WO2015092674A1

WO2015092674A1 - Cosmetic use of an essential oil of laserpitium siler l. for lightening keratin materials

Info

Publication number: WO2015092674A1
Application number: PCT/IB2014/066958
Authority: WO
Inventors: Eric ABISSET; Corinne Ferraris
Original assignee: L'oreal
Priority date: 2013-12-20
Filing date: 2014-12-16
Publication date: 2015-06-25
Also published as: FR3015281A1; FR3015281B1

Abstract

The present invention relates to the cosmetic use of the essential oil of Laserpitium siler L. as an active agent for depigmenting, lightening and/or bleaching keratin materials, in particular the skin of the face and/or of the body, and/or for preventing, reducing and/or treating a modification of the skin complexion or of the colour of the semi-mucous membranes. It also relates to a non-therapeutic cosmetic process for depigmenting, lightening and/or bleaching keratin fibres, and/or for preventing, reducing and/or treating a modification of the skin complexion or the colour of the semi-mucous membranes.

Description

"Cosmetic use of an essential oil of Laserpitium siler L. for lightening keratin materials"

The present invention relates to the field of cosmetic products, more particularly intended for caring for keratin materials, in particular caring for the skin of the face and/or of the body.

More particularly, the present invention aims to propose the use of a novel active agent for effectively depigmenting and/or lightening, or even bleaching, keratin materials, in particular the skin of the face and/or of the body and/or improving the complexion, in particular the homogeneity thereof and the radiance thereof.

The colour of human skin is mainly determined by the nature and the concentration of a pigment, melanin. There are two types of melanin in epidermal cells, eumalanin, which is a brown-black coloured pigment, and pheomelanin, which is a yellow- orange coloured pigment. Melanin is synthesized by specific dendritic cells, called melanocytes, located in the basal layer of the epidermis. Melanogenesis, i.e. the formation of melanin, takes place in specific organelles, the melanosomes, which, loaded with melanin, are transferred to the neighbouring epidermal cells, the keratinocytes, via the dendrites.

The mechanism of melanogenesis is particularly complex and schematically involves the following main steps:

Tyrosine— > Dopa— > Dopaquinone— > Dopachrome— > Melanin Inside the melanosomes, three enzymes, namely tyrosinase, Tyrp 1 (for Tyrosinase-related protein 1) and Dct/Tyrp2 (for DOPAchrome tautomerase/Tyrosinase- related protein 2), play a major role in melanin production. More particularly, tyrosinase is the essential enzyme which regulates the first steps of eumelanin and pheomelanin synthesis.

The pigmentation of the skin of the face and/or of the body, and more particularly the constitutive pigmentation of the skin, depends on various factors, such as the seasons of the year, race and sex.

In addition, at various periods of their life, some people experience the appearance on their skin, and more in particular on the hands, of darker and/or more coloured spots, which give the skin a heterogeneity. These spots are also due to a high concentration of melanin in the keratinocytes located at the surface of the skin. Thus, when the pigmentation process is modified, this can result in pigmentation defects, hypopigmentations, or, conversely, in excess pigmentation, hyperpigmentations. Among the benign hyperpigmentation disorders, characterized by an abnormal accumulation (excluding tanning) of melanin, mention may be made of actinic lentigo (also called senile or solar lentigo, senile spots or age spots, or else commonly known as "senile keratoma", "graveyard daisies" or "graveyard flowers"), lentigines, freckles, melasmas, such as idiopathic melasmas occurring during pregnancy ("pregnancy mask" or chloasma) or during oestro-progestogen contraception, pigmentary sequelae of acne, post-inflammatory pigmentation, phytodermatitis, pigmentation associated with the plant poison ivy or else benign dyschromias of the face.

These benign skin pigmentation disorders are generally considered to be unattractive.

Many processes, mainly for cosmetic purposes, have therefore been developed in order to attempt to eliminate or reduce the presence of these pigmentation disorders. The elimination or reduction of the presence of these disorders is normally based on the application of depigmenting treatments based on reducing the melanin synthesis activity in melanocytes. Depigmenting molecules are to be distinguished from anti-pigmenting molecules which limit the action of the stresses responsible for pigmentation, which are due for example to ultraviolet radiation.

More specifically, a molecule is acknowledged to be 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 steps of melanin biosynthesis, either by inhibiting one of the enzymes involved in melanogenesis, or by inserting itself as a structural analogue of one of the chemical compounds of the melanin synthesis chain, which chain can then be blocked, thus ensuring depigmentation.

One of the main approaches explored to date is based on the inhibition of tyrosinase. The aim of these treatments is to reduce or even stop pigment synthesis.

The main known depigmenting substances are hydroquinone and derivatives thereof, in particular ethers thereof such as hydroquinone monomethyl ether or monoethyl ether, kojic acid, arbutin, iminophenols, ascorbic acid and derivatives thereof, the combination of carnitine and quinone, aminophenol derivatives, and benzothiazole derivatives, natural extracts, corticoids, etc. However, there are major drawbacks associated with the use of the abovementioned depigmenting agents. Indeed, the depigmenting substances may exhibit in particular a certain instability, a poor effectiveness at low concentration, a biological activity which affects other functions, or toxic or allergenic properties.

For example, with regard to hydroquinone and derivatives thereof, although these compounds exhibit a definite effectiveness, they are unfortunately not free of side effects due to their toxicity, which can make their use difficult, or even dangerous. This toxicity comes from the fact that they intervene on fundamental mechanisms of melanogenesis by killing cells, which may then disrupt their biological environment and, consequently, force the skin to evacuate them, producing toxins.

Thus, the use of harmless topical depigmenting substances which exhibit a good degree of effectiveness is quite particularly sought with a view to effectively depigmenting and/or lightening, or even bleaching, keratin materials, in particular the skin, and/or to preventing, reducing and/or treating a modification of the skin complexion or of the colour of the semi-mucous membranes, i.e. in particular to improving the homogeneity of the complexion and/or reviving the radiance of the complexion.

There thus remains the need for a new bleaching agent for keratin materials, in particular the skin, which also make it possible in particular to improve the homogeneity of the complexion and to revive the radiance of the complexion, which have an action that is as effective as those which are known, but which do not have their drawbacks, i.e. which are stable, non-toxic to the skin and effective even at low concentration.

In this regard, the applicant company has, surprisingly and unexpectedly, discovered that the essential oil of Laserpitium siler L. exhibits good depigmenting activity and also an action which makes it possible to prevent, reduce and/or treat a modification of the skin complexion or of the colour of the semi-mucous membranes, i.e. in particular an activity which makes it possible to improve the homogeneity of the complexion and to revive the radiance of the complexion, even at low concentration.

Thus, according to a first subject, the present invention relates to the cosmetic use of the essential oil of Laserpitium siler L. as an active agent for depigmenting, lightening and/or bleaching keratin materials, in particular the skin of the face and/or of the body, and/or for preventing, reducing and/or treating a modification of the skin complexion or of the colour of the semi-mucous membranes. The inventors have in fact demonstrated that the essential oil of Laserpitium siler L. exhibits a depigmenting, lightening or even bleaching activity on keratin materials, in particular the skin. More particularly, it has been shown, as detailed in the experimental section hereinafter, that the essential oil of Laserpitium siler L. acts on the constitutive pigmentation of the skin and therefore on melanin synthesis.

One of the advantages of the essential oil of Laserpitium siler L. according to the invention is that it is obtained from a natural active agent.

In particular, according to this first aspect, the present invention aims to protect the cosmetic use of the essential oil of Laserpitium siler L. for the treatment of at least one unattractive benign pigmentation disorder chosen from hyperpigmentations, actinic lentigo, lentigines, freckles, chloasma, melasmas, idiopathic melasmas occurring during pregnancy or during oestro-progestogen contraception, pigmentary sequelae of acne, postinflammatory pigmentation, phytodermatitis, pigmentation associated with the plant poison ivy, and benign dyschromias of the face.

Likewise according to this first aspect, the present invention relates to the cosmetic use of the essential oil of Laserpitium siler L. for improving the homogeneity of the complexion and/or reviving the radiance of the complexion.

The essential oil of Laserpitium siler L. is not, at the current time, known to be used for depigmenting, lightening or even bleaching keratin materials, in particular the skin, nor for improving the homogeneity of the complexion, nor for reviving the radiance of the complexion.

The present invention also aims to protect a non-therapeutic cosmetic treatment process for depigmenting, lightening and/or bleaching keratin materials, in particular the skin of the face and/or the body, and/or for preventing, reducing and/or treating a modification of the skin complexion or of the colour of the semi-mucous membranes, comprising at least one step consisting in applying, to the skin of the face and/or the body, at least one composition comprising essential oil of Laserpitium siler L..

The composition suitable for the invention, namely intended for the implementation of the invention, is a cosmetic composition and therefore comprises a physiologically acceptable medium.

For the purposes of the present invention, the term "preventing" or "prevention" is intended to mean at least partially reducing the risk of occurrence of a given phenomenon, i.e., in the present invention, a modification of the skin complexion or of the colour of the semi-mucous membranes.

ESSENTIAL OIL OF LASERPITIUM SILER L.

A composition that is suitable for the invention comprises essential oil of Laserpitium siler L..

Laserpitium siler L., also known as Laser siler, sermontain or mountain siler, is a plant belonging to the Apiacea family. It is a hardy plant 40 to 130 cm in height which bears an imposing umbel during the flowering season (July- August).

This plant is found in dry rocky and prairie areas of the semi-mountainous regions of southern Europe at an altitude of between 400 m and 2000 m.

This plant is more particularly found in France, in particular in the Jura, the Alps, the Cevennes, the Corbieres and the Pyrenees and more particularly in the Vercors, the Gap region and the Briancon region.

According to the definition given in international standard ISO 9235 and adopted by the Commission of the European Pharmacopoeia, an essential oil is an odoriferous product generally of complex composition, obtained from a botanically defined plant raw material, either by steam distillation, or by dry distillation, or via an appropriate mechanical process without heating (cold pressing). The essential oil is generally separated from the aqueous phase via a physical process which does not result in any significant change in the composition.

Methods for obtaining essential oils

The choice of technique depends mainly on the raw material: its original state and its characteristics, its actual nature. The "essential oil/plant raw material" yield may be extremely variable depending on the plant: 15 ppm to more than 20%. This choice conditions the characteristics of the essential oil, in particular viscosity, colour, solubility, volatility, richness or poorness in certain constituents.

Steam distillation corresponds to the vapourization, in the presence of steam, of a sparingly water-miscible substance. The raw material is placed in contact with boiling water or steam in an alambic. The steam entrains the essential oil vapour, which is condensed in the condenser and recovered as a liquid phase in a Florentine vase (or essence jar), where the essential oil is separated from the water by settling. The aqueous distillate that remains after the steam distillation, once the separation of the essential oil has been performed, is known as the "aromatic water" or "hydrolate" or "distilled floral water".

Dry distillation consists in obtaining the essential oil by distillation of woods, barks or roots, without addition of water or steam, in a closed chamber designed so that the liquid is recovered at the bottom. Cade oil is the best known example of a product obtained in this way.

Preferably, an essential oil of Laserpitium siler L. according to the invention is prepared via the steam distillation method.

Physicochemical characteristics

Essential oils are generally volatile and liquid at ambient temperature, which distinguishes them from "set" oils. They are more or less coloured and their density is generally less than that of water. They have a high refractive index and most of them deflect polarized light. They are liposoluble and soluble in the usual organic solvents, distillable with steam, and very sparingly soluble in water.

Plant raw materials

An essential oil of Laserpitium siler L. according to the invention may be prepared from any plant material derived from at least one Laserpitium siler L. cultivated in vivo or derived from in vitro cultivation.

The term "in vivo cultivation" is intended to mean any cultivation of standard type, i.e. in soil in the open air or in a greenhouse, or alternatively without soil.

The term "in vitro cultivation" is intended to mean all the techniques known to those skilled in the art for artificially obtaining a plant or a plant part. The selection pressure imposed by the physicochemical conditions during the growth of plant cells in vitro makes it possible to obtain a standardized plant material that is available throughout the year, in contrast with plants cultivated in vivo.

The essential oil of Laserpitium siler L. used in the present invention may be obtained from any plant material derived from this whole plant or from any part of this plant, for instance the leaves, stems, roots, flowers, petals, seeds, umbels, fruit and buds, which are in various states of dryness (dry, withered or fresh form). Preferably, an essential oil of Laserpitium siler L. according to the invention is obtained from the leaves and/or umbels and/or seed-bearing umbels and/or fruit seeds of Laserpitium siler L., more preferentially from the leaves and/or umbels, and even more preferentially from the seed-bearing umbels.

According to a preferred embodiment, an essential oil of Laserpitium siler L. according to the invention is obtained from the umbels and/or the seed-bearing umbels, and more preferentially from the seed-bearing umbels.

According to a preferred embodiment, an essential oil of Laserpitium siler L. according to the invention is obtained from the leaves.

Advantageously, the umbels or seeds may be predried and ground.

An essential oil in accordance with the invention may be prepared according to the techniques mentioned above.

As mentioned above, preferably, an essential oil in accordance with the invention is obtained according to the standard technique of steam distillation.

Advantageously, an essential oil according to the invention is obtained from the fruit umbels of Laserpitium siler L. by hydrodistillation or from the leaves by steam distillation on glass distillation apparatus (such as 4-litre Clevenger apparatus), such as the apparatus defined in the European Pharmacopoeia for the determination of the essential oil of a plant material.

Preferentially, the essential oil according to the invention is prepared from the seed-bearing umbels of Laserpitium siler L. by hydrodistillation.

According to another preferred embodiment, an essential oil in accordance with the invention is obtained from leaves, preferably by means of a steam distillation process.

The chemical composition of the essential oil of Laserpitium siler L. in accordance with the invention thus obtained may be analysed by standard techniques known to those skilled in the art, such as gas chromatography GC analysis, chromatographic analysis with flame ionization detection, known as GC-FID, or GC/MS analysis, which consists in using a mass spectrometer coupled to a gas chromatograph.

Advantageously, the essential oil of Laserpitium siler L. mainly contains limonene, perillaldehyde and chamazulene. These three compounds are well known. Limonene, the empirical formula of which is C₁₀H₁₆, is a chiral terpene hydrocarbon. At ambient temperature, it is a colourless liquid with a fresh, clean, orange odour characteristic of citrus fruit. Limonene is generally present in the essential oil of Laserpitium siler L. in a content ranging from 40% to 80% by weight and preferably from 50% to 70%) by weight relative to the total weight of said essential oil.

Perillaldehyde or perilla aldehyde, the empirical formula of which is C₁₀H₁₄O , is a monoterpene comprising an aldehyde function. Perillaldehyde is generally present in the essential oil of Laserpitium siler L. in a content ranging from 15% to 40% by weight and preferably from 20% to 35% by weight relative to the total weight of said essential oil.

Chamazulene is a blue-coloured sesquiterpene hydrocarbon. Chamazulene is generally present in the essential oil of Laserpitium siler L. in a content of less than or equal to 10% by weight and preferably less than or equal to 5% by weight relative to the total weight of said essential oil.

An essential oil in accordance with the invention may be used as such, i.e. alone, or may be introduced into a cosmetic composition.

According to a first embodiment, the essential oil is obtained from the umbels and even more preferentially from the seed-bearing umbels.

According to this first embodiment, the essential oil of Laserpitium siler L. in accordance with the invention comprises an amount of limonene ranging from 40% to 80% by weight and preferably ranging from 50% to 70% by weight relative to the total weight of said essential oil, an amount of perillaldehyde ranging from 15% to 40% by weight and preferably ranging from 20% to 35% by weight relative to the total weight of said essential oil, and an amount of chamazulene of less than or equal to 10% and preferably less than or equal to 5% by weight relative to the total weight of said essential oil.

According to a second embodiment, the essential oil is obtained from the leaves.

According to this second embodiment, the essential oil of Laserpitium siler L. according to the invention comprises at least 40%, preferably at least 50% by weight and better still at least 65% by weight of monoterpenes chosen from limonene, myrcene, sabinene, γ-terpinene, para-cymene and a-pinene, and at least 5% by weight and preferably at least 15% by weight of sesquiterpenes chosen from chamazulene, germacrene D and trans-P-caryophyllene. COMPOSITION

The composition that is suitable for the invention is intended for cosmetic application.

According to the present invention, the essential oil of Laserpitium siler L. may be used in an amount sufficient for obtaining the desired effect, i.e. in an amount sufficient for depigmenting, lightening and/or bleaching keratin materials, in particular the skin of the face and/or of the body, and/or for preventing, reducing and/or treating a modification of the skin complexion or of the colour of the semi-mucous membranes, in particular improving the homogeneity of the complexion and/or reviving the radiance of the complexion.

The essential oil of Laserpitium siler L. suitable for the invention acts as a depigmenting agent on the constitutive pigmentation of the skin. In other words, the essential oil of Laserpitium siler L. acts directly on melanin synthesis. Its depigmenting property is to be distinguished from the anti-pigmenting property of certain molecules. Anti-pigmenting molecules make it possible in particular to combat hyperpigmentations induced by an oxidative stress that can come from exposure to the sun or from pollution or from smoke.

An essential oil suitable for the invention can also make it possible to depigment and/or lighten body hairs, eyelashes, head hair, and also the lips and/or the nails.

Preferably, the essential oil of Laserpitium siler L. is used in a cosmetic composition in a content ranging from 0.0001% to 10% by weight, preferably from 0.001%) to 1%) by weight, most preferentially from 0.01%> to 0.5% by weight and even better still from 0.01%> to 0.1%> by weight relative to the total weight of the cosmetic composition.

It can be administered in particular topically or orally.

As indicated previously, an essential oil of Laserpitium siler L. according to the present invention mainly contains limonene, perillaldehyde and chamazulene.

Thus according to a particular embodiment, a cosmetic composition that is suitable for the invention comprises an essential oil of Laserpitium siler L. in accordance with the invention comprising an amount of limonene ranging from 40% to 80% by weight and preferably ranging from 50%> to 70% by weight relative to the total weight of said essential oil, an amount of perillaldehyde ranging from 15% to 40% by weight and preferably ranging from 20% to 35% by weight relative to the total weight of said essential oil, and an amount of chamazulene of less than or equal to 10% and preferably less than or equal to 5% by weight relative to the total weight of said essential oil.

According to another embodiment, an essential oil of Laserpitium siler L. according to the invention comprises at least 40%, preferably at least 50% by weight and better still at least 65% by weight of monoterpenes chosen from limonene, myrcene, sabinene, γ-terpinene, para-cymene and a-pinene, and at least 5% by weight and preferably at least 15% by weight of sesquiterpenes chosen from chamazulene, germacrene D and trans-P-caryophyllene.

Preferably, an essential oil according to the invention, when it is present in a composition, may be formulated in a physiologically acceptable medium.

The term "physiologically acceptable medium" is intended to mean a medium that is compatible with all keratin materials such as the skin, the scalp, the nails, the mucous membranes, the eyes and the hair, or any other area of bodily skin. A physiologically acceptable medium is preferentially a cosmetically acceptable medium, i.e. it is entirely compatible with the route of administration under consideration.

When the composition is intended to be administered topically, such a medium is considered as being physiologically acceptable when it does not cause any stinging, tautness or redness that is unacceptable to the user.

Advantageously, a composition that is suitable for the invention, comprising an essential oil of Laserpitium siler in accordance with the invention, is intended for topical administration.

A composition that is suitable for the invention may be in any galenical form normally used in the cosmetic field.

It may in particular be in the form of an aqueous or aqueous-alcoholic solution, which is optionally gelled, a dispersion of the lotion type, which is optionally a two-phase lotion, an oil-in-water or water-in-oil or multiple emulsion, an aqueous gel, a gelled or non-gelled oil, a dispersion of oils in an aqueous phase, in particular with the aid of spherules, these spherules possibly being polymer particles or, better still, lipid vesicles of ionic and/or non-ionic type, or alternatively in the form of a powder, a serum, a paste or a flexible stick. It may be of solid, pasty or more or less fluid liquid consistency.

Thus, the composition may comprise any constituent usually used in the envisaged topical application and administration.

Mention may be made in particular of water, solvents, oils of mineral, animal and/or plant origin, in particular as detailed hereinbelow, waxes, in particular as described hereinbelow, pigments, fillers, surfactants, thickeners, gelling agents and preserving agents, and mixtures thereof.

A composition suitable for the invention may also contain various adjuvants commonly used in the cosmetics field, such as sequestrants, odour absorbers, UV- screening agents, fragrances, matt-effect agents, and abrasive fillers or exfoliants, and mixtures thereof.

A composition suitable for the invention may advantageously comprise at least one additional active agent.

The expression "additional active agent" is intended to mean, in the context of the present invention, a compound which, by itself, i.e. not requiring the intervention of an external agent to activate it, has a biological activity which may in particular be:

- a depigmenting activity, and/or

- a photoprotective activity, and/or

- a barrier function-stimulating activity, and/or

- a moisturising or humectant activity, and/or

- a desquamating activity, and/or

- a soothing or anti-irritant activity, and/or

- an exfoliating activity, and/or

- a fibroblast proliferation-stimulating or keratinocyte proliferation-stimulating activity, and/or

- an activity for promoting the maturation of the horny envelope.

The additional active agent used in a composition suitable for the invention can represent from 0.0001% to 20%, preferably from 0.01% to 10% and even better still from 0.01 ) to 5% by weight relative to the total weight of the composition. Moreover, a composition suitable for the invention may advantageously comprise from 5% to 80% by weight and preferably from 35% to 75% by weight of water relative to the total weight of said composition.

A composition suitable for the invention may advantageously have a firm and compact feel when taken up. It may be thick on application and then become transformed, melt and release freshness.

Needless to say, those skilled in the art will take care to select this or these optional additional compound(s), and/or the amount thereof, such that the advantageous properties of the essential oil according to the invention are not, or are not substantially, adversely affected by the envisaged addition, and such that the properties of the compositions resulting therefrom are compatible with the preferred route of administration.

A composition that is suitable for the invention may advantageously comprise at least one fatty phase that is liquid at ambient temperature and atmospheric pressure.

As examples of oils that may be used in a composition that is suitable for the invention, mention may be made of:

- hydrocarbon-based oils of animal origin, such as perhydrosqualene;

- hydrocarbon-based oils of plant origin, such as liquid triglycerides of fatty acids containing from 4 to 10 carbon atoms, for instance heptanoic or octanoic acid triglycerides, or alternatively, for example, sunflower oil, maize oil, soya bean oil, marrow oil, grapeseed oil, sesame seed oil, hazelnut oil, apricot oil, macadamia oil, arara oil, castor oil, avocado oil, caprylic/capric acid triglycerides, for instance those sold by the company Stearineries Dubois or those sold under the names Miglyol 810, 812 and 818 by the company Dynamit Nobel, jojoba oil and shea butter oil;

- synthetic esters and ethers, in particular of fatty acids, for instance the oils of formulae R₁COOR₂ and R₁OR₂ in which Ri represents the residue of a fatty acid comprising from 8 to 29 carbon atoms, and R₂ represents a branched or unbranched hydrocarbon-based chain containing from 3 to 30 carbon atoms, for instance Purcellin oil, isononyl isononanoate, isopropyl myristate, 2-ethylhexyl palmitate, 2-octyldodecyl stearate, 2-octyldodecyl erucate, isostearyl isostearate; hydroxylated esters, such as isostearyl lactate, octylhydroxystearate, octyldodecyl hydroxystearate, diisostearyl malate, triisocetyl citrate, fatty alcohol heptanoates, octanoates and decanoates; polyol esters, such as propylene glycol dioctanoate, neopentyl glycol diheptanoate and diethylene glycol diisononanoate; and pentaerythritol esters, such as pentaerythrityl tetraisostearate;

- linear or branched hydrocarbons of inorganic or synthetic origin, such as volatile or non-volatile liquid paraffins, and derivatives thereof, isohexadecane, isododecane, petroleum jelly, polydecenes, and hydrogenated polyisobutene such as Parleam^® oil;

- associated natural or synthetic essential oils;

- fatty alcohols containing from 8 to 26 carbon atoms, such as cetyl alcohol, stearyl alcohol and a mixture thereof (cetylstearyl alcohol), octyldodecanol, 2-butyloctanol, 2-hexyldecanol, 2-undecylpentadecanol, oleyl alcohol and linoleyl alcohol;

- partially hydrocarbon-based and/or silicone-based fluoro oils, for instance those described in document JP-A-2 295 912;

- silicone oils, for instance volatile or non-volatile polymethylsiloxanes (PDMS) with a linear or cyclic silicone chain, which are liquid or pasty at ambient temperature, in particular cy clopoly dimethyl siloxanes (cyclomethicones) such as cyclohexasiloxane and cyclopentasiloxane; poly dimethyl siloxanes comprising alkyl, alkoxy or phenyl groups, which are pendent or at the end of a silicone chain, these groups containing from 2 to 24 carbon atoms; phenylsilicones, for instance phenyl trimethicones, phenyl dimethicones, phenyltrimethylsiloxydiphenylsiloxanes, diphenyl dimethicones, diphenylmethyldiphenyltrisiloxanes or 2-phenylethyl trimethylsiloxy silicates, and polymethylphenylsiloxanes, and

- mixtures thereof.

In the list of the abovementioned oils, the term "hydrocarbon-based oil" is intended to mean any oil predominantly comprising carbon and hydrogen atoms, and optionally ester, ether, fluoro, carboxylic acid and/or alcohol groups.

The other fatty substances that may be present in the oily phase are, for example, waxes and fatty acids comprising from 8 to 30 carbon atoms, for instance stearic acid, lauric acid, palmitic acid and oleic acid.

As waxes that may be used according to the invention, mention may be made of waxes of animal origin such as beeswax, spermaceti, lanolin wax and lanolin derivatives, plant waxes such as carnauba wax, candelilla wax, ouricury wax, Japan wax, cocoa butter, cork fibre wax or sugarcane wax, inorganic waxes, for example paraffin wax, petroleum jelly wax, lignite wax or microcrystalline waxes or ozokerites, synthetic waxes, among which are polyethylene waxes, polytetrafluoroethylene waxes and the waxes obtained by Fisher- Tropsch synthesis or alternatively silicone waxes, hydrogenated oils that are solid at 25°C, such as hydrogenated castor oil, hydrogenated jojoba oil, hydrogenated palm oil, hydrogenated tallow or hydrogenated coconut oil, and fatty esters that are solid at 25°C, for instance the C20-C40 alkyl stearate sold under the trade name Kester Wax K82H by the company Koster Keunen.

These fatty substances may be chosen in a varied manner by those skilled in the art so as to prepare a composition having the desired properties, for example in terms of consistency or texture.

The compositions suitable for the invention may comprise a volatile oil.

For the purposes of the invention, the term "volatile oil" is intended to mean an oil that is capable of evaporating on contact with keratin fibres in less than one hour, at ambient temperature and atmospheric pressure. The volatile organic solvent(s) and volatile oils of the invention are volatile organic solvents and cosmetic oils that are liquid at ambient temperature, with a non-zero vapour pressure at ambient temperature and atmospheric pressure, ranging in particular from 0.13 Pa to 40 000 Pa (10^"3 to 300 mmHg), in particular ranging from 1.3 Pa to 13 000 Pa (0.01 to 100 mmHg), and more particularly ranging from 1.3 Pa to 1300 Pa (0.01 to 10 mmHg).

Volatile oils that may be mentioned, inter alia, include linear or cyclic silicones containing from 2 to 6 silicon atoms, such as cyclohexasiloxane, dodecamethylpentasiloxane, decamethyltetrasiloxane, butyltrisiloxane and ethyltrisiloxane. It is also possible to use branched hydrocarbons, for instance isododecane, and also volatile perfluoroalkanes such as dodecafluoropentane and tetradecafluorohexane, sold under the names PF 5050^® and PF 5060^® by the company 3M, and perfluoromorpholine derivatives, such as 4-trifluoromethylperfluoromorpholine sold under the name PF 5052^® by the company 3M.

The amount of oily phase present in the compositions suitable for the invention may range, for example, from 0.01% to 50% by weight and preferably from 0.1% to 30% by weight relative to the total weight of the composition.

A composition suitable for the invention may advantageously be in the form of an emulsion, obtained in particular by dispersing an aqueous phase in a fatty phase (W/O) or a fatty phase in an aqueous phase (O/W), of liquid or semi-liquid consistency of the milk type, or of soft, semi-solid or solid consistency of the cream or gel type, or alternatively a multiple emulsion (W/O/W or 0/W/O). These compositions are prepared according to the usual methods.

A composition of this type may be in the form of a face and/or body care product, and may be conditioned, for example, in the form of cream in a jar or of fluid in a tube or a pump-action bottle.

The emulsions suitable for the invention generally comprise at least one emulsifier chosen from amphoteric, anionic, cationic and non-ionic emulsifiers, used alone or as a mixture.

Advantageously, the emulsifiers are appropriately chosen according to the emulsion to be obtained (W/O or O/W). The emulsifiers are generally present in the composition in a proportion that may range from 0.3% to 30% by weight and preferably from 0.5% to 20% by weight relative to the total weight of the composition.

Examples of emulsifiers that may be mentioned for the O/W emulsions include non-ionic surfactants, and in particular esters of polyols and of fatty acids with a saturated or unsaturated chain containing, for example, from 8 to 24 carbon atoms and better still from 12 to 22 carbon atoms, and the oxyalkylenated derivatives thereof, i.e. derivatives containing oxyethylenated and/or oxypropylenated units, such as the glyceryl esters of C₈- C₂4 fatty acids, and the oxyalkylenated derivatives thereof; the polyethylene glycol esters of C₈-C₂4 fatty acids, and the oxyalkylenated derivatives thereof; the sorbitol esters of C₈- C₂4 fatty acids, and the oxyalkylenated derivatives thereof; the sugar (sucrose, glucose or alkylglucose) esters of C₈-C₂4 fatty acids, and the oxyalkylenated derivatives thereof; fatty alcohol ethers; the sugar ethers of C₈-C₂4 fatty alcohols, and mixtures thereof.

A composition suitable for the invention may also comprise at least one silicone elastomer, for instance the products sold under the name KSG by the company Shin-Etsu, under the name Trefil, BY29 or EPSX by the company Dow Corning, or under the name Gransil by the company Grant Industries.

A composition suitable for the invention may also comprise at least one colorant chosen, for example, from pigments, nacres, dyes and materials with an effect, and mixtures thereof. These colorants may be present in a content ranging from 0.01% to 50% by weight and preferably from 0.01% to 30% by weight relative to the total weight of the composition.

A composition suitable for the invention may also comprise at least one filler, in particular in a content ranging from 0.01% to 50% by weight and preferably ranging from 0.01 ) to 30% by weight relative to the total weight of the composition.

These fillers may be inorganic or organic and of any shape, platelet-shaped, spherical or oblong, irrespective of the crystallographic form (for example lamellar, cubic, hexagonal, orthorhombic or amorphous).

Mention may be made of silica, talc, mica, kaolin, lauroyllysine, starch, boron nitride, PTFE powders, PMMA powders, methyl silsesquioxane resin powders (for instance Tospearl 145A from GE Silicone), hollow silicone resin hemispherical particles (for instance LK 500, NLK 506 and NLK 510 from Takemoto Oil and Fat), barium sulfate, precipitated calcium carbonate, magnesium carbonate, magnesium hydrogen carbonate, hydroxyapatite, glass or ceramic microcapsules, and metal soaps derived from organic carboxylic acids containing from 8 to 22 carbon atoms and preferably from 12 to 18 carbon atoms, for example zinc stearate, magnesium stearate, lithium stearate, zinc laurate or magnesium myri state.

In the case of oral administration, the composition may be in the form of tablets, gel capsules, sugar-coated tablets, syrups, suspensions, solutions, powders, granules, emulsions, suspensions of microspheres, nanospheres or lipid or polymeric vesicles allowing controlled release. Preferably, the composition is in the form of a food supplement.

A composition that is suitable for the invention may be manufactured via any known process generally used in the cosmetic field.

The cosmetic treatment process of the invention is advantageously performed by topically administering a composition comprising an essential oil of Laserpitium siler L. in accordance with the invention.

The topical administration consists of the external application to the skin of cosmetic compositions according to the usual technique for using these compositions. The non-therapeutic cosmetic treatment process according to the present invention is characterized in that said essential oil is obtained from the leaves, umbels, seed-bearing umbels and/or fruit seeds of Laserpitium siler L..

According to this first particular embodiment, said process is characterized in that said essential oil of Laserpitium siler L. comprises an amount of limonene ranging from 40% to 80% by weight and preferably ranging from 50% to 70% by weight relative to the total weight of said essential oil, an amount of perillaldehyde ranging from 15% to 40% by weight and preferably ranging from 20% to 35% by weight relative to the total weight of said essential oil, and an amount of chamazulene of less than or equal to 10% and preferably less than or equal to 5% by weight relative to the total weight of said essential oil.

According to this second embodiment, the essential oil of Laserpitium siler L. according to the invention comprises at least 40%, preferably at least 50% by weight and better still at least 65% by weight of monoterpenes chosen from limonene, myrcene, sabinene, γ-terpinene, para-cymene and a-pinene, and at least 5% by weight and preferably at least 15% by weight of sesquiterpenes chosen from chamazulene, germacrene D and trans-P-caryophyllene.

By way of illustration, the cosmetic process according to the invention may be performed by topical application, for example daily, of the essential oil of Laserpitium siler L. in accordance with the invention, which may, for example, be formulated in the form of creams, gels, sera, lotions, emulsions, makeup-removing milks or aftersun compositions.

The process according to the invention may comprise a single application.

According to another embodiment, the application is repeated, for example 2 to 3 times daily for one day or more and generally for an extended period of at least 4 weeks, or even 4 to 15 weeks with, where appropriate, one or more periods of stoppage. Furthermore, treatment combinations optionally with oral or topical forms may be envisaged, in order to complement or to reinforce the activity of the essential oil of Laserpitium siler L. as defined by the invention.

Thus, a topical treatment with a composition containing an essential oil of Laserpitium siler L. in accordance with the invention, combined with an orally or topically administered composition optionally containing another essential oil, could be imagined.

The ingredients are mixed, before being formed, in the order and under conditions that are easily determined by those skilled in the art.

According to one particular embodiment of the invention, other agents intended to make the appearance and/or the texture of the skin more attractive may also be added to a composition suitable for the invention.

Description of the figure

Figure 1: Graph illustrating the inhibitory activity on melanin synthesis of the essential oil of Laser siler suitable for the invention on cocultures of normal human melanocytes and keratinocytes.

Throughout the description, including the claims, the term "comprising a" should be understood as being synonymous with "comprising at least one", unless otherwise specified.

The terms "between... and..." and "ranging from... to..." should be understood as being inclusive of the limits, unless otherwise specified.

The examples and figures that follow are presented as non-limiting illustrations of the invention. The compounds are, depending on the case, cited as the chemical names or as the CTFA (International Cosmetic Ingredient Dictionary and Handbook) names.

Examples

Example 1: Production of an essential oil according to the invention

0.1 kg of seed-bearing umbels of freshly harvested Laserpitium siler L. fruit is distilled, dried and flattened.

This distillation is performed for 180 minutes according to the steam distillation (or hydrodistillation) technique in a "4-litre Clevenger" apparatus, i.e. apparatus based on the same principle as that detailed in the European Pharmacopoeia (PH. Eur. 4th Ed 2.8.12).

8 g of an essential oil according to the invention are thus obtained. Chemical analysis of the composition of the essential oil thus obtained is performed by gas chromatographic GC analysis.

The results indicate that an essential oil of Laserpitium siler L. in accordance with the invention comprises as main compounds limonene (68.95%), perillaldehyde (23.79%) and chamazulene (1.49%).

Example 2: Production of an essential oil according to the invention

0.3 kg of freshly harvested Laserpitium siler L. leaves are "fresh"-distilled without pretreatment.

This distillation is performed for 180 minutes according to the steam distillation technique in a 4-litre Clevenger apparatus, i.e. apparatus based on the same principle as that detailed in the European Pharmacopoeia (PH. Eur. 4th Ed 2.8.12).

0.7 g of an essential oil according to the invention are thus obtained.

Chemical analysis of the composition of the essential oil thus obtained is performed by gas chromatographic GC analysis.

The results indicate that an essential oil of Laserpitium siler L. in accordance with the invention comprises as main compounds limonene (29.62%), myrcene (4.15%), sabinene (19.96%), γ-terpinene (2.12%), para-cymene (0.77%), a-pinene (12.17%), germacrene D (10.15%), chamazulene (5.29%) and trans-P-caryophyllene (2.59%).

Example 3: Demonstration of the activity on melanogenesis according to

Example 1

Protocol

Unless specifically mentioned, the percentages indicated in this text are weight percentages. A biological test demonstrated the depigmenting activity of the essential oil of Laserpitium siler L..

The modulatory effect on melanogenesis of the essential oil was measured according to the method described in the patent FR-A-273 4825, and also in the article by R. Schmidt, P. Krien and M. Regnier, Anal. Biochem., 235(2), 113-18, 1996. This test is carried out on a coculture of keratinocytes and melanocytes.

For each essential oil tested, the inhibitory activity on melanin synthesis, by estimating the ratio of the incorporation of thiouracil to the incorporation of leucine, related to 100% of the control (the control corresponds to the test carried out without the essential oil of Laserpitium siler L. to be tested), was determined. The IC50 values (concentration for which 50% of the melanin synthesis is inhibited) were determined.

To evaluate the level of melanin synthesis, the keratinocyte and melanocyte cells are placed beforehand in a culture medium comprising ¹⁴C thiouracil, which is a melanin precursor. The medium is changed every day. The cells are then lysed using a solution comprising the proteinase K® sold by the company Boehringer. The resulting lysate is then filtered on DEAE-cellulose membrane filters (the anion exchanger of the filters corresponds to resins comprising diethylaminoethyl groups). 18 hours before the quantitative determination, H leucine is added to the culture medium in order to evaluate the protein synthesis. Before filtration of the lysate obtained, a sample is taken in order to evaluate the amount of protein synthesized, based on the incorporation of the H leucine. The radioactivity of the filters is then counted in a liquid scintillation counter.

Results

Melanin synthesis

It is noted, according to Figure 1, that the plateau is reached at approximately -40%, from a 0.05% concentration of the essential oil of Laser siler L.

This indicates that the essential oil of Laser siler is 40% more depigmenting than the control (called placebo) devoid of essential oil of Laser siler, for a concentration of 0.05%.

This test also demonstrates that the plateau of effectiveness in terms of depigmenting activity is reached with a composition comprising essential oil of Laser siler L. from the concentration of 0.05% by weight in the coculture model. The test for inhibitory activity on melanin synthesis was also carried out with lucinol (2-butylbenzene-l,3-diol), which is a known depigmenting compound.

The results obtained for the essential oil of Laser siler L. suitable for the invention, and for lucinol, are reproduced in the Table 1 which follows.

Table 1

Regarding the IC50 for lucinol (positive reference), a value of 1.8 μΜ corresponds to a value of approximately 0.3 mg/1, i.e. 0.00003%).

Example 4: Compositions

CARE CREAM, Oil-in-water emulsion

When applied to the skin of the face and of the body, this cream makes it possible to lighten the skin.

FACE CREAM

When applied to the face, the present cream makes it possible to improve the homogeneity of the complexion and to revive the radiance of the complexion.

Claims

1. Cosmetic use of the essential oil of Laserpitium siler L. as an active agent for depigmenting, lightening and/or bleaching keratin materials, in particular the skin of the face and/or of the body, and/or for preventing, reducing and/or treating a modification of the skin complexion or of the colour of the semi-mucous membranes.

2. Cosmetic use according to Claim 1, for treating at least one unattractive benign pigmentation disorder chosen from hyperpigmentations, actinic lentigo, lentigines, freckles, chloasma, melasmas, idiopathic melasmas occurring during pregnancy or during oestro-progestogen contraception, pigmentary sequelae of acne, post-inflammatory pigmentation, phytodermatitis, pigmentation associated with the plant poison ivy, and benign dyschromias of the face.

3. Cosmetic use according to Claim 1, for making the complexion homogeneous and/or reviving the radiance of the complexion.

4. Cosmetic use according to any one of Claims 1 to 3, characterized in that said essential oil of Laserpitium siler L. is used in a cosmetic composition in a content ranging from 0.0001% to 10%> by weight, preferably from 0.001%) to 1%> by weight, most preferentially from 0.01%> to 0.5%> by weight and even better still from 0.01%> to 0.1%> by weight relative to the total weight of the cosmetic composition.

5. Cosmetic use according to any one of Claims 1 to 4, characterized in that said essential oil is obtained from the leaves and/or from the umbels and/or from the seed- bearing umbels and/or from the fruit seeds of Laserpitium siler L..

6. Cosmetic use according to Claim 5, characterized in that said essential oil is obtained from the umbels.

7. Cosmetic use according to Claim 5 or Claim 6, characterized in that said essential oil is obtained from the seed-bearing umbels.

8. Cosmetic use according to Claim 5, characterized in that said essential oil is obtained from the leaves, preferably by means of a steam distillation process.

9. Cosmetic use according to any one of Claims 1 to 7, characterized in that said essential oil of Laserpitium siler L. comprises an amount of limonene ranging from 40%) to 80%) by weight and preferably ranging from 50%> to 70%> by weight relative to the total weight of said essential oil, an amount of perillaldehyde ranging from 15%> to 40%> by weight and preferably ranging from 20% to 35% by weight relative to the total weight of said essential oil, and an amount of chamazulene of less than or equal to 10% and preferably less than or equal to 5% by weight relative to the total weight of said essential oil.

10. Cosmetic use according to any one of Claims 1 to 5 and 8, characterized in that said essential oil of Laserpitium siler L. comprises at least 40%, preferably at least 50%) by weight and better still at least 65% by weight of monoterpenes chosen from limonene, myrcene, sabinene, γ-terpinene, para-cymene and a-pinene, and at least 5% by weight and preferably at least 15% by weight of sesquiterpenes chosen from chamazulene, germacrene D and trans-P-caryophyllene.

11. Non-therapeutic cosmetic treatment process for depigmenting, lightening and/or bleaching keratin materials, in particular the skin of the face and/or the body, and/or for preventing, reducing and/or treating a modification of the skin complexion or of the colour of the semi-mucous membranes, comprising at least one step consisting in applying, to the skin of the face and/or the body, at least one composition comprising essential oil of Laserpitium siler L..

12. Process according to Claim 1 1, characterized in that said essential oil is as defined in one of Claims 4 to 10.