea, Lipex Shealight, Lipex Shea Tris) or moringa butter (moringa oil / hydrogenated moringa oil esters), waxes (Acacia decurrens flower wax & Helianthus annuus seed beeswax (seed wax), C10-18 triglycerides), vegetable oils, vegetable squalane, alkanes (undecane, tridecane).

[0103] The emollient is present in the composition at a level of about 0.1-30%, preferably 0.5-10%, based on the total weight of the composition.

[0104] one or more aqueous phase gelling agents and / or aqueous phase thickeners, for example chosen from cellulose-based derivatives, gums of vegetable origin (guar, locust bean gum, alginates, carrageenan, pectin), or gums of microbial origin (xanthan gum), clays (laponite), hydrophilic or amphiphilic crosslinked or non-crosslinked homopolymers and copolymers of acryloylmethylpropanesulfonic acid (AMPS) and / or acrylamide and / or acrylic acid and / or acrylates or esters (sold under the names Aristoflex AVC, Aristoflex AVS, Aristoflex HMB, Simulgel NS, Simulgel EG, Simulgel 600, Simulgel 800, Pemulen, Carbopol, Sepiplus 400, Seppimax Zen, Sepiplus S, Cosmedia SP).

[0105] The gelling agent and / or thickening agent will be present in the composition at a level of about 0.1% to 10% by weight of the total composition.

[0106] one or more surfactants, for example lecithin, polyglycerol derivatives, sugar derivatives (glycosides or xylosides derivatives sold under the names Montanov 68, Montanov 202, Montanov 82, Montanov L, Easynov), phosphates (C20-22 alkyl phosphates sold under the name Sensanov WR).

[0107] The surfactant will be present in an amount of about 0.1-8% by weight, preferably 0.5-3% by weight, relative to the total weight of the composition.

[0108] one or more active agents of natural biotechnological or synthetic origin that are biologically active and effective on the skin via biological sites, for example chosen from vitamins (such as vitamin C) and their derivatives (ascorbyl glucoside, 3-O-ethyl ascorbic acid, ascorbyl tetraisopalmitate), vitamin A and its derivatives, vitamin E and its derivatives, vitamin B3 or niacinamide, panthenol, trace elements, allantoin, adenosine, peptides (palmitoyl tetrapeptide-7, palmitoyl tripeptide-1, palmitoyl pentapeptide-4, acetyl dipeptide-1 hexadecyl ester, acetyl tetrapeptide-5, sold under the names NP Rigin, Matrixyl 3000, Idealift, Eyeseryl), plant extracts (Glycyrrhiza glabra extract, Centella asiatica leaf extract, rye seed extract), yeast extracts, alpha-hydroxy acids (such as glycolic acid) or lactic acid, tranexamic acid and its derivatives (such as hexadecyl tranexamate), etc.

[0109] The active agent will be present in the composition at a level of about 0.1-10% by weight of the total composition.

[0110] Other additives usually used in cosmetics may also be present in the composition according to the invention, in particular preservatives, antioxidants or fragrances known in the art.

[0111] A person skilled in the art is able to choose from all these optional additives the nature and the content of those to be added to the composition so that said composition retains all its properties.

[0112] Non-therapeutic cosmetic use of the Swertia japonica extract according to the present invention

[0113] The present invention also provides for the non-therapeutic cosmetic use of an extract of Swertia japonica according to the invention for preventing and / or reducing skin ageing.

[0114] In this embodiment, the extract or composition is applied to deleteriously degenerated but non-pathological skin.

[0115] A subject of the present invention is also the non-therapeutic cosmetic use of an extract of Swertia japonica according to the invention as hydrating and / or soothing agent for hydrating the skin and / or improving the barrier function of the skin.

[0116] Furthermore, a subject of the present invention is the non-therapeutic cosmetic use of an extract of Swertia japonica according to the invention as an agent for inhibiting the activity of matrix metalloproteinases (MMPs).

[0117] Finally, the present invention also provides for the non-therapeutic cosmetic use of an extract of Swertia japonica according to the invention as an agent for stimulating the expression of genes encoding components of the extracellular matrix, in particular laminins and proteoglycans.

[0118] The invention will now be illustrated by the following non-limiting examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0119] Figure 1 Graph showing biological pathways modulated by 0.25% Swertia japonica extract C1 in normal human epidermal keratinocytes after 48 hours of treatment.

[0120] Figure 2 Graph showing biological pathways modulated by 0.25% Swertia japonica extract C2 in normal human epidermal keratinocytes after 48 hours of treatment. DETAILED DESCRIPTION

[0121] Example 1: Preparation and characterization of Swertia japonica extract

[0122] > Extract 1 (Extract "C1" or "PFAC1") was obtained by the following preparation method:

[0123] a) all parts of Swertia japonica previously dried and ground to a fineness of less than 2 cm were extracted twice by maceration in ethanol at 60° C. with a solvent / plant ratio of 10 / 1 for 2 h;

[0124] b) the resulting extract was subsequently sieved at 100 μm and then filtered to 1 μm to remove plant residues;

[0125] b') decolorizing the extract with 30% activated carbon relative to the dry extract and then filtering again at 1 μm to remove residual carbon;

[0126] c) adding cellulose to the extract to obtain a cellulose (40%) / dry extract (60%) mixture in ethanol;

[0127] d) subsequently evaporating off the ethanol to obtain only the cellulose / dry extract mixture;

[0128] e) subsequently grinding the cellulose / dry extract mixture to a fineness of less than 1 cm to obtain a powder;

[0129] f) subsequently extracting the powder obtained with a supercritical CO2 (95%) / ethanol (5%) mixture at 60°C, at 500 bar (50 MPa) at a flow rate of 200 g / min, until the powder can no longer be extracted;

[0130] g) filtering the obtained ethanol extract at 1 μm;

[0131] h) diluting the extract to 1% in 2-ethylhexyl palmitate and then leaving it at 4° C. overnight and evaporating the ethanol;

[0132] i) The extract was then filtered at 1 μm to remove insoluble matter and obtain the final extract.

[0133] After analysis, it was determined that Extract 1 contained 0.053% by weight of xanthones, including 0.015% of norswertianin, 0.006% of swertianin, 0.002% of bellidin, and 0.03% of hydroxyxanthone derivatives. Extract 1 also contained 0.03% by weight of oleanolic acid / ursolic acid (triterpenes). The extract did not contain any detectable swertiamarin.

[0134] The extract is an oily extract rich in non-polar molecules. Therefore, it can be advantageously incorporated into oily / non-aqueous compositions.

[0135] > Extract 2 (Extract "C2" or "PFAC2") was obtained by the following preparation method:

[0136] a) all parts of Swertia japonica previously dried and ground to a fineness of less than 2 cm were extracted twice by maceration in ethanol at 60° C. with a solvent / plant ratio of 10 / 1 for 2 h;

[0137] b) the resulting extract was subsequently sieved at 100 μm and then filtered to 1 μm to remove plant residues;

[0138] b') decolorizing the extract with 30% activated carbon relative to the dry extract and then filtering again at 1 μm to remove residual carbon;

[0139] c) adding cellulose to the extract to obtain a cellulose (40%) / dry extract (60%) mixture in ethanol;

[0140] d) subsequently evaporating off the ethanol to obtain only the cellulose / dry extract mixture;

[0141] e) subsequently grinding the cellulose / dry extract mixture to a fineness of less than 1 cm to obtain a powder;

[0142] f) subsequently extracting the powder obtained with supercritical CO2 (95%) / ethanol (5%) at 60°C, 500 bar (50 MPa) and a flow rate of 200 g / min until the powder can no longer be extracted;

[0143] g1) then, recovering the residue present at the end of step f) and returning it to the ethanol solution under stirring at 45° C.;

[0144] h1) filtering the mixture at 1 μm to remove cellulose;

[0145] i1) The dry extract is then diluted to 1% in propylene glycol and the ethanol is evaporated;

[0146] j1) The extract was then filtered at 1 μm to remove soluble matter and obtain the final extract.

[0147] After analysis, it was determined that Extract 2 contained 0.134% by weight of xanthones, including 0.052% mangiferin, 0.006% norswertianin, 0.039% 3-O-demethylswertipunicoside, 0.001% bellidin, 0.019% dixanthenone, and 0.002% hydroxyxanthenone derivatives. Extract 2 also contained 0.035% swertiamarin, 0.282% by weight sugars / polyols, 0.038% by weight oleanolic acid / ursolic acid (triterpenoids), 0.024% by weight minerals, and less than 0.001% amygdalin.

[0148] The extract is a hydro-alcoholic extract rich in polar molecules. It can therefore be advantageously incorporated into aqueous compositions.

[0149] >Comparative ethanol extract (extract "EtOH") was obtained by the following preparation method:

[0150] a) all parts of Swertia japonica previously dried and ground to a fineness of less than 2 cm were extracted twice by maceration in ethanol at 60° C. with a solvent / plant ratio of 10 / 1 for 2 h;

[0151] b) the resulting extract was subsequently sieved at 100 μm and then filtered to 1 μm to remove plant residues;

[0152] b') decolorizing the extract with 30% activated carbon relative to the dry extract and then filtering again at 1 μm to remove residual carbon;

[0153] i1) The extract was then diluted in propylene glycol to obtain a mixture of propylene glycol (90%) / dry extract (10%), and the ethanol was evaporated off.

[0154] After analysis, the comparative extract ethanol was determined to contain 0.156 wt% xanthone and 0.043 wt% triterpenes.

[0155] Example 2: Activity of Swertia japonica extracts C1 and C2

[0156] plan:

[0157] Normal human epidermal keratinocytes from three different donors (27 to 34 years old) were seeded into 6-well plates and cultured in KGM-2 medium (supplied by Lonza) at 37°C, 5% CO2 for 72 hours. The cells were then incubated with 0.5% or 0.25% of Swertia japonica extract C1 or C2 or without incubation (control) for 48 hours. Each condition was performed in duplicate. Total RNA was extracted using the RNeasy 96 plate extraction kit (supplied by Qiagen) according to the supplier's recommendations. The amount and quality of RNA were evaluated by Multiskan G0 (supplied by ThermoFischer). Complementary DNA was synthesized and Transcriptome was analyzed on GeneChip Human Transcriptome Array 2.0 chip. Ingenuity Pathway Analysis software ( Qiagen) performs bioinformatics analysis of genes whose expression is regulated by at least 2-fold. The software collects information on molecular interactions, biological networks, and canonical pathways in an intelligent knowledge database.

[0158] result:

[0159] Swertia japonica extracts C1 and C2 showed different gene regulation profiles in epidermal keratinocytes.

[0160] After 48 hours of treatment, each of the two Swertia japonica extracts modulated gene expression in epidermal keratinocytes (183-636 genes). At a concentration of 0.25%, the extracts modulated 2-2.5 times more genes compared to the 0.5% concentration. The Venn diagram showed that the two extracts co-regulated a small number of genes, with only 35 common genes at a concentration of 0.5% and 158 common genes at a concentration of 0.25% (data not shown).

[0161] use Software, analysis of biological networks regulated by the two extracts revealed different mappings. These results suggest that Swertia japonica extracts C1 and C2 act through different biological mechanisms. Swertia japonica extract C1 preferentially acts by inhibiting biological pathways, while Swertia japonica extract C2 preferentially activates biological pathways in keratinocytes.

[0162] Swertia japonica extract C1 inhibits epidermal keratinocyte-mediated inflammation and extracellular matrix degradation processes.

[0163] Analysis of biological pathways and genes regulated by Swertia japonica extract C1 showed that the extract was able to reduce interleukin IL-8-mediated inflammatory responses (Figure 1, asterisks) and inhibit the expression of metalloproteinases MMP1 (FC=-146), MMP3 (FC=-22), MMP9 (FC=-4) and MMP10 (FC=-21) in epidermal keratinocytes responsible for extracellular matrix degradation, compared with untreated controls. These properties imply that Swertia japonica extract C1 has anti-inflammatory and anti-aging effects on the skin.

[0164] Swertia japonica extract C2 stimulates lipid metabolism in keratinocytes and promotes the synthesis of extracellular matrix components.

[0165] Analysis of biological pathways and genes regulated by Swertia japonica extract C2 revealed that the extract was able to stimulate biological pathways involved in lipid metabolism in epidermal keratinocytes (LXR / RXR and PPAR pathways, Figure 2 ). Likewise, Swertia japonica extract 1411PFA C2 was able to stimulate the expression of many genes encoding extracellular matrix components (laminin and proteoglycans) or fibroblast activating factor (see Table 1 below).

[0166]

[0167] Table 1: Genes expressed in normal human epidermal keratinocytes stimulated by 0.25% Swertia japonica extract C2 after 48 hours of treatment

[0168] Therefore, the extract has anti-aging properties due to its activity in stimulating the synthesis of extracellular matrix components, but also has skin lipid barrier strengthening properties to maintain and improve the hydration of the skin.

[0169] The Swertia japonica extract according to the invention has skin anti-aging activity, which is mediated by complementary activities, either by inhibition of MMPs or by synthesis of matrix components, respectively. The comparative extract EtOH does not have these specific properties.

[0170] Example 2: Cosmetic composition

[0171] The following compositions can be routinely prepared by one skilled in the art. The amounts shown below are expressed as weight percentages. Ingredients are identified according to INCI names.

[0172] A-Oil / Water Gel Emulsion

[0173]

[0174]

[0175] B-Oil / Water Cream Emulsion

[0176]

[0177] C-Lotion

[0178] INCI name (%w / w) glycerin 1-15 Propylene glycol 1-5 Butanediol 1-5 Pentylene glycol 0.1-5 Caprylyl glycol 0.01-2 Polyquaternium-51 0.1-2 Tuberose 0.1-2 Sodium Hyaluronate 0.01-0.5 Swertia japonica extract C2 according to the present invention 0.001-10 water Qs 100

[0179] D-Oil

[0180]

[0181] These compositions can be applied to the skin daily, in the morning and / or evening.

Claims

1. A method for preparing a Swertia japonica extract, comprising the following steps: -a) extracting Swertia japonica with at least one alcohol solvent to obtain an alcohol extract of Swertia japonica; - b) filtering the mixture obtained in a) to remove plant residues; -c) adding a polysaccharide to the mixture thus obtained, so as to obtain a polysaccharide / dry extract mixture in an alcohol solvent; -d) removing the alcohol solvent; -e) grinding the dry extract / polysaccharide mixture obtained at the end of step d) to obtain a powder; - f) extracting the powder obtained at the end of step e) with supercritical CO2 at a temperature ranging from 40 to 80°C, a pressure ranging from 20 to 60 MPa and in the presence of an alcoholic solvent.

2. The method according to claim 1, wherein the alcohol solvent is introduced in an amount of 1-10% relative to the total weight of the mixture comprising supercritical CO2 and the alcohol solvent.

3. The method according to claim 1, characterized in that It also includes the following steps: g) filtering the extract contained in the solvent used for extraction with supercritical CO2; h) diluting the extract obtained at the end of step g) in oil; i) filtering the diluted extract obtained at the end of step h).

4. The method according to claim 1, characterized in that: It also comprises the following steps: g1) dissolving the residual powder obtained at the end of step f) in an alcohol solvent; h1) filtering the mixture obtained at the end of step g1); i1) diluting the extract obtained at the end of step h1) in glycol; j1) filtering the diluted extract obtained at the end of step i1).

5. Swertia japonica extract, characterized in that It is obtained by the method according to any one of claims 1-4.

6. A cosmetic composition comprising at least one Swertia japonica extract according to claim 5 in a physiologically acceptable medium.

7. Non-therapeutic cosmetic use of the Swertia japonica extract according to claim 5 for preventing and / or reducing skin aging.

8. Non-therapeutic cosmetic use of the Swertia japonica extract according to claim 5 for hydrating the skin and / or improving the skin barrier function.

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