Cosmetic use of an extract of immortelle as a skin lightening agent

Abstract

The present invention relates to the cosmetic use of an extract of immortelle of the species Helichrysum italicum, containing flavonol heterosides of which the ring B is dihydroxylated, applied topically to the skin, as an agent for whitening the skin and / or lightening the complexion and / or for making the colour of the skin uniform and / or reducing or preventing the appearance of pigment spots, characterized in that the extract of immortelle contains at least 20% by weight of terpenes, relative to the total amount of volatile compounds present in said extract, of which less than 90% by weight are oxygenated terpenes, relative to the total amount of volatile terpenes present in said extract.

Description

[0001] Cosmetic use of immortelle extract as a skin lightening agent

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the cosmetic use of a particular immortelle extract as a skin lightening agent.

[0004] BACKGROUND OF THE INVENTION

[0005] The mechanism of skin pigmentation is a complex process of melanin production by melanocytes, which are specialized cells located in the basal layer of the epidermis. This mechanism schematically involves the following main steps:

[0006] Tyrosine — > Dopa — > Dopaquinone — > Dopachrome — > Melanin, catalyzed by tyrosinase, which is the essential enzyme involved in this series of reactions.

[0007] Skin color is primarily determined by the nature and concentration of melanin produced by melanocytes. Melanocytes can be activated by internal or external stimuli to produce melanin in specialized lysosome-like organelles called melanosomes. After maturation, perinuclear melanosomes are transported along microtubules and the actin cytoskeleton to the periphery of melanocyte dendrites. The melanosomes, which contain melanin, are then transferred to adjacent keratinocytes.

[0008] Any alteration of any step in this complex process can lead to skin pigmentation disorders. In particular, an increase in the number of active melanocytes, and / or an increase in melanin production, and / or an increase in the transfer of melanosomes from melanocytes to keratinocytes can lead to skin hyperpigmentation.

[0009] Thus, environmental, genetic and / or hormonal factors can modulate the quantity, type and distribution of melanin in the skin and / or hair, with significant cosmetic and psychological consequences. Darker and / or more colored spots can thus appear on the skin and more specifically on the hands of certain people in the sun. Other types of regional hyperpigmentation due to melanocytic hyperactivity are idiopathic melasmas, occurring during pregnancy ("pregnancy mask" or chloasma) or estrogen-progestin contraception. Conversely, hypopigmentation of the skin can be observed in cases of sun exposure of scars or in the case of certain leukodermas such as vitiligo. In these situations, if it is not possible to repigment the damaged skin, the areas of residual normal skin are depigmented to give the entire skin a uniform white shade.

[0010] The use of harmless topical depigmenting substances with good efficacy is particularly sought after in order to treat all these pigmentation defects. A substance is recognized as whitening or depigmenting if it acts directly on the vitality of the epidermal melanocytes where melanogenesis takes place, and / or if it interferes with one of the stages of melanin biosynthesis, either by inhibiting one of the enzymes involved in melanogenesis, in particular tyrosinase, or by intercalating as a structural analogue of one of the chemical compounds in the melanin synthesis chain, a chain which can then be blocked and thus ensure depigmentation, and therefore lightening of the skin.

[0011] To treat these hyperpigmentation problems, various cosmetic active ingredients are currently used, such as vitamin C and its derivatives, arbutin, azelaic acid, glycolic acid, n-butylresorcinol (or rucinol), hexylresorcinol, and glutathione and its derivatives. These compounds have different modes of action, including inhibiting tyrosinase activity, reducing the amount of melanin formed, or stimulating the elimination of melanin within keratinocytes. However, some of these compounds can cause side effects such as burns, erythema, and dry skin.

[0012] There is therefore a need for a new whitening agent for human skin that is as effective as those known, but does not have their drawbacks, i.e., one that is non-irritating, non-toxic and / or non-allergenic to the skin. In this context, it has already been proposed to use various immortelle extracts as whitening agents, in particular an extract obtained by extraction, using a solvent such as ethanol, of the aerial parts of Helichrysum gymnocephalum (DC) Humbert. This extract is characterized by the presence of monoterpene derivatives of chalcone or dihydrochalcone, in particular gymnochalcone (FR2970416). We can also cite document WO 2007 / 015232 which suggests using an (undefined) Helichrysum arenarium extract in a process for removing scars and skin pigmentation, as well as document CN111973544 which reports the depigmenting effect of a hydroglycolic extract of Helichrysum bracteatum.It has also been suggested to use a combination of several different immortelle extracts for its anti-aging properties, as well as its ability to reduce pigment spots (FR3003167). Finally, patent application WO 2019 / 086602 suggests that a subcritical water extract of the flowering tops of Helichrysum italicum could have depigmenting properties and be used as an anti-spot cosmetic active ingredient.

[0013] The Applicant has now demonstrated, quite surprisingly, that another immortelle extract, already known for its properties of protecting the skin against oxidative stress and restoring the skin barrier (FR 3 057 166), exhibited good depigmenting activity, even at low concentrations, while being well tolerated. This extract differs clearly from that described in application WO 2019 / 086602, whether by its production process or by its chemical composition, as demonstrated in the Examples below.

[0014] SUMMARY OF THE INVENTION

[0015] The invention specifically relates to the cosmetic use of an extract of immortelle of the species Helichrysum italicum, containing flavonol heterosides whose B ring is dihydroxylated, applied topically to the skin, as a skin whitening agent and / or lightening the complexion and / or for homogenizing the color of the skin and / or reducing or preventing the appearance of pigment spots, characterized in that the immortelle extract contains at least 20% by weight of terpenes, relative to the total quantity of volatile compounds present in said extract, including less than 90% by weight of oxygenated terpenes, relative to the total quantity of volatile terpenes present in said extract.

[0016] It also relates to a cosmetic process for whitening the skin and / or lightening the complexion and / or for homogenizing the color of the skin and / or reducing or preventing the appearance of pigment spots, comprising the topical application to the skin of an extract of immortelle of the species Helichrysum italicum as defined above.

[0017] DETAILED DESCRIPTION

[0018] The present invention uses an extract of immortelle from the species Helichrysum italicum, preferably of Corsican origin, containing flavonol heterosides whose B cycle is dihydroxylated.

[0019] Flavonoids are a class of polyphenols containing the following skeleton:

[0020] They can themselves be subdivided into different categories depending on the carbon of the C ring to which the B ring is attached, the presence or absence of one or more unsaturations on the C ring and / or an oxo group in position 4 and / or a hydroxyl group in position 3 of the C ring.

[0021] Flavonols are a class of flavonoids that specifically include the following structural skeleton:

[0022] These include unsubstituted B-ring flavonols such as baicalein, mono-hydroxy B-ring flavonols such as kaempferol, and di-hydroxy B-ring flavonols such as quercetin and quercetagetin.

[0023] The immortelle extract used according to the invention contains heterosides of such dihydroxylated flavonols on the B ring. It can be obtained by extraction of the aerial parts, including in particular the flowering tops, of Helichrysum italicum using a mixture of deep eutectic solvents (or NaDES for "Natural Deep Eutectic Solvent").

[0024] NaDES solvents are mixtures of naturally occurring compounds with the property of having a single, defined melting point for a given composition; the eutectic mixture then exhibits certain physical properties that are those of pure substances, and in particular the property of having the same composition in the liquid phase and in the solid phase. The melting point of the eutectic is lower than the melting point of the mixture of the same substances in other proportions. The constituents of deep eutectic solvents are capable of forming strong hydrogen bonds together.

[0025] More particularly, by "NaDES" is meant, within the meaning of the invention, a mixture of compounds of natural origin capable of being used as a solvent and having a superstructure based on hydrogen interactions. Briefly, it is possible to determine that a given mixture actually has the superstructure of a NaDES by two-dimensional NMR spectroscopy, in particular by NOESY sequence (for Nuclear Overhauser Effect SpectroscopY). The presence of correlation spots (off-diagonal peaks) reflects a certain spatial proximity between the spins considered, and makes it possible to detect the superstructure of the NaDES. This superstructure as well as the methods for detecting it are well known to those skilled in the art, and have been precisely described in Dai Y. et al. (Analytica Chimica Acta, 766: 61-68, 2013), to which those skilled in the art may refer.

[0026] In a preferred embodiment of the invention, this mixture of solvents consists of: (a) at least two solvents respectively chosen from at least two distinct groups consisting of (i) carboxylic acids, (ii) glucose, (iii) fructose, (iv) sucrose, (v) lactose, (vi) trehalose, (vii) galactose, (viii) xylose, (ix) polyols and (x) nitrogen compounds consisting of choline, its inorganic salts and amino acids and (b) optionally water.

[0027] Examples of NaDES type solvents include those described in FR3036618, EP3922107, WO2011 / 155829.

[0028] Among the aforementioned solvents, the carboxylic acid is advantageously chosen from the group consisting of oxo-acids, such as pyruvic acid; mono- or polyhydroxy acids, such as malic, citric, lactic, tartaric, ascorbic, glucuronic and neuraminic acids; and dicarboxylic acids, such as oxalic, adipic, maleic, fumaric, succinic, aconitic, malonic and oxalic acids.

[0029] For its part, the polyol is preferably chosen from the group consisting of sugar alcohols such as mannitol, sorbitol, inositol, ribitol, galactitol, erythritol and xylitol; glycerin; butylene glycol; 1,3-propanediol; and propylene glycol.

[0030] Additionally, examples of amino acids are proline, alanine, glycine, trimethylglycine (betaine), arginine, and glutamine.

[0031] In a particularly preferred embodiment of the invention, the mixture of solvents forming the NaDES solvent consists of fructose, glycerin and water, preferably in a mass ratio of 50:25:25. Before its use in the preparation of the extract according to the invention, the NaDES solvent may itself be prepared by heating the mixture of solvents which constitute it, until its solid constituents melt, for example for a period of 0.5 to 3 hours at a temperature of 50 to 80°C, generally with stirring, to obtain a molten liquid, then optionally cooling to room temperature. In addition, the aerial parts of A'Helichrysum italicum may be previously ground and / or dried. The extraction can be carried out by bringing the plant, optionally dried and / or ground, into contact with the solvent NaDES at a temperature of 25°C to 95°C, for example 60 to 80°C, for a period of time ranging from 0.5 to 24 hours, for example 2 to 4 hours.The mass ratio of the optionally dried and / or ground plant to the NaDES solvent can range from 1:99 to 50:50, for example from 1:99 to 10:90. At the end of this extraction step, the liquid and the solid residue obtained can be separated by any technique known to those skilled in the art and in particular by centrifugation, decantation or pressing, preferably by centrifugal spinning. The crude extract thus obtained can then be clarified by filtration and optionally sterilized.

[0032] The Applicant characterized the immortelle extract according to the invention by gas chromatography coupled with mass spectrometry. It was thus demonstrated, as indicated previously, that it contains flavonol heterosides whose B ring is dihydroxylated. These constituents are characteristic of the immortelle extract used according to the invention. In particular, they were not identified in an aqueous immortelle extract (obtained using water at room pressure and temperature as the sole extraction solvent). These flavonol heterosides generally comprise at least one quercetin or quercetagetin heteroside, in particular a quercetin-O-hexoside-O-rhamnoside, rutin, isoquercetin, isoquercitrin or mixtures thereof.Typically, the immortelle extract used according to the invention contains at least 50 pg / ml of flavonol glycosides whose B ring is dihydroxylated.

[0033] The immortelle extract used according to the invention generally further contains chlorogenic acid and leontopodic acid B, in a weight ratio of flavonol heterosides whose ring B is dihydroxylated to chlorogenic acid of between 0.4:1 and 1.2:1, preferably 0.45:1 to 0.9:1 and in a weight ratio of flavonol heterosides whose ring B is dihydroxylated to leontopodic acid B of between 0.3:1 and 1:1, preferably 0.4:1 and 0.8:1. On the other hand, it does not contain chains, in particular linderatin, linderachalcone, methyl-linderatin and gymnochalcone, or mixtures thereof.

[0034] Furthermore, the immortelle extract according to the invention contains at least 20% by weight, preferably at least 25% by weight, of terpenes relative to the total quantity of volatile compounds present in this extract, as measured by gas chromatography coupled with mass spectrometry and by gas chromatography with flame ionization detection.

[0035] Finally, the immortelle extract used according to the invention contains less than 90% by weight, generally less than 80% by weight, more particularly less than 70% by weight, and even less than 60% by weight, of oxygenated terpenes, relative to the total quantity of volatile terpenes present in this extract. These oxygenated terpenes include, in particular, 1,8-cineole, linalool oxides, menthone, neryl oxide, linalool, linalyl acetate, terpinenols, pulegone, alpha-terpineol, neryl acetate, geranial, nerol, geraniol, italidiones, eudesm-5-en-l l -alpha ol, eugenol, sesquiterpenol, gamma-eudesmol, carvacrol, and neric acid. In particular, it has been observed that the extract used according to the invention contains less than 0.1% by weight of italidiones and generally an undetectable amount of italidiones, relative to the total amount of terpenes present in this extract.

[0036] This extract therefore comprises more than 10% by weight, generally more than 20% by weight, more particularly more than 30% by weight and even more than 40% by weight of non-oxygenated terpenes, relative to the total quantity of volatile terpenes present in this extract. It has in particular been observed that these non-oxygenated terpenes comprise more than 20% by weight, and generally at least 30% by weight, of squalene, relative to the total quantity of volatile terpenes present in this extract.

[0037] The immortelle extract advantageously represents from 0.01 to 1% of the total weight of the composition according to the invention. The immortelle extract according to the invention is included in a cosmetic composition which contains a physiologically acceptable medium, in particular cosmetically acceptable, that is to say which does not generate tingling or redness incompatible with cosmetic use. This medium preferably contains an aqueous phase and optionally a fatty phase. It is preferred that the composition is in the form of an emulsion, in particular of the oil-in-water or water-in-oil type, or an aqueous composition.

[0038] The aqueous phase contains water and optionally at least one constituent chosen from polyols and aqueous thickeners. The water advantageously represents from 40 to 80%, for example from 50 to 70%, of the total weight of the composition. The polyol may in particular be chosen from glycerin, propylene glycol, butylene glycol, pentylene glycol and mixtures thereof and it may represent from 5 to 30%, preferably from 15 to 25%, of the total weight of the composition.

[0039] The term "aqueous thickener" means a polymeric compound capable of thus increasing the viscosity of the aqueous phase, in particular an aqueous gelling agent. Such a compound may be chosen from: polysaccharides, such as: cellulose and its derivatives, modified starches, carrageenan, agar agar, xanthan gum and vegetable gums such as guar or locust bean gum; synthetic polymers and in particular homopolymers of sodium acrylate which are optionally crosslinked, as well as acrylic copolymers, in particular copolymers of sodium acrylate and / or of alkyl (meth)acrylate and / or of hydroxyalkyl (meth)acrylate and / or of (polyethoxy)alkyl (meth)acrylate, with optionally at least one other monomer, advantageously 2-acrylamido-2-methylpropane sulfonic acid (AMPS), these copolymers being optionally crosslinked; and their mixtures.

[0040] For its part, when present, the fatty phase may comprise one or more volatile and / or non-volatile oils. Examples of volatile oils are branched alkanes, such as isododecane, and linear C10-C13 alkanes. Non-volatile oils include:

[0041] - esters of acids and mono-alcohols chosen from: mono- and polyesters of linear saturated C2-C10 (preferably C6-C10) acids and linear saturated C10-C18 (preferably C10-C14) mono-alcohols, mono- and polyesters of linear saturated C10-C20 acids and branched or unsaturated C3-C20 (preferably C3-C10) mono-alcohols; mono- and polyesters of branched or unsaturated C5-C20 acids and branched or unsaturated C5-C20 mono-alcohols; mono- and polyesters of branched or unsaturated C5-C20 acids and linear C2-C4 mono-alcohols;

[0042] - C6-C12 fatty acid triglycerides, such as caprylic and capric acid triglycerides and triheptanoin;

[0043] - branched and / or unsaturated C10-C20 fatty acids (such as oleic and linoleic acids);

[0044] - branched and / or unsaturated C10-C20 fatty alcohols (such as octyldodecanol and oleyl alcohol);

[0045] - hydrocarbons such as squalane (C30), in particular plant squalane extracted from olive oil, and hemisqualane (Cl 5);

[0046] - dialkyl carbonates, such as dicaprylyl carbonate and diethylhexyl carbonate;

[0047] - dialkyl ethers such as dicaprylyl ether; and

[0048] - their mixtures.

[0049] We can also cite vegetable oils which contain one or more of the aforementioned constituents.

[0050] Examples of esters of acids and monoalcohols include monoesters such as the mixture of coco caprate and caprylate, ethyl macadamiate, shea butter ethyl ester, isostearyl isostearate, isononyl isononanoate, ethylhexyl isononanoate, hexyl neopentanoate, ethylhexyl neopentanoate, isostearyl neopentanoate, isodecyl neopentanoate, isopropyl myristate, octyldodecyl myristate, isopropyl palmitate, ethylhexyl palmitate, hexyl laurate, isoamyl laurate, cetostearyl nonanoate, propylheptyl capylate and mixtures thereof. Other useful esters are diesters of acids and monoalcohols such as disopropyl adipate, diethylhexyl adipate, diisopropyl sebacate and diisoamyl sebacate.

[0051] Examples of vegetable oils include wheat germ, sunflower, argan, hibiscus, coriander, grape seed, sesame, corn, apricot, castor, shea, avocado, olive, soybean, sweet almond, palm, rapeseed, cottonseed, hazelnut, macadamia, jojoba, alfalfa, poppy, pumpkin, squash, blackcurrant, evening primrose, lavender, borage, millet, barley, quinoa, rye, safflower, candlenut, passionflower, musk rose, Echium, camelina or camellia.

[0052] The fatty phase may further comprise at least one fatty phase structuring agent. By "fatty phase structuring agent" is meant a compound capable of thickening the oils contained in the composition, chosen in particular from waxes, fatty phase gelling agents and pasty fatty substances, as well as mixtures thereof.

[0053] According to a preferred embodiment, this composition also contains at least one depigmenting active ingredient other than the immortelle extract according to the invention, which may in particular be chosen from: plant extracts, in particular a liquorice extract; vitamin C and its derivatives, in particular ascorbic acid, ascorbyl glucoside, ascorbic acid ethyl ether, ascorbyl tetraisopalmitate and magnesium ascorbyl phosphate; arbutin; ferulic acid; kojic acid; resorcinol and its derivatives such as hexylresorcinol and 4-(l-phenylethyl)-l,3-benzenediol marketed in particular under the trade name Symwhite 377® by the company Symrise; salicylic acid, its salts and its esters; extracts of meadowsweet and iris florentina^ dipotassium glycyrrhizinate; tranexamic acid; ellagic acid; nicotinic acid derivatives such as niacinamide;an extract of kiwi (Actinidia chinensis) marketed in particular by Gattefossé; an extract of peony root (Paeonia suffruticosa) marketed in particular by Ichimaru Pharcos under the trade name Botanpi® Liquid; a lipoamino acid of the phenylalanine type modified by undecylenoic acid marketed in particular under the trade name Sepiwhite® by Seppic; an essential oil of Helichrysum italicum; and mixtures thereof.;

[0054] Alternatively or in addition, this cosmetic composition may comprise at least one active ingredient chosen from: anti-free radical agents, moisturizing agents, agents stimulating the differentiation and / or proliferation of keratinocytes and / or fibroblasts; agents stimulating the synthesis of glycosaminoglycans and / or collagen and / or dermo-epidermal anchoring fibrils and / or elastic fibers; agents preventing the degradation of collagen and / or glycosaminoglycans and / or dermo-epidermal anchoring fibrils and / or elastic fibers; anti-glycation agents; and mixtures thereof.

[0055] Examples of such anti-aging active ingredients include: ascorbic acid, its salts, ethers and esters, including ascorbyl glucoside; adenosine; ribose; honey extracts; proteins and glycoproteins, extracted in particular from sweet almond; hydrolyzed vegetable proteins, including those from rice, hibiscus seeds or lupin;polypeptides and pseudodipeptides, such as carcinine hydrochloride, palmitoyl pentapeptide-4 (Pal-Lys-Thr-Thr-Lys-Ser) and palmitoyl tripeptide-38 marketed in particular by SEDERMA under the trade names Matrixyl® 3000 and Matrixyl® Synthe'6, respectively, palmitoyl tripeptide-8 marketed by the company LUCAS MEYER under the trade name Nutrazen®, pentapeptide-18 marketed by the company LIPOTEC under the trade name Leuphasyl® Solution, sh-decapeptide-9 marketed by the company SANDREAM under the trade name Neoendorphin® and palmitoyl hexapeptide-52 marketed by the company INFINITEC under the trade name X50 Myocept® Powder; silanes such as methylsilanol mannuronate; arabinoxylans, extracted in particular from rye flour and galactoarabinans, derived in particular from larch; hyaluronic acid and its salts; polyphenols, extracted in particular from mimosa;alpha-hydroxy acids, including those extracted from lemon and those extracted from hibiscus marketed under the trade name Hibiscus acids ® by Naturex; extracts (generally aqueous) of plants such as water clover, wild pansy, field horsetail, Mafane (Acmella oleracea), donkey thistle (Onopordum acanthium). yarrow (Achillea millefolium, contained in particular in the product Neurobiox® from BASF), embelia (Embelia concinna, as marketed by SEPPIC), prickly pear (Opuntia ficus indica, marketed in particular by MIBELLE AG BIOCHEMISTRY under the trade name AquaCacteen®), sage (Salvia officinalis, sold in particular by PROVITAL GROUP), EU ex negundo (marketed in particular by LABORATOIRES EXPANSCIENCE under the trade name Neurovity®), chestnut, papaya, argan, oats, sunflower, daisy, peony or dill;aqueous extracts of algae, in particular coralline algae, red jania, Ungaria pinna tifada, A. aria esculenta or Nannochlorosis oculata; essential oils, in particular myrtle; zinc and / or copper gluconates; and mixtures thereof.

[0056] The composition according to the invention may further contain different constituents which may be dispersed in the fatty phase and / or in the aqueous phase, provided that these are compatible with topical application to the skin.

[0057] It may thus contain at least one oil-in-water or water-in-oil emulsifier, generally non-ionic, such as polyoxyethylene esters, optionally polyethoxylated sorbitan esters, optionally polyethoxylated fatty acid and glycerol esters, fatty alcohol and sugar ethers such as alkyl glucosides, fatty acid and sugar esters, in particular sucrose esters, and mixtures thereof. The emulsifiers may represent from 2 to 10% and preferably from 4 to 6% of the total weight of the composition.

[0058] The composition according to the invention may also comprise one or more powdery fillers, which are advantageously in the form of porous or hollow microparticles, preferably porous. These microparticles are in principle substantially spherical. These fillers may in particular be chosen from:

[0059] - organic fillers such as: polysaccharide powders and in particular native starch, modified starch or cellulose; acrylic polymer powders such as poly(methyl methacrylate), polyamides or polyolefins; dried algae powders such as Corallina officinalis;

[0060] - inorganic fillers such as silica, clays, perlite and talc;

[0061] - and their mixtures.

[0062] As an inorganic filler, silica is preferred.

[0063] These fillers may represent from 1 to 5% by weight, relative to the total weight of the composition. The composition according to the invention may also comprise additives chosen in particular from organic and / or inorganic photoprotective agents, active in blue light and / or UVA and / or UVB; film-forming polymers based on polysaccharides, capable of forming an anti-pollution protective film, such as the products marketed by SOLABIA under the trade names Pollustop® and Solashield®; perfumes; antioxidant agents; sequestering agents; pH adjusters; preservatives; pigments; dyes; and mixtures thereof.

[0064] This composition may be in any form suitable for topical application to the skin, including milk, cream, fluid, lotion, gel, paste, or film. It is generally a leave-on composition and in particular a skin care composition.

[0065] Alternatively, the composition according to the invention may be a rinse-off composition used for skin care, in particular for the face and possibly the body. In this case, it may, for example, be used as a mask or as an exfoliating paste.

[0066] The composition according to the invention can be applied to the skin of people with uneven skin color due to environmental factors, including pigment spots, chloasma and / or pigmentation defects due to scars or acne marks. It is generally applied to at least one area of ​​the body concerned and more particularly to the skin of the face, décolleté, neck, arms, hands and / or legs, with a view to lightening these areas and / or evening out the skin color. This composition can be applied once or several times a day, for example morning and / or evening.

[0067] In any case, the immortelle extract used according to the invention is applied to the skin in a quantity sufficient to inhibit melanogenesis. For example, a quantity of 0.5 to 5 mg / cm can be applied daily to the affected area of ​​skin. 2, of cosmetic composition containing from 0.01 to 1% by weight of immortelle extract according to the invention. FIGURES

[0068] Figure 1 illustrates the effect of the extract according to the invention on the inhibition of melanin production by mouse B16 melanocytes, compared with two positive controls.

[0069] EXAMPLES

[0070] The invention will be better understood in light of the following examples, which are given purely for illustrative purposes and are not intended to limit the scope of the invention, defined by the appended claims.

[0071] Preparation and characterization of the extract Comparison with an aqueous extract

[0072] 1.1 - Preparation of extracts

[0073] An extract according to the invention was prepared following the method described below.

[0074] The dried flowering aerial parts of Helichrysum italicum were ground using a knife mill equipped with a 12 mm mesh screen. The extraction solvent was separately prepared by mixing fructose, glycerin and water in a mass ratio of 50:25:25 for 1 to 2 hours at 70°C, resulting in a clear and colorless liquid. The solvent was introduced into a reactor to which the ground plant was added in a mass ratio of 5:95 ground dry plant to solvent. Extraction was carried out for 3 hours at 70°C with continuous stirring. Liquid / solid separation was then carried out using a centrifugal spinner, and the crude extract was clarified by frontal filtration on different grades of depth filter plates. The clarified extract was then filtered through a cartridge containing a membrane with a cut-off threshold of 0.22 µm. This gave an extract in the form of an amber liquid.

[0075] 1.2 - Characterization of polyphenols

[0076] The polyphenol composition of the extract prepared in 1.1 was compared with that of an aqueous extract of Helichrysum italicum obtained by maceration in water at 50°C of the flowering tops of immortelle of the species Helichrysum italicum, in a plant / water ratio of 10% by weight. Material

[0077] - Ultra high performance liquid chromatography (Agitent Technologies, USA)

[0078] - 1290 series automatic injector

[0079] - Diode Array Detector (DAD) 1260 series - Mass Spectrometer: Esquire 6000 (Bruker Daltonics, Bremen) equipped with an Electrospray Ionization (ESI) source.

[0080] Sample preparation

[0081] The aqueous extract was diluted 10 eme in a MeOHÆLO mixture (50 / 50). - The extract according to the invention was diluted to 5 eme in a MeOHÆLO mix

[0082] (50 / 50).

[0083] Analysis method

[0084] The solutions obtained after dilution / extraction were filtered through a PTFE filter (0.45 µm) and then injected (IpL) onto an Agitent C18 column (2.1 mm x 100 mm; 1.8 µm) at a temperature maintained at 25°C and at a flow rate of 0.4 mL / min. The following solvents were used: A = H2O / HCOOH (0.1%) and B = ACN / HCOOH (0.1%). The elution gradient of the polyphenols was as follows:

[0085] At the output of the diode array detector, the eluent was injected into the mass spectrometer. Analyses were performed in negative or positive mode.

[0086] LC-MS spectra were acquired over the entire mass range (m / z) from 100 to 1400. All data were then collected and processed by Hystar version 3.0 software.

[0087] Results nd: not detected; <LQ : détecté mais inférieur à la limite de quantification

[0088] As can be seen from this table, the extract according to the invention is characterized by a high content of flavonoid heterosides, in particular O-hexosides of flavonols dihydroxylated on the B ring. They are also richer in chlorogenic acid and dicaffeoyl quinic acid than the aqueous extracts. It was further confirmed by liquid chromatography and mass spectrometry that the "flavonoid O-hexoside" did not correspond to any other of the compounds mentioned above.

[0089] 1.3 - Characterization of chalcones

[0090] The presence of four chalcones (linderatin, linderachalcone, methyl-linderatin, gymnochalcone) in the immortelle extract described above was evaluated using a 2D NMR method with HSQC 'H / 13 C.

[0091] Materials and methods: An aliquot of the immortelle extract according to the invention (100.7g) was evaporated under vacuum at 50°C for approximately 1h in order to remove a maximum of water. A final mass of 74.6g was obtained, corresponding to a loss of 26% in water (m / m).

[0092] An aliquot of this preparation (15 mg) was dissolved in 700 pL of DMSO-d6 in order to be analyzed by 2D NMR at 298 Kelvin.

[0093] 2D NMR analysis was performed using a Bruker Avance AVIII-600 spectrometer equipped with the Cryoprobe® NMR probe. The NMR values ​​were compared with those calculated using ACD Labs software.

[0094] Results: No chalcones were detected in the sample.

[0095] 1.4 - Characterization of volatiles

[0096] The volatile compound composition of the extract prepared in 1.1 was compared with that of the subcritical water extract of immortelle flowering tops, as described in Example 1 of WO2019 / 086602.

[0097] Materials and methods:

[0098] Sample preparation: The lower aqueous phase of the extract according to the invention or of the extract obtained as described in WO2019 / 086602 was separated by decantation to obtain a hydrosol, to which the same mass of hexane was added. The whole was brought to a boil under hexane reflux for 2 hours. The hexane phase was separated and concentrated by distillation and a 0.772g sample of this phase was injected into the gas chromatograph described below.

[0099] Analyses:

[0100] Identification and quantification of compounds are performed by gas chromatography coupled with mass spectrometry (GC-MS), using a VF WAX column (polar) and gas chromatography with flame ionization detection (GC-FID) using the same column, with the following temperature program: 10 min at 60°C, 2°C / min up to 250°C then 15 min at 250°C. Helium (is used as carrier gas. The analyzed extract is injected at a rate of IpL.

[0101] Compounds are identified by a combined search of retention times and mass spectra (internal library coupled with a commercial library). The percentages of each compound are calculated from the peak areas given by the GC-FID without using a correction factor. The peak identification limit is set at 0.15% and their integration limit at 0.01%.

[0102] More than 150 compounds were thus quantified.

[0103] Results:

[0104] The results of this analysis are collected in Table 3 below.

[0105] (1) Percentage reported to the sum of terpenes

[0106] As can be seen from this Table, the extract according to the invention contains less than 60% by weight of oxygenated terpenes, relative to the total quantity of volatile terpenes present in this extract, while the extract according to Example 1 of patent application WO2019 / 086602 contains more than 90% by weight.

[0107] Example 2: Effect of the immortelle extract according to the invention on melanogenesis

[0108] The immortelle extract and aqueous extract described in Example 1 were tested to evaluate their ability to inhibit melanin production.

[0109] 2, 1 - Materials & Method

[0110] Melanocytes (mouse B16 line) were seeded in 96-well plates at a rate of 2000 cells per well in DMEM medium without phenol red containing 10% fetal calf serum, 2mM glutamine, 1mM sodium pyruvate and 100 pg / ml Normocine. The next day, the cells were treated by adding 0.1 pM NDP-MSH to induce pigmentation. Under the test conditions, in the presence of NDP-MSH, 3mM kojic acid and 0.5% vitamin C (ascorbyl glucoside) were used as positive controls for pigmentation inhibition. All conditions were tested in triplicate. The cells were incubated at 37°C 5% CO2 for 72 hours in the presence of extracts and positive controls. Then cell viability is assessed by the XTT method and only non-cytotoxic conditions (whose viability is greater than 85% of that of the untreated control) are analyzed for the amount of melanin.

[0111] For melanin assay, the medium from each well is aspirated and the cells are lysed by adding 50 μl of 1M NaOH to the cell lawn. The plates are shaken for 30 minutes at room temperature and then the lysate is transferred into glass vials and incubated overnight at 95°C. After incubation, the lysates are centrifuged at 2000 rpm to remove cell debris. The absorbance of the supernatant is read at 405 nm and reflects the amount of melanin in each well and the average of the 3 replicates is taken for each condition. A well of cells not treated with NDP-MSH is used as a control and its OD value is subtracted from all OD values ​​of the other wells. Then the percentage of melanin inhibition is calculated according to the formula:

[0112] 100- [(quantity of melanin of the test condition / quantity of melanin of the untreated control) xlOO],

[0113] The significance of the results is assessed using the one-way ANOVA test (for the immortelle extract according to the invention and the aqueous immortelle extract) or the Student test (for kojic acid and vitamin C).

[0114] 2.2 - Results

[0115] As illustrated in Figure 1, the test is validated by highlighting the effectiveness of kojic acid and vitamin C (****p<0.0001).

[0116] Furthermore, Figure 1 shows that the immortelle extract according to the invention significantly inhibits melanocyte pigmentation (*p<0.05). Its effectiveness is comparable to that of vitamin C, which is the whitening active ingredient conventionally used in cosmetics.

[0117] This example thus demonstrates that the immortelle extract according to the invention constitutes a cosmetic active ingredient of choice for lightening the skin.

[0118] By comparison, the effect on pigmentation of the aqueous extract of immortelle was not significantly different from the control, at the different concentrations tested (from 0.01 to 1%). : Cosmetic compositions

[0119] The following compositions are prepared in a conventional manner for those skilled in the art, by mixing the ingredients below in the weight proportions indicated.

[0120] Hand Cream

[0121] Oils

[0122] Polyols 20%

[0123] Shea butter

[0124] Non-ionic surfactants 3-5%

[0125] Co-emulsifier 1-5-2%

[0126] Powdered fillers 2-5%

[0127] Aqueous gelling agents 1-2%

[0128] Hexylresorcinol 0.5%

[0129] Extract according to the invention 0.1%

[0130] Immortelle essential oil 0.001%

[0131] Adenosine 0.04%

[0132] Antioxidant qs

[0133] Perfume qs

[0134] Water qsp 100%

[0135] VI Lightening Lotion

[0136] Aqueous gelling agents 0.5%

[0137] Humectants 3%

[0138] Anti-free radical active ingredients 2%

[0139] Extract according to the invention 0.1%

[0140] Anti-aging active ingredients 1%

[0141] pH adjuster qs

[0142] Perfume qs

[0143] Water qsp 100%

Claims

Claims 1. Cosmetic use of an extract of immortelle of the species Helichrysum italicum, containing flavonol heterosides whose B ring is dihydroxylated, applied topically to the skin, as a skin whitening agent and / or lightening the complexion and / or for homogenizing the color of the skin and / or reducing or preventing the appearance of pigment spots, characterized in that the immortelle extract contains at least 20% by weight of terpenes, relative to the total quantity of volatile compounds present in said extract, including less than 90% by weight of oxygenated terpenes, relative to the total quantity of volatile terpenes present in said extract.

2. Use according to claim 1, characterized in that the immortelle extract contains less than 80% by weight, preferably less than 70% by weight, more preferably less than 60% by weight, of oxygenated terpenes, relative to the total quantity of volatile terpenes present in said extract.

3. Use according to claim 1 or 2, characterized in that the immortelle extract contains at least 25% by weight of terpenes, relative to the total quantity of volatile compounds present in said extract.

4. Use according to any one of claims 1 to 3, characterized in that the immortelle extract contains at least 50 pg / ml of flavonol glycosides of which the B ring is dihydroxylated.

5. Use according to any one of claims 1 to 4, characterized in that the immortelle extract contains chlorogenic acid and leontopodic acid B, in a weight ratio of flavonol heterosides whose ring B is dihydroxylated to chlorogenic acid of between 0.45: 1 and 0.9: 1 and in a weight ratio of flavonol heterosides whose ring B is dihydroxylated to leontopodic acid B of between 0.4: 1 and 0.8:

1.

6. Use according to any one of claims 1 to 5, characterized in that the immortelle extract is capable of being obtained by extraction of the aerial parts of Helichrysum italicum using a mixture of deep eutectic solvents.

7. Use according to any one of claims 1 to 6, characterized in that the immortelle extract is applied to the skin of the face, décolleté, neck, arms, hands and / or legs.

8. Use according to any one of claims 1 to 7, characterized in that the immortelle extract is applied to the skin in a quantity sufficient to inhibit melanogenesis.

9. Use according to any one of claims 1 to 8, characterized in that the immortelle extract is applied to the skin of people with uneven skin color due to environmental factors, in particular pigment spots, chloasma and / or pigmentation defects due to scars or acne marks.

10. Cosmetic process for whitening the skin and / or lightening the complexion and / or for homogenizing the color of the skin and / or reducing or preventing the appearance of pigment spots, comprising the topical application to the skin of an extract of immortelle of the species Helichrysum italicum as defined in one of claims 1 to 6.

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