WO2025191172A1 - Extracts of iris spp. in hair care - Google Patents

Abstract

The present invention relates to an extract of iris spp. rhizomes and compositions containing said extract of iris spp. rhizome for use in the field of cosmetics to limit hair loss and/or promote hair growth.

Description

DESCRIPTION

TITLE: Extracts of Iris spp. in maidenhair

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the use of an extract of rhizomes of at least one species belonging to the genus Iris and the use of compositions containing one of these extracts A' Iris spp. for application in the field of cosmetics, in particular in the hair field, to limit hair and/or body hair loss and/or to promote hair and/or body hair growth.

STATE OF THE ART

Hair care, not only for cosmetic purposes but also to prevent hair loss and to regenerate it, has always required the spirit of research. Many theories have attempted to clarify the etiology of hair loss in cases of baldness, alopecia, alopecia areata, etc., attributing them to seborrhea, increased tension of the tissue on the cranial sphere, reduced blood flow, or certain endocrine or nervous disorders.

The hair follicle is a mini-organ anchored in the skin up to the hypodermis, whose main function is the production of a hair shaft. Their distribution is established during in utero growth and their number is genetically determined. The hair follicle is a dynamic structure that produces hair during the cycle of growth and tissue remodeling. This cycle is divided into three phases:

A growth phase (anagen): the cells of the dermal papilla (fibroblasts) send a signal to the follicle stem cells that allows their proliferation. Cells will transform and envelop the dermal papilla to form the hair matrix. They divide and differentiate into follicular keratinocytes, cells responsible for the structure of the hair. For the hair to be well structured, these keratinocytes need sulfur proteins, vitamin B6 and various minerals such as zinc and magnesium. The duration of this phase determines the length of the hair and depends on the proliferation and differentiation of the matrix cells at the base of the follicle.

A regression phase (catagen): the matrix dies and as a result the dermal papilla is no longer in contact with this matrix. There is no longer any exchange between the cells. The follicle and the dermal papilla move back towards the epidermis. A resting phase (telogen): the cells of the dermal papilla and follicle are intact and inactive. The hair falls out. For a new hair to grow, the cycle must be restarted.

To date, various products have been proposed to combat hair loss, in particular to induce or stimulate hair growth. Most of them combine several active ingredients likely to provide a beneficial effect on the biological parameters involved in hair loss. Among the most commonly encountered active ingredients, we can cite as examples: vitamins such as vitamins A, E, B5, B6, C, H and PP; trace elements such as zinc, copper, magnesium, silicon; protein derivatives such as peptides, sulfur amino acids (methionine, cystine, cysteine or derivatives); essential oils or plant extracts of lipophilic or hydrophilic nature, the list of which is not exhaustive, etc.

So, despite the many options currently available, consumers still need new products to promote hair regrowth that are natural and environmentally friendly.

Plants of the genus Iris Toum. ex L. (abbreviated Iris hereafter) belong to the Iridaceae family. The genus Iris has more than 300 species, widely distributed throughout the world, mainly in the northern hemisphere, in very diverse biotopes (Iris Toum. ex L. | Plants of the World Online | Kew Science accessible at https://powo.science.kew.Org/taxon/urn:lsid:ipni.org:names:326330-2). Species of the genus Iris are perennial herbaceous plants, with rhizomes or bulbs, with alternate leaves of variable shapes. The flowers are distichous, linear or ensiform, borne on a simple or branched stem. The flowers have 3 external segments acting as sepals, generally reflexed, and 3 internal segments (petals), erect, smaller. (Pr. Pierre Delaveau, 2003, p. 305). There are several common Iris species. such as Iris florentina L., Iris pallida Lam., Iris x germanica L., etc.

Iris florentina L., the Florentine iris, is a species native to the Arabian Peninsula, now naturalized in several countries of the Mediterranean basin and prized for its ornamental and olfactory properties.

Iris pallida Lam. is a species native to Italy or the Balkans, now naturalized in several countries of the Mediterranean basin and North America. Growing to over 1 meter in height, the plant has a thick rhizome and broad, sword-shaped leaves, shorter than the stem. The flowers are 2 or 3 per spathe. Large, fragrant, and pale blue in color, they are carried on a short peduncle.

Iris x germanica L., sometimes called "German iris", is a hybrid probably resulting from a cross between Iris pallida Lam. and Iris variegata L., native to the Mediterranean region and now naturalized in many countries around the world. The pointed, sword-shaped leaves measure up to 50 cm in length and 3-4 cm in width. Prized for its ornamental qualities, there are said to be several thousand cultivars.

The rhizomes of Iris x germanica L., Iris florentina L. and Iris pallida Lam. are also valued in perfumery, particularly because of their violet-like scent.

Extracts of species belonging to the genus Iris are also found in several anti-aging cosmetic products, as well as in oral care products.

The main secondary metabolites of Iris species belong to the flavonoid family. They are mainly isoflavones (irigenin, irilone, irilins, irisflorentin, tectorigenin, irisolidones, etc.), flavanones, dihydroflavonols, and flavonols (often in the minority). They are present in aglycone or glycosylated form. Anthocyanins (delphinidin and derivatives) are also found in the flowers, as well as flavones (O-glycosylated and C-glycosylated), mainly in the leaves and flowers (Iwashina and Mizumo 2020; Wang et al. 2010).

Some xanthones are also reported in species of the genus Iris, such as mangiferin or isomangiferin in Iris pallida Lam. or Iris versicolor L..

The presence of triterpenoids is also documented in some species of the genus Iris. Irones (gamma-irone, alpha-irone, alpha-ionone, etc.), present in the absolutes of some species (Iris x germanica L.; Iris florentina L.; Iris pallida Lam.), are formed during rhizome aging by oxidation of bicyclic triterpenes, namely iridals (iripallidal, iriflorentinal, irigermanal, free or esterified by fatty acids) (Jean Bruneton 2015; Wang et al. 2010).

Parts of some species of the genus Iris (seeds Iris pallasii Fisch, ex Trevir., Iris bungei Maxim.) also contain quinones as minor products (hydroxyirisquinones) (Hadfield et al. 2020; Rahman et al. 2000).

Numerous pharmacological studies have been described in the literature for extracts of different species of the genus Iris, for the demonstration of neuroprotective, antioxidant, or anthelmintic activities.

Patent application KR2006-0045694 also discloses an iris extract containing isopallasson C for the treatment of alopecia via the target 5a-reductase. The extract is obtained by methanol extraction followed by counter-extraction with hexane, so as to obtain a fraction soluble in chloroform. The species is not specified, and the extract described in the examples is derived from seeds. The carrier of the activity of such an extract, obtained after purification, is isopallasson C which would inhibit the action of the enzyme 5a-reductase. The extract is administered orally or parenterally, so that the dose of isopallasson C is between 0.001 mg/kg and 10 mg/kg. Isopallasson C (3-((Z)-heptadec-9-enyl)-2-hydroxy-5-methoxycyclohexa-2,5-diene-1,4-dione), with the chemical formula C24H38O4, is a 1,4-benzoquinone with a (Z)-heptadec-9-enyl chain in position 3, a methoxyl group in position 5 and a hydroxyl group in position 2. To our knowledge, the structure of this molecule is not documented in any other document available in the bibliography or in any database of natural molecules, such as the Dictionary of Natural Products, Wikidata, COCONUT (COCONUT: Natural Products Online) or LOTUS (LOTUS: Natural Products Online) in any plant species.

However, to date no bibliographic data mentions an extract of rhizomes

Iris spp. may have activity in limiting hair loss and/or promoting hair growth.

SUMMARY OF THE INVENTION

The first subject of the present invention is a cosmetic use of an extract of Iris spp. rhizomes to limit hair loss and/or body hair and/or to promote hair growth and/or body hair.

The present invention also relates to a use of an extract of Iris spp. rhizomes for preparing a cosmetic composition for limiting hair loss and/or body hair and/or for promoting hair growth and/or body hair.

The present invention also relates to an extract of lris spp. rhizomes for use in limiting hair and/or body hair loss and/or in promoting hair and/or body hair growth.

The second subject of the present invention is a use of a cosmetic composition comprising at least one extract of Iris spp. rhizomes and at least one cosmetically acceptable excipient for limiting hair loss and/or body hair and/or for promoting hair growth and/or body hair.

The present invention also relates to a cosmetic composition comprising at least one extract of rhizomes <PIris spp. and at least one cosmetically acceptable excipient for its use to limit hair loss and/or body hair and/or to promote hair growth and/or body hair.

The third subject of the present invention is a method for the cosmetic treatment of hair and/or body hair, in particular for limiting hair and/or body hair loss and/or for promoting hair and/or body hair growth, comprising the application, preferably topical, of at least one extract of Iris spp. rhizomes or of at least one cosmetic composition comprising at least one extract of Iris spp. rhizomes and at least one cosmetically acceptable excipient, in particular on the hair and/or the scalp.

The present invention also relates to the use of an extract of Iris spp. rhizomes or a cosmetic composition comprising at least one extract of Iris spp. rhizomes and at least one cosmetically acceptable excipient for blocking the olfactory receptor OR8D1 and/or inhibiting the JAK-STAT signaling pathway and/or activating the Wnt/p-catenin pathway.

The present invention also relates to a method for blocking the olfactory receptor OR8D1 and/or inhibiting the JAK-STAT signaling pathway and/or activating the Wnt/p-catenin pathway comprising administering to a person in need thereof an extract of Iris spp. rhizomes or a cosmetic composition comprising at least one extract of Iris spp. rhizomes and at least one cosmetically acceptable excipient.

Other aspects of the invention are as described below.

DETAILED DESCRIPTION OF THE INVENTION

Surprisingly, the inventors discovered that an extract of rhizomes of at least one species of the genus Iris is capable of limiting hair loss and/or promoting hair growth. Indeed, this extract has interesting activities on the olfactory receptor OR8D1 which is involved in the regulation of hair growth. In addition, this extract also has activities of inhibition of the JAK/STAT pathway and activation of the Wnt/p-catenin pathway useful for limiting hair loss and for promoting hair growth.

Definitions

In the present invention, the genus Iris Tourn. ex L. may be abbreviated to //7.s and the different species of the genus Iris Tourn. ex L. may be abbreviated to Iris spp. They include in particular Iris x germanica L., Iris florentina L. and Iris pallida Lam. In the present invention, the plant Iris x germanica L. may be abbreviated to Iris germanica, the plant Iris florentina L. may be abbreviated to Iris florentina, the plant Iris pallida Lam. may be abbreviated to Iris pallida.

By "rhizomes" we mean the underground parts of a plant of the genus Iris.

By "extract of rhizomes of Iris spp." is meant, in the present invention, the product of extraction of the rhizomes as defined above of at least one plant of a species belonging to the genus Iris. Preferably, it is an extract obtained from rhizomes of Iris germanica, Iris florentina, or Iris pallida.

For the purposes of the present invention, the term “extraction product” means the product obtained after extraction of all or part of the plant, with a solvent, called extraction solvent, i.e. a product present in the extraction solvent which may then optionally be in a concentrated or dry form after partial or total evaporation of the extraction solvent. It may be a dry extract.

For the purposes of the present invention, the term "dry extract" means an extract free of extraction solvent or carrier, or containing only insignificant traces thereof. Such a dry extract thus contains only material resulting from the extraction of Iris spp.

For the purposes of the present invention, the term “support” means a substance capable of solubilizing or dispersing (e.g. by adsorption) within itself the extract according to the invention in a homogeneous manner.

By "approximately" is meant in the present invention that the value concerned may be lower or higher by 10%, in particular by 5%, in particular by 2%, more particularly by 1%, compared to the indicated value.

For the purposes of the present invention, the term “polar solvent” means a solvent chosen from the group consisting in particular of water, subcritical water, glycerin, and mixtures thereof.

For the purposes of the present invention, the term "moderately polar solvent" means a solvent chosen from the group consisting in particular of C1 to C5 alcohols, C3 to C5 glycols (such as propylene glycol, butylene glycol, butanediol, or pentylene glycol), acetone, C1 to C6 alkyl esters (such as C1 to C6 alkyl acetates and in particular ethyl acetate, or isopropyl acetate), triethyl citrate, mixtures of these with water (a hydro-alcoholic mixture, more particularly a C1 to C5 alcohol/water mixture, or an acetone/water mixture for example), hydrotropic solutions, and mixtures of these. For the purposes of the present invention, the term "apolar solvent" means a solvent chosen, for example, from heptane, hexane, limonene, ethyl oleate, halogenated hydrocarbons (for example, chlorinated hydrocarbons C1 to C3 such as chloroform or dichloromethane), supercritical CO2, a mixture of supercritical CO2 and ethanol (preferably in a supercritical CO2 / ethanol ratio of at least 70/30 (w/w)), bio-sourced solvents such as EcoXtract® LIPOCOS (Supplier Pennakem Europe) and mixtures thereof.

A "hydrotropic solution" means a mixture of water and a hydrotrope.

By "hydrotrope" we mean a water-soluble amphiphilic molecule which, from a certain concentration, can extract hydrophobic compounds and in particular moderately polar compounds by allowing their solubilization in water.

By "hydroalcoholic mixture" is meant a mixture of water and one or more water-miscible alcohols, in particular a C1 to C5 alcohol such as, for example, ethanol. The proportion of alcohol(s) (e.g., C1 to C5 alcohol such as ethanol) / water will advantageously be 9.5:0.5 to 1:9 (v/v), in particular 9.5:0.5 to 1:1 (v/v), preferably 9:1 to 6:4 (v/v), for example 8:2 to 6:4 (v/v), in particular approximately 7:3 (v/v).

For the purposes of the present invention, “supercritical CO2 extraction” means extraction using CO2 in a supercritical state, i.e. subjected to a pressure and temperature higher than its critical point. The temperature must therefore be higher than 31°C and the pressure higher than 74 bars. In its supercritical phase, CO2 is a completely neutral, non-toxic, non-polluting, non-flammable solvent allowing the extraction of lipophilic compounds. Supercritical CO2 can have its polarity modified by the addition of a polar co-solvent such as ethanol in order to broaden the range of polarity of the extracted molecules. Supercritical CO2 extraction thus constitutes a preferred alternative to petrochemical solvents such as hexane or heptane.

For the purposes of the present invention, the term "isopallasson C" means the molecule 3-((Z)-heptadec-9-enyl)-2-hydroxy-5-methoxycyclohexa-2,5-diene-1,4-dione), which has the empirical formula C24H38O4 and a molar mass of 390.56 g/mol, as described in patent application KR2006-0045694 and having the following structure: For the purposes of the present invention, the term "isomer" of isopallasson C means a molecule with the empirical formula C24H38O4, i.e. identical to that of isopallasson C. It is therefore a constitutional isomer.

By extract “free” of a molecule, we mean that said molecule is absent from the extract as described in the invention or that its possible presence is not detectable because it is lower than the detection limit of the usual suitable detectors (diode array detector (DAD) or charged aerosol detector CAD) and/or the high resolution mass spectrometer (HRMS)). By “hair and body hair”, we mean hair, body hair, eyebrows, eyelashes and/or fur, preferably hair.

By "phanère" we mean hair, body hair, eyebrows, and/or eyelashes, preferably hair.

Hair loss means the total or partial, preferably partial, loss of hair, for example due to reduced hair growth and/or accelerated hair loss. The consequences of hair loss are a temporary or permanent, partial or total absence of hair.

By the term "limit" we mean to stop, slow down, reduce, attenuate, diminish and/or halt.

The term "limiting hair and/or body hair loss" means stopping hair and/or body hair loss, reducing hair and/or body hair loss and/or alleviating hair and/or body hair loss, in particular in a mammal, preferably a human being.

By the term "promote" is meant to increase, augment, favor, amplify and/or accelerate.

The term "promoting the growth of hair loss and/or body hair" means increasing hair growth and/or body hair, accelerating hair growth and/or body hair, promoting hair regrowth and/or body hair, increasing hair follicle density, achieving fuller hair coverage, and/or promoting follicular regeneration. This also includes regulating the phases of the hair follicle cycle.

In the present invention, the term "cosmetically acceptable" is intended to mean that which is useful in the preparation of a cosmetic composition, which is generally safe, non-toxic and neither biologically nor otherwise undesirable and which is acceptable for cosmetic use, in particular by topical application, in particular to the hair and/or the scalp. By "cosmetic use" is meant a non-therapeutic use of an extract of iris spp. rhizomes according to the invention for its cosmetic effects, alone or in a composition, in particular to limit hair loss and/or body hair and/or to promote hair growth and/or body hair.

By “topical application” is meant an application to the skin (in particular the scalp), mucous membranes, and/or appendages (in particular hair and/or body hair), preferably to the skin and/or appendages, in particular the hair and/or scalp.

DESCRIPTION OF THE METHODS OF IMPLEMENTATION

Extract dris spp.

The invention relates to the use of an extract of Iris spp. rhizomes for limiting hair loss and/or body hair loss and/or for promoting hair growth and/or body hair growth (in particular capillary growth).

The invention also relates to the use of an extract of iris spp. rhizomes to promote hair regrowth.

The invention also relates to the use of an extract of iris spp. rhizomes to increase the density of hair follicles and/or to obtain more covering hair and/or to promote follicular regeneration.

According to one embodiment, the extract of rhizomes of Iris spp. is obtained from rhizomes of Iris germanica, dllris pallida, dllris jlorentina or a mixture thereof. Thus, the extract according to the invention is advantageously chosen from an extract of rhizomes of Iris germanica, an extract of rhizomes of dllris jlorentina, an extract of rhizomes of Iris pallida and a mixture thereof.

More advantageously, Iris spp. rhizome extract is obtained from Iris germanica rhizomes.

Preferably, the Iris spp. rhizome extract is free of isopallason C and, preferably, is free of isopallason C and its isomers.

In a particular embodiment of the invention, the extract of rhizomes of Iris spp. is obtained from a culture of cells of iris spp., in particular of Iris germanica, of iris pallida, of iris jlorentina or of a mixture thereof, preferably of Iris germanica.

According to a preferred embodiment of the invention, the extract is obtained by supercritical CO2 extraction of rhizomes of Iris spp., in particular of rhizomes of Iris germanica, of Iris pallida, àllris jlorentina or a mixture of these, preferably from allris germanica rhizomes.

According to a particular embodiment, the extract according to the invention can be obtained by a process as described below.

Iris spp. rhizomes can be fresh or dried, whole, cut or ground, and then subjected to an extraction step. Advantageously, the Iris spp. rhizome is dried and ground before being subjected to an extraction step.

In one embodiment of the invention, the dried and ground rhizome may be wetted in water before extraction.

A process for preparing an extract according to the invention comprises an extraction step, and more particularly is obtained by extracting Iris spp. rhizomes with an extraction solvent chosen from polar to apolar solvents and mixtures thereof, i.e. chosen from polar solvents, moderately polar solvents, apolar solvents and mixtures thereof.

The ratio of plant weight to extraction solvent volume can vary, more specifically, from 1/5 to 1/100. Extraction can last from 1 minute to 48 hours, including 1 hour to 24 hours. Extraction can be repeated 2 to 3 times.

In one embodiment, the extraction solvent may be chosen from supercritical CO2 with or without ethanol co-solvent, hexane, heptane, bio-sourced solvents of the EcoXtract® LIPOCOS type, ethyl oleate, ethyl acetate, isopropyl acetate, triethyl citrate, a C3 to C5 glycol, a C1 to C5 alcohol, a hydroalcoholic mixture (in particular a C1 to C5 alcohol/water mixture), glycerin, a hydrotropic solution, water, and a mixture thereof.

Advantageously, it will be supercritical CO2 with or without ethanol co-solvent, hexane, heptane, a bio-sourced solvent such as EcoXtract® LIPOCOS, ethyl oleate, ethyl acetate, isopropyl acetate, triethyl citrate, a C3 to C5 glycol, a C1 to C5 alcohol, or a hydroalcoholic mixture such as a C1 to C5 alcohol/water mixture.

More particularly, the extraction solvent will be chosen from supercritical CO2, a hydroalcoholic mixture (such as a C1 to C5 alcohol/water mixture), ethyl acetate, heptane, and water, preferably supercritical CO2.

More advantageously, it will be supercritical CO2 with or without ethanol co-solvent, or ethyl acetate.

Even more advantageously, it will be supercritical CO2 with or without ethanol co-solvent, i.e. supercritical CO2 possibly mixed with ethanol, CO2 supercritical remaining the majority solvent. The supercritical CO2 / ethanol ratio will preferably be at least 70/30 (w/w). Preferably, the extraction solvent will be supercritical CO2.

In the above embodiments, the supercritical CO2 / ethanol ratio will preferably be at least 70/30 (w/w), especially 70/30 to 99/1 (w/w), when supercritical CO2 is used with an ethanol co-solvent.

According to another particular embodiment, the supercritical CO2 extraction is carried out at a temperature of 32°C to 55°C, at a pressure of between 200 bars and 600 bars. The plant weight/supercritical CO2 volume ratio can vary from 1/5 to 1/100, in particular from 1/10 to 1/100. The extraction can last from 1 minute to 48 hours, in particular from 1 hour to 24 hours. The extraction can be repeated 2 to 3 times.

In another particular embodiment, at the end of the extraction, the extraction continues with supercritical CO2 alone in order to dry the plant.

Preferably, the extract obtained at the end of the extraction is filtered in order to recover a clear liquid phase free of particles. The liquid phase obtained can be more or less concentrated, up to the point of obtaining a dry extract.

In another embodiment, a support may be added during the concentration step so as to obtain an extract containing from 1% to 80% by weight of dry extract, in particular from 20% to 60% of dry extract. The support may be maltodextrin, lactose, silica, acacia or arabic gum, glycerin or a glycerin/water mixture, a glycol, a vegetable oil, triethyl citrate, ethyl oleate, dicaprylyl carbonate, octyl dodecanol, caprylic/capric triglyceride, a water/solubilizer mixture (the solubilizer being a compound capable of solubilizing the extract in water) or water/surfactant, or any other cosmetologically acceptable support, preferably of biosourced origin such as, for example, biosourced glycols, in particular C3 to C5 (1,2-pentanediol; 1,3-butanediol; 1,3-propanediol, etc.), esterified fatty acids and also hydrotropes such as, for example, alkyl glycosides (Sepiclear, Apyclean, APXC4, etc.). Advantageously, the extract according to the invention is placed on a caprylic/capric triglyceride support.

The extract of Iris spp. rhizomes as described above helps to limit hair loss and/or promote hair growth.

In addition, the use of the extract according to the invention makes it possible to promote hair regrowth. The use of the extract according to the invention makes it possible in particular to increase the density of hair follicles and/or to obtain more covering hair and/or to promote follicular regeneration. According to one embodiment of the invention, the extract according to the invention is intended to be applied topically and is therefore in a form suitable for such topical application.

Cosmetic compositions

The present invention also relates to a use of a cosmetic composition comprising at least one extract of Iris s/v rhizomes and at least one cosmetically acceptable excipient for limiting hair loss and/or for promoting hair growth and/or for promoting hair growth (in particular hair growth). The cosmetic composition according to the invention makes it possible to increase the density of hair follicles and/or to obtain more covering hair and/or to promote follicular regeneration.

The cosmetic composition according to the invention also makes it possible to promote the regrowth of hair and/or body hair, in particular hair regrowth.

Advantageously, the extract included in the cosmetic composition is as described above.

Advantageously, the cosmetic composition comprises an extract obtained by supercritical CO2 extraction, i.e. a supercritical CO2 extract of rhizomes of iris spp., in particular Iris germanica, Iris pallida, Iris jlorentina or a mixture thereof, preferably Iris germanica.

The cosmetic composition may comprise from 0.01% to 5%, preferably from 0.01% to 4%, more preferably from 0.01% to 2%, even more preferably from 0.01% to 1% of Iris spp. extract by weight of dry extract relative to the total weight of the composition. This percentage by weight of dry extract is understood to be exclusive of the weight of the possible support, if any, and therefore only concerns the dry plant extract.

The cosmetic composition according to the invention is preferably in a form suitable for topical application, in particular to the scalp and/or hair.

The cosmetic composition according to the invention can thus be presented in the forms which are usually known for topical application, that is to say in particular lotions, shampoos, balms, mousses, gels, dispersions, emulsions, sprays, serums, masks or creams, with excipients allowing in particular penetration in order to improve the properties and accessibility of the active ingredient.

We thus distinguish between formulated products that can be rinsed and formulated products that do not require rinsing. Preferably, the cosmetic composition according to the invention has a light texture which also allows optimal penetration without greasing the hair and/or body hair, or the scalp.

The cosmetic composition according to the invention, administered for example topically, generally contains, in addition to the extract as described above, a physiologically acceptable medium, generally based on water or solvent, for example alcohols, ethers or glycols. It may also contain surfactants, complexing agents, preservatives, stabilizing agents, emulsifiers, thickeners, gelling agents, humectants, emollients, trace elements, essential oils, perfumes, colorants, moisturizing agents and/or thermal waters, etc.

From the first administrations, for example topically or orally, of the composition according to the invention, the hair will regain strength and vitality and regrowth will be encouraged.

The use of the composition as described above may aim in particular to promote hair regrowth.

According to one embodiment of the invention, the cosmetic composition as described above is intended to be applied topically.

Cosmetic process:

The invention also relates to a method for the cosmetic treatment of hair and/or body hair, in particular for limiting hair and/or body hair loss and/or for promoting hair and/or body hair growth, comprising the application, preferably topical, of at least one extract of Iris spp. rhizomes or of at least one cosmetic composition comprising at least one extract of Iris spp. rhizomes and at least one cosmetically acceptable excipient, in particular on the hair and/or the scalp.

This process helps in particular to promote the regrowth of hair and/or body hair, in particular capillary regrowth.

This process also helps to increase the density of hair follicles and/or to obtain more covering hair and/or to promote follicular regeneration.

The extract of Iris spp. rhizomes will more particularly be an extract as defined above and the cosmetic composition will more particularly be a cosmetic composition as defined above.

EXAMPLES The following examples illustrate the invention without limiting its scope. Examples 1 to 6 illustrate different types of extraction for the preparation of rhizome extracts of Iris germanica (examples 1 to 4), 'iris florentina (example 5) and 'iris pallida (example 6). Example 7 demonstrates the absence of isopallason C and its isomers in these extracts and Examples 8 to 10 highlight the effect of these extracts on limiting hair loss and hair growth.

Example 1: Extraction of /r/v germanica by supercritical CO2 followed by support

300 grams of dried and ground rhizomes of Iris germanica are extracted by supercritical CO2 at a pressure of 250 bars and a temperature of 40°C at a flow rate of 10 kg/hour for 180 minutes. After expansion to atmospheric pressure and return to room temperature, the extract is then recovered, filtered and added with a caprylic/capric triglyceride support. The extract obtained contains 45% dry extract of Iris germanica rhizome and 55% caprylic/capric triglyceride.

Example 2: Hydroalcoholic reflux extraction of /r/v germanica

100 grams of dried and ground rhizomes of iris germanica are extracted under reflux with stirring by 1 liter of an ethanol / water mixture 70:30 (v / v) for 1 hour in a reactor. The extract is then filtered on a K900 filtration plate and is dried under vacuum to obtain 24 grams of dry extract.

Example 3: Room temperature extraction with ethyl acetate of Iris germanica 100 grams of dried and ground rhizomes of iris germanica are extracted at room temperature with stirring with 1 liter of ethyl acetate for 14 hours in a reactor. The extract is then filtered on a K900 filtration plate and dried under vacuum to obtain 2.3 grams of dry extract in the form of a fatty paste.

Example 4: Room temperature heptane extraction of Iris germanica

500 grams of dried and ground rhizomes of iris germanica are extracted at room temperature with stirring by 500 milliliters of heptane for 1 hour in a reactor. The extract is then filtered on a K900 filtration plate and is dried under vacuum to obtain 2.5 grams of dry extract in the form of a fatty paste. Example 5: Room temperature aqueous extraction of florentina

1 kilogram of dried and crushed Iris florentina rhizomes are extracted at room temperature with stirring with 10 liters of water for 1 night in a reactor. The extract is then filtered on a K900 filtration plate and dried under vacuum to obtain 260 grams of dry extract.

Example 6: Hydroalcoholic reflux extraction of /r/v pallida

500 grams of dried and ground rhizomes of A' Iris pallida are extracted under reflux with stirring by 5 liters of an ethanol / water mixture 70:30 (v/v) for 1 hour in a reactor. The extract is then filtered on a K900 filtration plate and is dried under vacuum to obtain 130 grams of dry extract.

Example 7: Evaluation of the presence of isopallasson C and its isomers in extracts of /r/v spp.

Sample preparation:

20 mg of the extract to be analyzed are solubilized in 400 pL of a suitable recovery solvent, chosen from water, ethyl acetate, dimethyl sulfoxide (DMSO), or a mixture of DMSO and water or ethyl acetate, so as to obtain a stock solution at 50 mg/ml.

30pL of the stock solution are diluted in 120pL of the appropriate solvent, consisting of water, methanol or ethyl acetate, so as to obtain a perfectly clear solution.

For example:

- 20 mg of extract obtained according to example 1 are solubilized in 400 pL of ethyl acetate and 30 pL of the solution obtained are diluted in 120 pL of ethyl acetate;

- 20 mg of extract obtained according to example 2 are solubilized in 400 pL of DMSO and 30 pL of the solution obtained are diluted in 120 pL of methanol;

- 20 mg of extract obtained according to example 3 are solubilized in 400 pL of DMSO and 30 pL of the solution obtained are diluted in 120 pL of ethyl acetate;

- 20 mg of extract obtained according to example 4 are solubilized in 400 pL of a DMSO / ethyl acetate mixture (1: 1) (v/v) and 30 pL of the solution obtained are diluted in 120 pL of ethyl acetate;

- 20 mg of extract obtained according to example 5 are solubilized in 400 pL of a DMSO / water mixture (1:1) (v/v) and 30 pL of the solution obtained are diluted in 120 pL of water.

Analytical conditions: - Instrument: UHPLC-Acquity / DAD / Synapt G2Si

- Column: Acquity UPLC HSS C18 T3 2.1 mm x 100 mm 1.8pm (Waters)

- Mobile phase:

A: Water + 0.1% formic acid

B: Acetonitrile

- Gradient according to the conditions of Table 1:

[Table 1]

- Oven temperature: 40°C

- Injection volume: 2 pL

- UV acquisition: 200 - 500 nm

- High-resolution mass spectrometry acquisition:

Acquisition mode: centroid

Type of acquisition: DDA (CE: ramp) | Neg

HRMS Resolution: Resolution

Mode of acquisition: continuum

Acquisition type: MSe (CE: ramp) | Neg & Pos

HRMS Resolution: Resolution

The Synapt-G2Si high-resolution mass spectrometry instrument is calibrated with sodium formate solution for m/z measurements in the range 100 - 1200 Thomson (Th) with accuracies below 1 milliDalton (mDa) on all ions of interest. During acquisitions and to keep the instrument calibrated, leucine enkephalin is infused every 20 seconds with the two ions 554.2615 th and 236.1035 th used as reference points.

The instrument has four acquisition modes: either with high m/z measurement resolutions (35k) but lower sensitivity; or with higher m/z measurement resolutions low (15k) but increased sensitivity. In order to be in the best sensitivity conditions for the search for low intensity ions, the acquisitions were carried out in the sensitive mode. The search for signals of interest at the level of the acquisition in negative mode was done on the adducts “-H” and “+HCOOH-H” which are the most commonly observed on this instrument when using formic acid as an additive in the aqueous phase (0.1% v/v here).

For the generation of empirical formulas from observed m/z, the precision of the m/z measurement used is 3 mDa (7.7 ppm for a monoisotopic mass of 390). Anything higher than this value is irrelevant. It is important to consider that this limit is high but used for the purpose of trace research. Regarding the intensity of the m/z peaks, still with a view to trace research, a low limit (1000 absolute units) is used; this value is low compared to the intensities usually observed during annotations.

No trace of isopallasson C or any of its isomers was detected under these conditions in the extracts from Examples 1, 2, 3, 4, 5 and 6.

Example 8: Involvement of the olfactory receptor 0R8D1

Olfactory receptors are expressed primarily in the nasal epithelium. However, their expression is also detected in several other human tissues where they play roles unrelated to olfaction. Ralf Paus's team also shows that the olfactory receptor OR2AT4 is expressed in the epithelium of human hair follicles and is capable of regulating hair growth (Chéret et al., 2018).

In a clinical study, the inventors showed overexpression of the olfactory receptor 0R8D1 in hair follicles in volunteers with proven hair loss compared to volunteers without hair loss.

Sotolon, an agonist of the 0R8D1 receptor, promotes the transition to the catagen phase.

The inventors therefore studied in vitro the effect of two known antagonists of the olfactory receptor 0R8D1 on the hair follicle. These are 2-ethyl fenchol and alpha isomethyl ionone.

These 2 molecules, tested at 3pM, prolong the anagen phase.

The inventors then tested an extract of Iris spp. prepared according to Example 1 to evaluate its effects on the different stages of the hair cycle.

This extract solubilized in ethanol was tested at 10 pg/ml (a solvent control containing 0.1% ethanol was evaluated). The experiments were performed on human hair follicles from surgical procedures. The experiments were performed on follicles from two different donors.

Hair follicles were microdissected and cultured in a 48-well plate with one hair follicle per well. Culture was carried out at 37°C with 5% CO2 in Williams E medium (Gibco Life Technologies) supplemented with L-glutamine (2mM), T hydrocortisone (10ng/ml), insulin (10pg/ml) and a penicillin/streptomycin mixture (1%).

Photographs (50x magnification) are taken regularly every other day for each hair follicle. Photographs at 200x magnification are also taken and analyzed on the first day (Dl) and the last day of the study (Dl 1).

After 3 days of control period, the medium is changed and the iris spp. extract or the vehicle (0.1% ethanol) is added to the medium. From the ^5th day (D5) and until D10, the decision to continue the culture is confirmed if at least 20% of the hair follicles in the vehicle group are in the anagen phase. On D6, the medium is changed again and the iris spp. extract or the vehicle (0.1% ethanol) is added to the medium again.

The results obtained are summarized in Table 2 below.

[Table 2]

The inventors demonstrate that an extract of Iris spp., via the olfactory receptor 0R8D1, is capable of prolonging the anagen phase of the hair cycle, thus promoting hair growth.

Example 9: Evaluation of an extract of /r/v germanica on the JAK-STAT pathway

The aim of this example is to confirm the JAK-STAT signaling pathway inhibition activity of an Iris germanica extract in a cellular model. In this model, interleukin IL-6 is used to activate the JAK1/2-STAT3 pathway by activating IL-6 receptors expressed in this epithelial sheath of hair follicles. IL-6 is a cytokine that acts as an inhibitor of the hair growth cycle, its overexpression in a transgenic mouse model resulting in delayed hair growth. Furthermore, in androgenetic alopecia, IL-6 is reported to be overexpressed in dermal papilla cells under the influence of androgens (Kwack et al. 2012). IL-6 has also been reported to delay hair follicle growth in humans.

The study is carried out on follicular keratinocytes from the outer epithelial sheath of hair follicles (ORS model - Outer Root Sheath). The keratinocytes are cultured in 96-well plates in a suitable medium (CnT-PR from Cellntec). 48 hours later, the cells are washed with alkaline phosphate buffer (PB S) and the medium is replaced with KSFM medium (standard maintenance medium for human primary keratinocytes). After 4 hours, the cells are treated for 1 hour with the test substances (Iris germanica extract according to example 1 at 50 and 100 pg/ml diluted in ethanol) or the reference compound (Tofacitinib at 5 pM diluted in DMSO). Then the IL-6 stimulation treatment (Stim IL6) is carried out at 100 ng/ml for 15 minutes.

All experimental conditions are carried out with n=3 donors and n=3 technical replicates.

The activation level of the JAK/STAT signaling pathway is estimated by evaluating the phosphorylation level of the STAT3 protein using the commercial kit Cisbio 62AT3PEG or Cisbio 64NT3PEG (Perkin Elmer). Statistical analysis is performed by a parametric test after verification of normality and equivalence of variance, otherwise a non-parametric test is chosen.

The results obtained are presented in Table 3 below. [Table 3]

SEM = Standard error of the mean

*: p<0.001 vs DMSO 0.1% + Stim IL6

**: p<0.01 vs Ethanol 0.1% + Stim IL6

***: p<0.001 vs Ethanol 0.2% + Stim IL6

Treatment of keratinocytes with IL-6 induced a significant increase in the phosphorylation level of STAT3, thus inhibiting the JAK/STAT pathway. The reference compound (Tofacitinib tested at 5pM) significantly reduced the phosphorylation level of STAT3 by 97.5%. These expected results validate the test.

The Iris germanica extract obtained according to example 1 significantly and very markedly inhibits the level of STAT3 phosphorylation induced by IL-6 stimulation.

The inventors thus highlight the interest of an extract of Iris germanica in limiting hair loss and in promoting hair growth by lengthening the hair life cycle, by significantly inhibiting the activation of the JAK/STAT pathway induced by TIL6 in the cells of the outer epithelial sheath.

Example 10: Evaluation of several extracts of /r/’v spp. on the activation of the Wnt/p-catenin pathway

Hair follicle development and growth are influenced by compounds expressed by the dermal papilla, proteins such as Wnt and growth factors such as keratinocyte growth factor (KGF) or epithelial growth factor (EGF). Hair is constantly renewed, and of the 100,000 to 150,000 hairs in a head of hair, the majority are in the growth phase. A healthy head of hair loses about 60 to 100 hairs per day, normally and physiologically. Beyond this level, hair loss is considered pathological, whether it is occasional or ongoing.

Wnt is a family of glycoproteins whose name corresponds to the union of Wg (wingless) and Int (integration site). The Wnt protein signaling pathway via beta-catenin is called canonical, that is to say the privileged pathway. The Wnt signal activates hair regeneration and participates in its growth. Wnt binds to extracellular receptors allowing the stabilization of intracellular beta-catenin, thus preventing its degradation by the proteasome. P-catenin can then penetrate the nucleus and play a role as a co-activator of transcription factors and stimulate the expression of specific genes involved in hair growth such as the gene coding for KGF.

Hair development depends on a signaling loop between keratinocytes and dermal papilla cells. Wnt expression in keratinocytes induces an increase in P-catenin in dermal papilla cells, regulating signaling pathways including growth factors that guide hair morphogenesis. KGF is an endogenous paracrine mediator important in hair follicle development, differentiation, and growth. P-catenin and KGF are highly present in the anagen phase and then disappear. Loss of P-catenin expression stops the Wnt signal and induces the transition to the catagen phase.

Experiments were performed on human cells from the dermal papillae of follicles of three donors. The cells were seeded in 96-well plates and cultured for 24 h in HFDPC medium (Promocell) with the necessary supplements. The cells were incubated with the polybrene infection/transfection reagent (Sigma #TR-1003-G) and transduced with a TCF/LEF Luciferase Reporter Lentivirus (Wnt/p-catenin Signaling Pathway) (BPS Bioscience #79787 lot 2201024) expressing the luciferase gene under the control of the Wnt/P-catenin promoter (TCF/LEF Transcriptional Response Element). The cells are then incubated for 24 hours with the products to be tested, i.e. either with an extract of Iris germanica (5, 10, 50 or 100 pg/ml) diluted in DMSO, or with an extract of Iris florentina (5, 10 or 50 pg/ml) diluted in DMSO, or with an extract of Iris pallida (5, 10, 50 or 100 pg/ml) diluted in DMSO. The extracts tested are obtained according to different extraction conditions as follows: - EtOH70 extraction carried out according to the conditions of example 2 or 6 regardless of the species of Iris, - AcEth extraction carried out according to the conditions of example 3 whatever the species d7/'/.s, and

- n-Hep extraction carried out according to the conditions of example 4 whatever the Iris species, - water extraction carried out according to the conditions of example 5 whatever the Iris species.

A positive control (apigenin at 10mM) was also tested as well as a TCF/LEF reporter stimulation control (Wnt3a at 10mM). Activation of the Wnt/p-catenin pathway was highlighted by quantification of luminescence due to luciferase expression.

Wnt/β-catenin activity is assessed and quantified after reading the luminescence linked to the expression of the luciferase reporter gene under the control of the Wnt/β-catenin promoter (TCF/LEF).

The following Table 4 presents the activation of the Wnt/p-catenin pathway after incubation of the Iris germanica extract obtained according to different types of extraction.

[Table 4]

Table 5 below shows the activation of the Wnt/p-catenin pathway after incubation of Iris florentina extract obtained using different types of extraction.

[Table 5]

The following Table 6 presents the activation of the Wnt/p-catenin pathway after incubation of the Iris pallida extract obtained according to different types of extraction.

[Table 6] The inventors demonstrate, regardless of the lris species and the type of extraction performed, that the CIris rhizome extract is active on the Wnt/p-catenin pathway. This reflects the involvement of CIris rhizome extract in hair regrowth.

References:

KR2006-0045694 ;

Jean Bruneton, Pharmacognosy Phytochemistry Medicinal Plants, Ed. Lavoisier, ^5th edition, 2015, p. 727-728;

Chéret et al., Olfactory receptor OR2AT4 regulates human hairgrowth, Nat Commun 2018, 18, 9(1):3624;

Pr. Pierre Delaveau, Explain plants to me, Ed. Pharmathèmes, 2003, p.305;

Hadfield et al., A High-Yielding Synthesis of the Naturally Occurring Antitumor Agent Irisquinone, Molecules 2000, 5, 82-88;

Iwashina and Mizuno, Flavonoids and xanthones from the Genus Iris: phytochemistry, relationships with flower colors and taxonomy, and activities and function, Natural Product Communications 2029, 15(10) 1-35;

Kwack et al., Dihydrotestosterone-Inducible IL-6 Inhibits Elongation of Human Hair Shafts by Suppressing Matrix Cell Proliferation and Promotes Regression of Hair Follicles in Mice, J Invest Dermatology 2012, 132(1) 43-9;

Rahman et al., Two New Quinones from Iris bungei, Chem. Pharm. Bull. 2000, 48(5), 738-739; Wang et al., Flavonoids of the Genus Iris (Iridaceaef Mini-reviews in Medicinal Chemistry 2010, 10(7), 643-661.

Claims

1. Cosmetic use of an extract of Iris spp. rhizomes to limit hair loss and/or to promote hair growth. 2. Use of an extract according to claim 1, for promoting hair regrowth. 3. Use of an extract according to any one of claims 1 to 2, to increase the density of hair follicles and/or to obtain more covering hair and/or to promote follicular regeneration. 4. Use of an extract according to any one of claims 1 to 3, characterized in that said extract is in a form suitable for topical application. 5. Use of an extract according to any one of claims 1 to 4, characterized in that the extract is chosen from an extract of Iris germanica rhizomes, an extract of Iris florenlina rhizomes, an extract of Iris pallida rhizomes and a mixture thereof. 6. Use of an extract according to any one of claims 1 to 5, characterized in that the extract is obtained by extraction of the rhizomes of Allris spp. with an extraction solvent chosen from supercritical CO2, a hydroalcoholic mixture, ethyl acetate, heptane, and water, preferably by supercritical CO2 extraction. 7. Use of a cosmetic composition comprising at least one extract of Allris spp. rhizomes and at least one cosmetically acceptable excipient for limiting hair loss and/or for promoting hair growth. 8. Use of a cosmetic composition according to claim 7, characterized in that the composition comprises 0.01% to 5% of the extract by weight of dry extract relative to the total weight of the composition. 9. Use of a cosmetic composition according to either of claims 7 and 8, characterized in that the extract is obtained by extraction with an extraction solvent chosen from supercritical CO2, a hydroalcoholic mixture, ethyl acetate, heptane, and water, preferably by extraction with supercritical CO2. 10. Use of a cosmetic composition according to any one of claims 7 to 9, characterized in that the composition is in a form suitable for topical application. 11. Use of a cosmetic composition according to any one of claims 7 to 10, to promote hair regrowth. 12. Use of a cosmetic composition according to any one of claims 7 to 11, to increase the density of hair follicles and/or obtain more covering hair and/or promote follicular regeneration. 13. Process for the cosmetic treatment of hair, in particular to limit hair loss and/or to promote hair growth, comprising the application of at least one cosmetic composition comprising at least one extract of Iris spp. rhizomes and at least one cosmetically acceptable excipient.