Avocado unsaponifiable for use in the treatment of pathologies induced by malassezia yeast

Abstract

The present invention relates to the avocado unsaponifiable or to a composition comprising the avocado unsaponifiable for use in the prevention and / or treatment of pathologies and disorders induced by a yeast of the genus Malassezia, the avocado unsaponifiable containing at least 50% by weight of furanic lipids relative to the total mass of the avocado unsaponifiable. The present invention also relates to the cosmetic use of the avocado unsaponifiable or of a composition comprising the avocado unsaponifiable for the prevention and / or treatment of dandruff, the avocado unsaponifiable containing at least 50% by weight of furanic lipids relative to the total mass of the avocado unsaponifiable. Furthermore, the invention relates to a method for preparing the avocado unsaponifiable.

Description

[0001] UNSAPONIFIABLE AVOCADO FOR USE IN THE TREATMENT OF PATHOLOGIES INDUCED BY MALASSEZIA YEAST

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to avocado unsaponifiable matter or a composition comprising avocado unsaponifiable matter for use in the prevention and / or treatment of pathologies and disorders induced by a yeast of the genus Malassezia. The present invention also relates to the cosmetic use of avocado unsaponifiable matter or a composition comprising avocado unsaponifiable matter for the prevention and / or treatment of dandruff. Furthermore, the invention relates to a process for preparing avocado unsaponifiable matter.

[0004] CONTEXT OF THE INVENTION AND PRIOR ART

[0005] The human microbiome includes multiple and diverse microorganisms such as bacteria, viruses, and fungi. Malassezia yeast, a member of the Basidiomycetes, is part of the human commensal flora, particularly in the scalp. This yeast releases hydrolases, such as lipases and phospholipase C, which allow the production of fatty acids from the lipids of the yeast's host. In people with seborrheic dermatosis, Malassezia yeast invades the stratum corneum, and the free fatty acids generated by the release of lipases trigger an inflammatory process. Inflammation leads to hyperproliferation of the stratum corneum and incomplete differentiation of corneocytes, which impairs the functions of the stratum corneum, including its barrier function, resulting in easier access for Malassezia yeast.Malassezia yeast is involved in many skin conditions, such as seborrheic dermatitis, Malassezia folliculitis, scalp dandruff, pityriasis capitis and pityriasis versicolor.

[0006] Seborrheic dermatitis is a fairly common benign chronic erythematous scaly inflammatory dermatosis that develops in flare-ups and most often affects the scalp and face, particularly the nasolabial folds and eyebrows. One of the typical forms affects infants and manifests as yellow crusts on the scalp (cradle cap) or face.

[0007] Cradle cap is a form of infantile seborrheic dermatitis (ISD) presenting erythematous plaques with oily scales on the scalp and whose incidence is highest in the third month of life of patients. The factors for the appearance of cradle cap are diverse. Hyperproduction of sebum can be one of these factors without being a necessary cause of their appearance: it causes the adhesion of dead corneocytes to the surface of the skin and prevents their physiological desquamation. Invasion of the stratum corneum by the Malassezia yeast as described above is another of these factors. In the prior art, the therapeutic strategy used in the treatment of seborrheic dermatitis, particularly cradle cap, aims to regulate sebum production, calm skin inflammation and reduce the development of Malassezia yeast.This treatment involves the use of anti-inflammatory drugs such as topical corticosteroids and antifungals such as ketoconazole, lithium gluconate, or cyclopiroxolam. Treatment may also involve emollients such as mineral or olive oils or petroleum jelly and keratolytics such as salicylic acid.

[0008] Generally speaking, the treatments of choice for pathologies and disorders induced by a yeast of the genus Malassezia, in particular Pityriasis versicolor and seborrheic dermatitis, are antifungal and anti-inflammatory treatments. Action on sebum production is generally not sufficient to treat pathologies and disorders induced by a yeast of the genus Malassezia.

[0009] Furthermore, normal seborrheic production does not prevent the start of an abnormal growth cycle of yeasts of the Malassezia genus. Thus, a treatment acting only on sebum production, for example by inhibiting the activity of 5-alpha reductase, cannot be a treatment of choice for these disorders. In addition, sebum production is not solely controlled by the 5-alpha reductase pathway; it can be activated by other pathways or other causes such as physical or psychological stress.

[0010] Prolonged use of corticosteroids may cause side effects such as skin atrophy, striae, telangiectasia, folliculitis, hypopigmentation, and habituation, and prolonged use of antifungals may cause side effects such as contact dermatitis; in addition, other treatments have limitations of use; for example, lithium gluconate is only indicated for the treatment of immunocompetent adults.

[0011] There is therefore a real need for a composition for preventing and / or treating conditions caused by the Malassezia yeast, which can be administered topically, which does not present the aforementioned adverse effects of corticosteroids and antifungals and which can be used in children, infants and newborns.

[0012] In the context of the present invention, the Applicant has surprisingly discovered that avocado unsaponifiable matter is capable of inhibiting the growth of yeasts of the genus Malassezia.

[0013] In its international patent application WO2004 / 012496, the Applicant describes a process for obtaining an avocado unsaponifiable matter rich in furan lipids. In general, avocado unsaponifiable matters are used to treat certain connective tissue disorders such as osteoarthritis, joint pathologies such as rheumatism, or periodontal diseases, such as gingivitis or periodontitis (see for example international patent application WO2013 / 098293).

[0014] The Applicant has thus discovered that avocado unsaponifiable matter can be used in the prevention and / or treatment of pathologies and disorders induced by a yeast of the genus Malassezia, in particular in the prevention and / or treatment of seborrheic dermatitis, in particular infantile seborrheic dermatitis such as cradle cap, pityriasis capitis, Malassezia folliculitis, pityriasis versicolor and dandruff.

[0015] Indeed, avocado unsaponifiables can inhibit the growth of yeasts of the Malassezia genus and act as an anti-inflammatory, soothing agent and / or anti-itching agent.

[0016] SUMMARY OF THE INVENTION

[0017] According to a first aspect, the present invention relates to avocado unsaponifiable matter for its use in the prevention and / or treatment of pathologies and disorders induced by a yeast of the genus Malassezia, said avocado unsaponifiable matter containing at least 50% by mass of furanic lipids, preferably at least 60% by mass, relative to the total mass of the avocado unsaponifiable matter.

[0018] According to a second aspect, the present invention relates to a composition comprising avocado unsaponifiable matter for use in the prevention and / or treatment of pathologies and disorders induced by a yeast of the genus Malassezia, said avocado unsaponifiable matter containing at least 50% by mass of furan lipids, preferably at least 60% by mass, relative to the total mass of the avocado unsaponifiable matter.

[0019] According to a third aspect, the present invention relates to a cosmetic use of avocado unsaponifiable matter for the prevention and / or treatment of dandruff, said avocado unsaponifiable matter containing at least 50% by mass of furan lipids, preferably at least 60% by mass, relative to the total mass of avocado unsaponifiable matter.

[0020] According to a fourth aspect, the present invention relates to a cosmetic use of a composition comprising avocado unsaponifiable matter for the prevention and / or treatment of dandruff, said avocado unsaponifiable matter containing at least 50% by mass of furan lipids, preferably at least 60% by mass, relative to the total mass of the avocado unsaponifiable matter.

[0021] According to a fifth aspect, the present invention relates to a process for preparing the avocado unsaponifiable matter comprising at least the following steps: i. a step of heat treatment of the avocado oil concentrate, advantageously carried out at a temperature of 60°C to 90°C, preferably 80°C, ii. a step of saponification of the avocado oil concentrate in the presence of an ethanolic or aqueous alkali of the sodium hydroxide or potassium hydroxide type making it possible to obtain the avocado unsaponifiable matter, iii. optionally a step of precipitation of the soaps obtained in step ii., iv. at least one step of extraction of the product obtained in step ii. or iii. wherein the avocado unsaponifiable is purified by liquid / liquid or solid / liquid extraction with at least 50% by volume of a solvent selected from ethyl acetate, propyl acetate and butyl acetate, relative to the total volume of extraction solvents, and v.optionally an additional purification step of distillation and / or deodorization.

[0022] DEFINITIONS

[0023] For the purposes of the present invention, the term "yeast of the genus Malassezia" means any species and variety of yeast belonging to the genus Malassezia, also called the genus Pityrosporum. Examples that may be mentioned, but are not limited to, the following yeast species: Malassezia furfur, in particular strain CIP 1634.86, Malassezia globosa, Malassezia restricta, Malassezia sympodialis, Malassezia obtuse, Malassezia slooffiae, Malassezia pachydermatis and Malassezia folliculitis.

[0024] For the purposes of the present invention, “dandruff” means unsightly clumps of dead cells present on the scalp.

[0025] For the purposes of the present invention, "pityriasis versicolor" means a skin infection caused by Malassezia furfur which manifests itself as multiple scaly plaques ranging in color from white to brown to pink.

[0026] For the purposes of the present invention, "minimum inhibitory concentration (MIC)" means the smallest concentration of a compound which inhibits the growth of a given microorganism.

[0027] By "avocado oil concentrate" or "avocado concentrate" is meant avocado oil concentrated in its unsaponifiable fraction, advantageously by molecular distillation or by cold crystallization.

[0028] For the purposes of the present invention, "Malassezia folliculitis", also called Malassezia folliculitis, means an inflammatory skin disorder which typically manifests as a pruritic, follicular papulopustular rash distributed over the upper trunk of young adults; this disease of fungal etiology can mimic acne vulgaris and is also called Pityrosporum folliculitis.

[0029] Generally speaking, unsaponifiable matter is the fraction of a fatty substance which, after prolonged action of an alkaline base, remains insoluble in water and can be extracted by an organic solvent. Five major groups of substances are present in most unsaponifiable matter of vegetable oils: saturated or unsaturated hydrocarbons, aliphatic or terpenic alcohols, sterols (or "phytosterols"), tocopherols and tocotrienols, carotenoid pigments and xanthophils.

[0030] According to the invention, the term “avocado furan lipids” means furans monosubstituted in position 2 by a linear C11-C19 hydrocarbon chain, preferably C13-C17, saturated or comprising one or more ethylenic or acetylenic unsaturations. The avocado unsaponifiable according to the invention comprises at least one fraction enriched in furan lipids (fraction H) and one fraction enriched in polyhydroxylated fatty alcohols (fraction I). Fraction H appears first on a gas chromatograph of the avocado oil unsaponifiable.

[0031] The H fraction is the one which: in thin layer chromatography migrates at the head with an RF of 0.9, in high pressure liquid chromatography on silica is eluted first, appears mainly in gas phase chromatography.

[0032] The term "rich" refers to contents of these different components cited respectively above the respective average contents obtained by considering all the vegetable oils known to those skilled in the art.

[0033] DETAILED DESCRIPTION OF THE INVENTION

[0034] A first subject of the invention relates to avocado unsaponifiable matter for its use in the prevention and / or treatment of pathologies and disorders induced by a yeast of the genus Malassezia, said avocado unsaponifiable matter containing at least 50% by mass of furanic lipids, preferably at least 60% by mass, relative to the total mass of the avocado unsaponifiable matter.

[0035] A second subject of the invention relates to a composition comprising avocado unsaponifiable matter for use in the prevention and / or treatment of pathologies and disorders induced by a yeast of the genus Malassezia, said avocado unsaponifiable matter containing at least 50% by mass of furan lipids, preferably at least 60% by mass, relative to the total mass of avocado unsaponifiable matter.

[0036] According to a preferred embodiment of the invention, the pathologies and disorders induced by a yeast of the genus Malassezia are chosen from seborrheic dermatitis, in particular infantile seborrheic dermatitis such as cradle cap, pityriasis capitis, Malassezia folliculitis and pityriasis versicolor. Preferably, the pathologies and disorders induced by a yeast of the genus Malassezia are chosen from seborrheic dermatitis, in particular infantile seborrheic dermatitis such as cradle cap.

[0037] Pathologies and disorders induced by a yeast of the genus Malassezia can be chosen from the group consisting of seborrheic dermatitis, in particular infantile seborrheic dermatitis such as cradle cap, pityriasis capitis, Malassezia folliculitis, pityriasis versicolor and dandruff.

[0038] In another preferred embodiment, the avocado unsaponifiable matter contains at least 5% by mass of polyhydroxylated fatty alcohols, preferably at least 7% by mass, relative to the total mass of the avocado unsaponifiable matter.

[0039] Advantageously, the avocado unsaponifiable according to the invention contains at least 0.8% by mass of sterols, preferably at least 1%, relative to the total mass of the avocado unsaponifiable.

[0040] The preferred route of administration of the avocado unsaponifiable or the composition according to the invention is the topical route.

[0041] Advantageously, the composition comprising avocado unsaponifiable matter contains at least 0.25%, preferably 0.50% by mass of avocado unsaponifiable matter, relative to the total mass of the composition.

[0042] According to a preferred embodiment, the avocado unsaponifiable matter is capable of being obtained by a process comprising at least the following steps: i. a step of heat treatment of the avocado oil concentrate, advantageously carried out at a temperature of 60°C to 90°C, preferably 80°C, ii. a step of saponification of the avocado oil concentrate in the presence of an ethanolic or aqueous alkali of the sodium hydroxide or potassium hydroxide type, making it possible to obtain the avocado unsaponifiable matter, iii. optionally a step of precipitation of the soaps obtained in step ii., iv. at least one step of extraction of the product obtained in step ii. or iii. wherein the avocado unsaponifiable is purified by liquid / liquid or solid / liquid extraction with at least 50% by volume of a solvent selected from ethyl acetate, propyl acetate and butyl acetate, relative to the total volume of extraction solvents, preferably the solvent is ethyl acetate, and v.optionally an additional purification step of distillation and / or deodorization.

[0043] A third subject of the invention relates to the cosmetic use of avocado unsaponifiable matter for the prevention, reduction and / or treatment of dandruff, said avocado unsaponifiable matter containing at least 50% by mass of furan lipids, preferably at least 60% by mass, relative to the total mass of avocado unsaponifiable matter.

[0044] A fourth subject of the invention relates to the cosmetic use of a composition comprising avocado unsaponifiable matter for the prevention, reduction and / or treatment of dandruff, said avocado unsaponifiable matter containing at least 50% by mass of furanic lipids, preferably at least 60% by mass, relative to the total mass of avocado unsaponifiable matter.

[0045] A particular embodiment of the invention relates to avocado unsaponifiable matter or a composition comprising avocado unsaponifiable matter for use in preventing, reducing and / or treating dandruff, said avocado unsaponifiable matter containing at least 50% by mass of furan lipids, preferably at least 60% by mass, relative to the total mass of the avocado unsaponifiable matter. The dandruff is advantageously treated on a healthy body and a healthy scalp. In another preferred embodiment, the avocado unsaponifiable matter contains at least 5% by mass of polyhydroxylated fatty alcohols, preferably at least 7% by mass, relative to the total mass of the avocado unsaponifiable matter.

[0046] Advantageously, the avocado unsaponifiable according to the invention contains at least 0.8% by mass of sterols, preferably at least 1%, relative to the total mass of the avocado unsaponifiable.

[0047] The preferred route of administration of the avocado unsaponifiable or the composition according to the invention is the topical route.

[0048] Advantageously, the composition comprising avocado unsaponifiable matter contains at least 0.25%, preferably 0.50% by mass of avocado unsaponifiable matter relative to the total mass of the composition.

[0049] According to a preferred embodiment, the avocado unsaponifiable matter is capable of being obtained by a process comprising at least the following steps: i. a step of heat treatment of the avocado oil concentrate, typically carried out at a temperature of 60°C to 90°C, preferably 80°C, ii. a step of saponification of the avocado oil concentrate in the presence of an ethanolic or aqueous alkali of the sodium hydroxide or potassium hydroxide type making it possible to obtain the avocado unsaponifiable matter, iii. optionally a step of precipitation of the soaps obtained in step ii., iv. at least one step of extraction of the product obtained in step ii. or iii. wherein the avocado unsaponifiable is purified by liquid / liquid or solid / liquid extraction with at least 50% by volume of a solvent selected from ethyl acetate, propyl acetate and butyl acetate, relative to the total volume of extraction solvents, preferably the solvent is ethyl acetate, and v.optionally an additional purification step of distillation and / or deodorization.

[0050] The solvent system (extraction solvent) of step iv is preferably ethyl acetate.

[0051] The composition which allows the implementation of the invention comprises a pharmaceutically or dermatologically or cosmetically acceptable support, that is to say a support compatible with the skin and can be presented in all the galenic forms normally used for topical application, in particular in the form of an aqueous, hydroalcoholic or oily solution, an oil-in-water or water-in-oil or multiple emulsion, an aqueous or oily gel, a liquid anhydrous product, a dispersion of oil in an aqueous phase using spherules, these spherules being able to be polymeric nanoparticles such as nanospheres and nanocapsules or better still lipid vesicles of ionic and or non-ionic type, a transdermal device or in any other form for topical application.This composition can be more or less fluid and have the appearance of a white or colored cream, an ointment, a milk, a lotion, a serum, a paste, a mousse, a gel, a shampoo, a conditioner.

[0052] Advantageously, the pharmaceutically, dermatologically or cosmetically acceptable medium is a cream.

[0053] The composition according to the invention may also contain the usual adjuvants in the pharmaceutical or dermatological or cosmetic fields, such as hydrophilic or lipophilic gelling agents, hydrophilic or lipophilic active agents, thickeners, preservatives, antioxidants, solvents, perfumes, chelating agents, odor absorbers, chemical or mineral filters, mineral pigments, surfactants, polymers, silicone oils and coloring matters. The quantities of these different adjuvants are those conventionally used in the fields considered, for example from 0.01% to 20% of the total weight of the composition. These adjuvants, depending on their nature, may be introduced into the fatty phase, into the aqueous phase, into the lipid vesicles and / or into the nanoparticles.

[0054] Oils that can be used in the compositions for implementing the invention include mineral oils, oils of plant origin (apricot oil, sunflower oil, plum oil), oils of animal origin, synthetic oils, silicone oils and fluorinated oils (perfluoropoly ethers). Fatty alcohols (cetyl alcohol), fatty acids and waxes (beeswax) can also be used as fats.

[0055] As emulsifiers and co-emulsifiers which can be used in the invention, mention may be made, for example, of fatty acid and polyethylene glycol esters such as PEG-40 stearate, PEG-100 stearate, fatty acid and polyol esters such as glyceryl stearate and sorbitan tristearate.

[0056] Examples of hydrophilic gelling agents include, in particular, carboxyvinyl polymers (carbomer), acrylic copolymers such as acrylate / alkylacrylate copolymers, polyacrylamides, polysaccharides, natural gums and clays, and, as lipophilic gelling agents, examples of modified clays such as bentones, metal salts of fatty acids, hydrophobic silica and polyethylenes.

[0057] The methods of administration, dosages and optimal galenic forms of the compounds and compositions according to the invention can be determined according to the criteria generally taken into account in establishing a pharmaceutical or dermatological or cosmetic treatment adapted to a patient such as for example the extent of the area of ​​skin to be treated, tolerance to the treatment, skin type.

[0058] Advantageously, the unsaponifiable avocado according to the invention can be obtained according to the processes described in international patent application WO2004 / 012496, patent FR2678632 and in international patent application WO2013 / 014344.

[0059] The unsaponifiable avocado can, for example, be obtained from an avocado concentrate treated according to the following process: saponification of the avocado concentrate in the presence of an ethanolic alkali such as sodium hydroxide or potassium hydroxide; washing with water; purification by liquid / liquid extraction in the presence of a solvent such as dichloroethane (DCE) or methyl isobutyl ketone (MIBK) (process described in patent FR2678632 for DCE and in patent application WO2013 / 014344 for MIBK); the solvent and residual impurities can be removed by distillation / deodorization in order to obtain a purified unsaponifiable fraction.

[0060] The avocados used as a basis for the preparation of avocado oil may preferably undergo a preliminary dehydration or drying step, advantageously carried out at a temperature between -50°C and 75°C. The methods for extracting avocado oil are known to those skilled in the art. Avocado oil may in particular be extracted by cold pressing or using a solvent at low temperature.

[0061] The avocado oil concentrate itself can be obtained through vacuum molecular distillation (typically between 10' 3 and 10 1 mbar) and at a distillation temperature advantageously between 150°C and 350°C, typically between 180°C and 260°C, or by cold crystallization. The concentrate obtained is then advantageously subjected to heat treatment at a temperature between 40 and 150°C, for example between 80 and 130°C.

[0062] The present invention also relates to a non-therapeutic cosmetic hair care method for preventing and / or treating dandruff, consisting of administering an avocado unsaponifiable or a composition comprising the avocado unsaponifiable as defined above, in particular the administration consists of applying said unsaponifiable or said composition comprising it to the hair.

[0063] The invention further relates to a method for preventing and / or treating pathologies and disorders induced by a yeast of the genus Malassezia, comprising the administration, in particular the topical administration, of an effective amount of an avocado unsaponifiable or a composition comprising the avocado unsaponifiable as defined above, to a subject in need thereof. The pathologies and disorders induced by a yeast of the genus Malassezia are as defined above.

[0064] The cosmetic uses and cosmetic care methods according to the present invention are typically carried out on healthy skin or healthy parts of the body and are not therapeutic.

[0065] The invention relates in particular to the treatment of pathologies and disorders induced by a yeast of the genus Malassezia.

[0066] Another subject of the invention relates to a process for preparing the unsaponifiable avocado comprising at least the following steps: i. a step of heat treatment of the avocado oil concentrate advantageously carried out at a temperature of 60°C to 90°C, preferably 80°C, ii. a step of saponification of the avocado oil concentrate in the presence of an ethanolic or aqueous alkali of the soda or potash type making it possible to obtain the unsaponifiable avocado, iii. optionally a step of precipitation of the soaps obtained in step ii., iv. at least one step of extraction of the product obtained in step ii. or iii. wherein the avocado unsaponifiable is purified by liquid / liquid or solid / liquid extraction with at least 50% by volume of a solvent selected from ethyl acetate, propyl acetate and butyl acetate, relative to the total volume of extraction solvents, and v.optionally an additional purification step of distillation and / or deodorization.

[0067] Preferably, the solvent of step iv. is ethyl acetate.

[0068] Alternatively, the heat treatment of step i. may be carried out on the avocado oil before the concentration step and / or on the avocados used as the basis for the preparation of the oil.

[0069] The following examples are intended to illustrate the present invention in a non-limiting manner.

[0070] EXAMPLES

[0071] Example 1: Determination of the minimum inhibitory concentration of Malassezia fur- fur in liquid medium of avocado unsaponifiables and other products

[0072] This example aims to study the effect of an avocado unsaponifiable according to the invention on Malassezia furfur compared to another avocado product, avocado oil concentrate and two other soybean products, soybean oil concentrate and soybean unsaponifiable.

[0073] Process for the preparation of soybean oil concentrate

[0074] Crude or refined soybean oil is processed by molecular distillation under high vacuum (between 10' 3 and 10' 2 mbar) and at a distillation temperature between 200°C and 300°C.

[0075] A compound as described in the table below is obtained. Table 1

[0076] Process for the preparation of soybean unsaponifiable matter

[0077] A soy concentrate as obtained by the process described above or a co-product from the refining of soybean oil (see patent application WO2012 / 104319) is treated according to the following process: saponification of the soy concentrate in the presence of an ethanolic alkali such as sodium hydroxide or potassium hydroxide in order to remove residual fatty acids; washing with water; - purification by liquid / liquid extraction in the presence of a solvent such as dichloroethane (DCE) or methyl isobutyl ketone (MIBK) (process described in patent application WO2012 / 104319 for MIBK); the solvent and residual impurities are removed by distillation / deodorization in order to obtain a purified unsaponifiable fraction as described in the table below. Table 2

[0078] Process for preparing avocado concentrate

[0079] The crude avocado oil obtained according to the process described in application WO2004 / 012496 is treated by molecular distillation under high vacuum (approximately 5.10' 3 mbar) and at a distillation temperature of approximately 250°C. The concentrate obtained is subjected to a temperature of 80°C.

[0080] A compound is obtained as described in the table below.

[0081] Table 3 Process for the preparation of avocado unsaponifiable matter

[0082] The first step consists of the saponification of an avocado concentrate obtained using the process described above. To this end, the avocado oil concentrate, followed by water and 50% potash, are successively introduced into a reactor. The system is then brought to reflux with stirring, and then, after cooling, sodium chloride is added. A separation step by filtration or decantation is then carried out in order to recover the fraction comprising the unsaponifiable matter. This precipitate is then extracted with ethyl acetate. The unsaponifiable matter is then recovered by evaporation of the solvent. The product is then subjected to a deodorization step by injecting steam at 100°C under a vacuum of between 30 and 50 mbar.

[0083] Table 4

[0084] Protocol

[0085] The determination of the minimum inhibitory concentration (MIC) of the different products tested is carried out using a method adapted to liquid media in 96-well plates. The MIC measurement study is carried out using GLYcoDiag technology, using the microbial strain Malassezia furfur (American Type Culture Collection (ATCC) Reference: 14521) as the organism. The cultures are reconstituted according to the instructions of the collection center supplying the reference strain. The following products were tested: Soy concentrate, Soy unsaponifiables, Avocado unsaponifiables, Avocado concentrate.

[0086] Preparation of samples and test microorganisms

[0087] The different products listed above are previously dissolved in olive oil at the following concentrations: final concentrations in culture medium (expressed as mass percentages): 1%, 0.5%, 0.25%, 0.1%, 0.05% and 0.01%.

[0088] Analytical controls are prepared and then used in an identical manner to the tested samples: a control corresponding to the microbiological medium alone; a control consisting of olive oil prepared at 5% (m / m) directly in the microbiological medium associated with each microbial strain; a control consisting of Phenoxyethanol® prepared at 5% (m / m) directly in the microbiological medium associated with each microbial strain. Phenoxyethanol is a compound known to inhibit the growth of M. furfur.

[0089] In order to determine the MIC of the tested product, it is tested in serial dilutions on 6 dilutions directly in the culture medium intended to promote the growth of the M. furfur strain (96-well microplates). Then, each dilution point is contaminated with the tested strain at a rate of approximately 1.10 5cfu / mL per well. Finally, the tests are incubated for 48 hours at 32.5°C ± 2.5°C, taking care to respect the respiratory type of the strain which is facultative aeroanaerobic.

[0090] Results

[0091] At the end of the incubation period, the presence or absence of a cloudiness reveals the state of microbial growth. The last dilution corresponding to the absence of growth of M. furfur is retained as the minimum inhibitory concentration (MIC).

[0092] The study was conducted in n = 3. The results of the study are presented in the following table.

[0093] Table 5

[0094] X: No inhibition detected

[0095] An MIC of 0.25% was demonstrated with the avocado unsaponifiable on the M. furfur strain; this MIC is lower than that obtained with phenoxyethanol, a known antifungal. On the other hand, neither of the two concentrate samples tested, i.e. the soy concentrate and the avocado concentrate, showed inhibitory activity on the M. furfur strain. It is interesting to note that the soy unsaponifiable also has no inhibitory activity on M. furfur, thus demonstrating the specificity of the activity of the avocado unsaponifiable according to the invention.

Claims

Claims 1. Avocado unsaponifiable matter for use in the prevention and / or treatment of pathologies and disorders induced by a yeast of the genus Malassezia, said avocado unsaponifiable matter containing at least 50% by mass of furanic lipids, preferably at least 60% by mass, relative to the total mass of the avocado unsaponifiable matter.

2. Composition comprising avocado unsaponifiable matter for use in the prevention and / or treatment of pathologies and disorders induced by a yeast of the genus Malassezia, said avocado unsaponifiable matter containing at least 50% by mass of furan lipids, preferably at least 60% by mass, relative to the total mass of the avocado unsaponifiable matter.

3. Composition comprising avocado unsaponifiable matter for use according to claim 2, characterized in that the composition contains at least 0.25%, preferably 0.50% by mass of avocado unsaponifiable matter, relative to the total mass of the composition.

4. Unsaponifiable avocado for its use according to claim 1 or composition comprising unsaponifiable avocado for its use according to claim 2 or 3, characterized in that the pathologies and disorders induced by a yeast of the genus Malassezia are chosen from the group consisting of seborrheic dermatitis, in particular infantile seborrheic dermatitis such as cradle cap, pityriasis capitis, Malassezia folliculitis, pityriasis versicolor and dandruff.

5. Unsaponifiable avocado for its use according to claim 1 or 4 or composition comprising unsaponifiable avocado for its use according to any one of claims 2 to 4, characterized in that the unsaponifiable avocado contains at least 5% by mass of polyhydroxylated fatty alcohols, preferably at least 7% by mass, relative to the total mass of the unsaponifiable avocado.

6. Unsaponifiable avocado for its use according to any one of claims 1 and 4 to 5 or composition comprising unsaponifiable avocado for its use according to any one of claims 2 to 5, characterized in that the unsaponifiable avocado or the composition comprising unsaponifiable avocado is administered topically.

7. Unsaponifiable avocado for use according to any one of claims 1 and 4 to 6 or composition comprising unsaponifiable avocado for use according to any one of claims 2 to 6, characterized in that the unsaponifiable avocado is capable of being obtained by a process comprising at least the following steps: i. a step of heat treatment of the avocado oil concentrate, advantageously carried out at a temperature of 60°C to 90°C, preferably 80°C, ii. a step of saponification of the avocado oil concentrate in the presence of an alkali ethanolic or aqueous solution of the soda or potash type, making it possible to obtain the unsaponifiable avocado, iii. optionally a step of precipitation of the soaps obtained in step ii., iv. at least one step of extraction of the product obtained in step ii. or iii. in which the unsaponifiable avocado is purified by liquid / liquid or solid / liquid extraction with at least 50% by volume of a solvent chosen from ethyl acetate, propyl acetate and butyl acetate, relative to the total volume of extraction solvents, and v. optionally an additional purification step of distillation and / or deodorization.

8. A process for preparing avocado unsaponifiable matter comprising at least the following steps: i. a step of heat treatment of the avocado oil concentrate, advantageously carried out at a temperature of 60°C to 90°C, preferably 80°C, ii. a step of saponification of the avocado oil concentrate in the presence of an ethanolic or aqueous alkali of the sodium hydroxide or potassium hydroxide type, making it possible to obtain the avocado unsaponifiable matter, iii. optionally a step of precipitation of the soaps obtained in step ii., iv. at least one step of extraction of the product obtained in step ii. or iii. in which the avocado unsaponifiable matter is purified by liquid / liquid or solid / liquid extraction with at least 50% by volume of a solvent chosen from ethyl acetate, propyl acetate and butyl acetate, relative to the total volume of extraction solvents, and v. optionally an additional purification step of distillation and / or deodorization.

9. Process for preparing the avocado unsaponifiable according to claim 8, wherein the extraction solvent of step iv. is ethyl acetate.

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