EP2364136A1

EP2364136A1 - Cosmetic use of skin cell autophagy activators

Info

Publication number: EP2364136A1
Application number: EP09801742A
Authority: EP
Inventors: Jean Paufique
Original assignee: Societe Industrielle Limousine dApplication Biologique SA SILAB
Current assignee: Societe Industrielle Limousine dApplication Biologique SA SILAB
Priority date: 2008-12-05
Filing date: 2009-12-04
Publication date: 2011-09-14
Also published as: FR2939316A1; WO2010063977A1; US20120225092A1; FR2939316B1; US20110243983A1; US8512764B2; US9138400B2

Abstract

The invention relates to the use, in a cosmetic composition, of an effective amount of at least one skin cell autophagy activator as a cosmetic active principle. The invention also relates to cosmetic compositions containing at least one skin cell autophagy activator as a cosmetic active principle 5 and to a cosmetic method for detoxifying the skin and/or for preventing or fighting skin aging.

Description

COSMETIC USE OF ACTIVATORS OF THE AUTOPHAGIA OF SKIN CELLS

The present invention relates to the use in a cosmetic composition of an activator of autophagy of skin cells as a cosmetic active ingredient.

The invention also relates to cosmetic compositions comprising at least one autophagic activator for skin cells as a cosmetic active ingredient and a cosmetic process for detoxifying the skin and / or for preventing or combating cutaneous aging, comprising: topical application to the skin of such compositions. The skin, organ of contact with the environment, is constantly subjected to external and internal aggression, which threatens its balance and modifies its appearance.

It is known, for example, that excessive exposure to ultraviolet (UV) radiation results in various cutaneous manifestations, such as actinic erythema, solar elastosis or the premature appearance of the effects of skin aging: the skin becomes loose, deeply wrinkled, rough, dry, strewn with hypopigmented or hyperpigmented spots and dilated vessels. These manifestations, which reflect profound structural changes in the skin tissue, are unsightly and unsightly and many people tend to want to fade them. This is why the objective of the present invention is to provide an effective means for protecting the skin against the aggressions likely to alter its proper functioning and its appearance, and to fight against the resulting manifestations. To answer this, the present invention proposes using as a cosmetic active ingredient in a cosmetic composition at least one activator of the autophagy of skin cells, in particular keratinocytes and fibroblasts. In fact, the use of at least one autophagic activator for cutaneous cells makes it possible to fight against the accumulation of deleterious molecules in the cutaneous cells produced in the event of stress and thus to fight against the resulting manifestations. In particular, the invention relates to the use in a cosmetic composition of at least one autophagic activator of skin cells, in particular keratinocytes and / or fibroblasts, as an active ingredient, for detoxifying skin cells. , fight against aging of the skin, restructure the skin, moisturize and protect the stratum corneum, increase cell renewal, protect cells from the harmful effects of UVA and UVB radiation and limit inflammation phenomena.

Preferably, the invention relates to the use in a cosmetic composition of at least one activator of autophagy of skin cells, as an active ingredient for detoxifying skin cells and / or to fight against skin aging. Advantageously, by increasing the autophagy mechanism in cutaneous cells, the use according to the invention makes it possible to increase the elimination of damaged molecules, to detoxify the skin and to limit skin aging. Indeed, under certain conditions, especially with age and overexposure to the sun, the skin cells are no longer able to evacuate the molecules damaged by radiation and various stresses. The cells are engorged by these damaged molecules and by free radicals. The cosmetic use of autophagic activators of cutaneous cells according to the invention It helps to limit this cellular engorgement and to rid the cells of deleterious and useless elements that hinder its optimal functioning by accumulating.

The invention also relates to a cosmetic composition for topical application to the skin comprising, in a physiologically acceptable medium, an effective amount of at least one autophagic activator for cutaneous cells chosen from active principles derived from Lithothamnium calcareum, Melilotus off icinalis. , Citrus limonum, Candida saitoana, Lens culinaris, Averrhoa carambola, Momordica charantia, Yarrowia lipolytica and at least one cosmetic adjuvant. Preferentially, the autophagic activator of the cutaneous cells is present in an amount of between 0.1 and 15% by weight relative to the total weight of the composition.

Finally, the invention also relates to a cosmetic process for detoxifying the skin and / or for preventing or combating cutaneous aging, comprising the topical application to the skin of a composition comprising at least one activator of the autophagy of the skin. skin cells. The invention is now described in detail.

The present invention therefore relates to the use in a cosmetic composition of an activator of autophagy, as a cosmetic active ingredient. Autophagy is a mechanism for recycling and detoxifying constituents and cellular organelles. In particular, autophagy can regulate, repair and eliminate long-lived proteins in cells, thus ensuring control during the differentiation and aging of human skin. On the cellular level, the mechanism of autophagy, comprises four stages: the initiation, the formation of an initial vacuole, called autophagosome, which sequesters the cytoplasmic material, the maturation of the autophagosome in vacuole degraded and fusion with the lysosome, until the degradation of the sequestered material.

According to a first aspect, a skin cell autophagic activator useful according to the invention may be an active ingredient having a stimulating activity for the expression of MAP-LC3 (microtubule-associated membrane protein) microtubule-associated membrane proteins. and / or ATG5-12 ("Autophagy-related genes", autophagy genes) of skin cells. Indeed, the formation of the autophagosome, an essential step in the mechanism of autophagy, involves two systems of conjugation: the ATG5-12 complex and MAP-LC3.

The first step of autophagy is the formation of a multimembrane structure, called phagophore, whose origin remains unknown. This structure extends to form the autophagosome that sequesters the cytoplasmic material. The autophagosome fuses with the lysosome and its contents are then degraded by the lysosomal enzymes. During the formation of the autophagosome, ATG proteins are recruited from the cytoplasm and transitably associate with the autophagosomal membrane. This process involves mainly three protein complexes: the class III PI (3) K associated with the Bécline 1 protein and two conjugation systems. The early event in the induction of autophagosome formation is the production of phosphatidyl inositol 3-phosphate by the Bécline 1-PI (3) K class III complex which allows the recruitment of the first ATG12-ATG5 conjugation system , also noted ATG5-12. The latter, in turn, allows the conjugation of phosphatidyl ethanolamine (PE) to the MAP-LC3 protein to form the MAP-LC3-PE conjugate, which is then recruited to the autophagosomal membrane. ATG genes are therefore involved in the formation of the autophagosome and

YATG5-12 is precursor to MAP-LC3 and phosphatidyl ethanolamine (PE) conjugation.

Map-LC3 are 15kDa proteins found in mammals. They are involved in the formation of autophagosome membranes. There are two forms: a cystolic form the LC3-I and a form bound to the LC3-II membrane.

The Map-LC3 are first cleaved, directly after their synthesis, at their C-terminal part to give the LC3-I cystolic form. During autophagy, LC3-I is converted to LC3-II, and proteins associate with autophagic vacuoles.

Thus, the use of an active ingredient exhibiting an activity stimulating the expression of MAP-LC3 and / or AT65-12 of the cells of the skin makes it possible to stimulate the formation of the autophagosome and therefore to stimulate the formation of the autophagosome. autophagy of the skin cells.

According to a second aspect, an activator of skin cell autophagy useful according to the invention may be an active ingredient inhibiting the activation of phosphorylated mTOR.

MTOR ("mammalian target of rapamycin" or mammalian rapamycin target) is a molecule involved in the initiation of autophagosome formation and acts as a sensor for ATP and regulating amino acids. the balance between nutrient availability and cell growth.

When the amount of nutrients is sufficient, mTOR is phosphorylated on the 2448 seine and transmits a positive signal activating cell growth and inhibiting autophagy. In the opposite case, that is to say in conditions of nutritional deprivation or starvation, this phosphorylation disappears in favor of a phosphorylation of threonine 2446, which allows the lifting of the inhibition of autophagy. The mechanism of autophagy is therefore initiated when there is dephosphorylation of mTOR on serine 2448.

Thus, the cosmetic use of an active inhibitor of mTOR activity in skin cells makes it possible to promote the initiation of autophagy, to mobilize the formation of autophagosomes and thus to stimulate autophagy of the cells of the skin. the skin. According to a last aspect, a stimulator of the autophagic activity of cutaneous cells useful according to the invention may be an active ingredient having a stimulating activity for the expression of p53 protein, AMPK and / or DRAM. The p53 protein is a major stress protein, capable in particular of: activating DRAM (Damage Regulated Autophagy Modulator) protein, a protein directly involved in the initiation of the mechanism of autophagy, and

- To inhibit mTOR through the activation of a protein kinase, AMPK. The activation of DRAM and / or AMPK, either directly or through p53, thus stimulates autophagy.

Thus, the cosmetic use of an active ingredient having an activity stimulating the expression of the phosphorylated p53 protein, DRAM and / or AMPK of the skin cells, makes it possible to promote the initiation of autophagy , to mobilize the formation of autophagosomes and thus to stimulate the autophagy of skin cells.

The cellular consequence of an activation of the mechanism of autophagy by an active principle having a stimulating activity of the expression of MAP-LC3, ATG5-12, phosphorylated p53 protein, DRAM and / or AMPK and or having a phosphorylated mTOR inhibitory activity, is a better detoxification of cells, that is to say a decrease in reactive oxygen species and degenerate macromolecules blocked in cutaneous cells. Preferably, the stimulator of the autophagic activity of cutaneous cells useful according to the invention is an active ingredient derived from at least one plant, an alga or a yeast.

Preferably, the autophagy activator is an active ingredient derived from at least one algae of the genus Lithothamnium calcareum, or from a plant chosen from Melilotus officinalis, Citrus limonum, Lens culinaris, Averrhoa carambola, Momordica charantia or a yeast selected from Candida saitoana and Yarrowia lipolytica.

According to one aspect of the invention, the autophagic activator of cutaneous cells is capable of being selected by a test carried out on cutaneous cell cultures comprising the following steps: - culture of cutaneous cells, keratinocytes or fibroblasts, in a suitable culture medium,

- removal of the culture medium and replacement with a culture medium comprising a stressing agent inducing nutrient stress and / or oxidative if - adding an active ingredient from plant, seaweed or yeast to be tested in the medium of culture,

removal of the oxidizing agent and replacement of the culture medium with a culture medium comprising the active principle, and

analysis of the expression of MAP-LC3, ATG5-12, phosphorylated mTOR, phosphorylated p53 protein, expression of the protein

DRAM and / or AMPK by said cells, and comparison of the results with those obtained on cultures of cutaneous cells not treated with the extract to be tested. If there is an increase in the expression of MAP-LC3, of ATG5-l2 phosphorylated protein p53, DRAM protein and / or AMPK I ^1, and / or a decrease in phosphorylated mTOR, then the principle tested active can be used in a cosmetic composition as an activator of autophagy of skin cells.

To illustrate the invention, several active ingredients have been tested to study their ability to increase the autophagy of cutaneous cells. First of all it was verified that the induction of a stress at the level of the cells of the skin led to an increase of autophagy. The autophagy level of young and old cells subjected to the same oxidative and nutritive stress was then compared.

Finally active ingredients have been selected by the implementation of the test method according to the invention.

1 / Visualization of the autophaqiβ of cutaneous cells after a nutritive stress

The protocol consists in submitting normal human HaCaT keratinocytes or keratinocytes to nutrient stress, that is to say to an absence of growth factors, for a certain time and to evaluate the expression of several markers of autophagy during cellular recovery.

The protocol is as follows:

- skin cell cultures for 24 hours in complete culture medium (with growth factors)

withdrawal of the complete culture medium and replacement with a non-nutritive culture medium (without growth factor). The cells are cultured for several times (from 0.5h to 24h) in a state of nutritional stress, after these times of cultures in a state of nutritive stress, withdrawal of the non-nutritive culture medium and replacement with complete culture medium, and finally evaluation of the autophagy state of the cutaneous cells by evaluation of the expression of MAP-LC3 , AT65-12 complex, phosphorylated mTOR, phosphorylated p53, DRAM and phosphorylated AMPK after cell recovery.

1.1 / Evaluation of the expression of MAP-LC3 after nutritional stress It is possible to evaluate the autophagy of cutaneous cells by visualizing the expression of the MAP-LC3 protein by immunofluorescent labeling. The expression of MAP-LC3 was evaluated on skin cell cultures of HaCaT lines and on normal human keratinocytes after different contact times of nutrient stress. The immunolabeling results being qualitative, several levels of expression of MAP-LC3 were defined:

- very weak immunoreactivity detection

- weak immunoreactivity detection ±

- average immunoreactivity detection +

- strong immunoreactivity detection ++ The results obtained are presented in the following table

During the cultivation of HaCaT keratinocytes in a state of nutritional stress, the net appearance of a MAP-LC3 punctiform marking in the cytoplasm of the cells is observed. This labeling reflects the formation of autophagosomes in keratinocytes subjected to nutrient stress. This marking is observable from 2 hours of starvation and reaches a maximum after 4 hours of starvation.

These conditions of nutritive stress thus make it possible to induce the formation of autophagosomes and consequently an autophagy, visualized by the expression of MAP-LC3.

1.2 / Assessment of ATG5-12 complex expression after nutrient stress

It is also possible to evaluate the autophagy of cutaneous cells by visualizing the expression of the ATG5-12 complex by immunofluorescence staining. Evaluation of AT65-12 complex expression was performed on skin cell cultures of HaCaT lines and on normal human keratinocytes after different culture times under nutrient stress. Immunolabeling results being qualitative, several ATG5-12 expression levels were defined: - very weak immunoreactivity detection

- weak immunoreactivity detection ±

- average immunoreactivity detection +

- strong immunoreactivity detection ++

very strong detection of immunoreactivity +++ The results obtained are presented in the following table:

During the cultivation of HaCaT keratinocytes under nutrient stress, the appearance of a punctiform AT65-12 marking at the level of the cytoplasm of the cells is observed. This labeling reflects the formation of autophagosomes in keratinocytes subjected to nutrient stress.

This marking is observable from 1 hour and up to 3 hours of starvation.

The conditions of nutritive stress thus make it possible to induce a phenomenon of the autophagic type, visualized by the expression ATG5-12.

1.3 / Evaluation of phosphorylated mTOR expression after nutrient stress

It is also possible to evaluate the autophagy of cutaneous cells by visualizing the expression of mTOR phosphorylated by Western Blott.

The evaluation of phosphorylated mTOR expression was evaluated on skin cell cultures of HaCaT lines and on normal human keratinocytes after different culture times under nutrient stress. The expression of phosphorylated mTOR is presented in the table below in percentage relative to the control (without nutritional stress).

This experiment showed a clear decrease of the phosphorylated mTOR protein visible as early as 8 hours of deprivation, in cutaneous skin cell cultures subjected to starvation.

When the phosphorylated mTOR protein decreases, inhibition of autophagy is lifted.

The conditions of nutritive stress thus make it possible to induce autophagy on cutaneous cell cultures, visualized by the decrease in the expression of phosphorylated mTOR.

1.4 / Evaluation of phosphorylated p53 expression after nutritional stress It is also possible to evaluate the autophagy of cutaneous cells by visualizing the expression of the p53 protein phosphorylated by Western Blott.

The evaluation of the expression of the phosphorylated p53 protein was evaluated on skin cell cultures of HaCaT lines and on normal human keratinocytes after different culture times in a state of nutritional stress. The expression of phosphorylated p53 is presented in the table below in percentage relative to the control (without nutritional stress).

This experiment showed a clear increase in the expression of the phosphorylated p53 protein visible as early as 1 hour, in starved cell cultures.

The conditions of nutritive stress thus make it possible to induce an autophagic type phenomenon on cutaneous cell cultures, visualized by the increase in the expression of the phosphorylated p53 protein.

1.5 / Evaluation of DRAM protein expression after nutrient stress

It is also possible to evaluate the autophagy of cutaneous cells by visualizing the expression of the DRAM protein, by Western Blott, on skin cell cultures of HaCaT lines and on normal human keratinocytes after different times of culture in a state of nutritional stress. The expression of DRAM is presented in the table below in percentage relative to the control (without nutritional stress).

This experiment showed a marked increase in the expression of the DRAM protein after 0.5 hour of culture in a state of nutritional stress. The expression of the DRAM protein becomes maximal after 1.5 hours of culture in a state of nutritional stress. This coincides with the kinetics of expression of the p53 protein which reaches its maximum after one hour of nutrient stress.

The conditions of nutritive stress thus make it possible to induce an autophagic type phenomenon on skin cell cultures, visualized by the increase of the expression of the DRAM protein.

1.6 / Evaluation of the Expression of the Phosphorylated AMPK Protein After Nutrient Stress

It is also possible to evaluate the autophagy of cutaneous cells by visualizing the expression of the phosphorylated AMPK protein, by Western Blott, on skin cell cultures of HaCaT lines and on normal human keratinocytes after different culture times in state. of nutritive stress. The expression of DRAM is presented in the table below in percentage relative to the control (without nutritional stress).

This experiment has shown that the expression of phosphorylated AMPK is increased as early as 0.5 hour of culture in a state of nutritional stress and is maximal at 1.5 hours. This coincides with the kinetics of expression of the p53 protein that peaks after one hour of nutrient stress. Nutrient stress conditions thus make it possible to induce a phenomenon of α-trophophobic type on cutaneous cell cultures, visualized by the increase in the expression of the phosphorylated AMPK protein. These studies have thus made it possible to show that the autophagy mechanism can be indifferently visualized on cutaneous skin cell cultures stressed by the evaluation of the expression of various proteins such as MAP-LC3, the AT65-12 complex, of phosphorylated mTOR, the phosphorylated p53 protein, the DRAM protein or the phosphorylated AMPK protein.

2 / Visualization of autophaqiβ of cutaneous cells after nutritive and oxidative stress

Visualization of autophagy is possible, as in the case of nutritional stress, by the evaluation of different proteins such as MAP-LC3, the ATG5-12 complex, the phosphorylated mTOR protein, the phosphorylated p53 protein, the DRAM protein or the phosphorylated AMPK protein. In this experiment, autophagic expression of cutaneous cells was investigated by analyzing the expression of MAP-LC3, phosphorylated p53 protein and DRAM protein in stressed skin cell cultures. The operating protocol is as follows: - cell cultures for 24 hours in complete culture medium

withdrawal of the culture medium and replacement with non-nutrient culture medium containing the oxidizing agent H ₂ O ₂ for 3 h (different doses of H ₂ O ₂ - 125 μM and / or 250 μM - were tested).

removal of the oxidizing agent and the non-nutritive culture medium, replacement with complete culture medium without oxidant.

Evaluation of the expression of MAP-LC3, of the phosphorylated p53 protein or of the DRAM protein after cellular recovery. Several times of recovery were chosen (0.5 hours, 1 hour, 1.5 hours or 2 hours of recovery).

2.1 / Evaluation of MAP-LC3 expression after nutrient stress and oxidized if

It is possible to evaluate the autophagy of stressed skin cells by visualizing the expression of the MAP-LC3 protein by immunofluorescent staining.

The evaluation of MAP-LC3 expression was analyzed under these moderate stress conditions (125 μM and 250 μM of hydrogen peroxide HzOz) on HaCaT keratinocyte cultures and on normal human keratinocytes. The immunolabeling results being qualitative, several levels of AT65-12 expression were defined:

- very weak immunoreactivity detection

- weak immunoreactivity detection ±

- average immunoreactivity detection +

- strong immunoreactivity detection ++

- very strong detection of immunoreactivity +++

The results obtained are presented in the following table:

For the 125 μM dose of oxidative stress, we observe the punctiform marking of

MAP-LC3 at the level of the cytoplasm of the cells from 0.5 hour of recovery which becomes maximum after 1.5 hours, then decreases from 2 hours of recovery.

For the dose of 250 μM, it is found that this marking appears from 0.5 hour, reaches a maximum at 1 hour and weakens after 1.5 hours of recovery.

The conditions of nutritive and oxidative stress thus make it possible to induce a phenomenon of the autophagic type, visualized by the increase of the expression of MAP-LC3 in the cutaneous cells.

2.3 / Evaluation of the expression of the phosphorylated p53 protein after nutritive and oxidative stress

It is also possible to evaluate the autophagy of stressed skin cells by visualizing the expression of the phosphorylated p53 protein by Western Blott. The evaluation of the expression of the phosphorylated p53 protein was therefore analyzed under these conditions of moderate stress with 125 μM of WzOz, on HaCaT keratinocyte cultures and on normal human keratinocytes. The expression of phosphorylated p53 is presented in the following table as a percentage relative to the control (without stress).

For the 125 μM dose of nutritive and oxidative stress, it is observed that the labeling of the phosphorylated p53 protein is at its maximum after 0.5 hour of recovery, then gradually decreases. The oxidative stress conditions thus make it possible to induce a phenomenon of the α-trophophobic type, visualized by the increase in the expression of the phosphorylated p53 protein.

2.4 / Evaluation of the expression of the DRAM protein after nutrient stress and oxidized if

It is also possible to evaluate the autophagy of stressed skin cells by visualizing the expression of the DRAM protein by Western Blott. The evaluation of DRAM expression was therefore analyzed under these conditions of moderate stress with 125 μM of HzO ₂ , on HaCaT keratinocyte cultures and on normal human keratinocytes. The expression of DRAM is presented in the following table in percentage relative to the control (without stress).

Nutrient and oxidative stress on skin cell cultures is found to increase the expression of DRAM protein.

For the 125 μM dose of oxidative stress, it is observed that the labeling of the DRAM protein is at its maximum after 1.5 hours of recovery, then decreases from 2 hours. The conditions of nutritive and oxidative stress thus make it possible to induce a phenomenon of the autophagic type.

These studies have thus shown that the autophagy mechanism can be visualized on skin cell cultures stressed by the evaluation of the expression of different proteins such as MAP-LC3, the phosphorylated p53 protein or the DRAM protein.

3 / Comparison of autophaqiβ in young and old cells This study aims to compare the autophagy level of young (aged 26 years old) and elderly (middle aged 70 years old) cells. subjected to the same oxidative and nutritive stress.

Evaluation of the level of autophagy was considered by the analysis of MAP-LC3 protein expression by Western Blott. The protocol set up is as follows:

- Cell cultures say young or old for 24 hours in complete culture medium.

- Removal of the complete culture medium, asec replacement of the non-nutrient culture medium containing the oxidizing agent H2O2 for 3 hours at different doses

- removal of the oxidizing agent, replacement with complete culture medium without oxidant,

Evaluation of the expression of MAP-LC3 after cellular recovery.

The results are described in the table below in percentage relative to the control (without stress).

Under the conditions of this study, so-called young skin cells show an increase in MAP-LC3 expression when subjected to moderate oxidative stress (125, 250, see 400 μM). When subjected to significant oxidative stress (600 and 1000 μm), they are placed in apoptosis. The so-called aged skin cells do not exhibit the same increase in MAP-LC3 expression when subjected to the same moderate oxidative stress.

This difference in autophagy of older cells compared to young cells is significant. This study shows that older cells are no longer able to protect themselves and detoxify during moderate nutrient and oxidative stress.

4 / Screening of active principles increasing the autophaqiβ of cutaneous cells

The screening is carried out according to the protocol of nutritive and oxidative stress presented in point 2.1, starting from active ingredients derived from plants, algae or yeasts. The evaluation of the effect of active principles on cutaneous skin autophagy was performed by analyzing the expression of the MAP-LC3 protein in skin cell cultures subjected to nutritive and oxidative stress. The test protocol is as follows: - cell cultures for 24 hours in complete culture medium,

removal of the complete culture medium, replacement with non-nutrient culture medium containing the oxidizing agent H2O2 for 3 h in the presence or absence of the active ingredients,

removal of the oxidizing agent and the non-nutritive culture medium, replacement with complete culture medium in the presence or absence of the active ingredients, Evaluation of the expression of MAP-LC3 after cellular recovery by immunofluorescent staining. The active ingredients tested were produced according to the following protocol:

solubilization of plant powder, algae or yeasts in water at a rate of 50 g / l (m / v),

- enzymatic hydrolysis,

separation of the soluble and insoluble phases,

f iltration and sterilizing f iltration. The main active ingredients are:

The results of the most effective active ingredients selected and tested in triplicate are described in the following table:

These active principles therefore make it possible to increase the autophagy of cutaneous cells subjected to moderate nutritional and oxidative stress, and thus detoxify the skin and prevent or fight against skin aging. These active ingredients can be incorporated into cosmetic compositions.

5. Examples of cosmetic compositions containing an active principle acting on the autophakia of cutaneous cells

The invention also covers cosmetic compositions including at least one active ingredient acting on the autophagy of cutaneous cells in different galenic forms, adapted for topical administration to the skin.

These compositions may especially be in the form of creams, oil-in-water emulsions, water-in-oil emulsions, multiple emulsions, solutions, suspensions or powders. They can be more or less fluid and have the appearance of a cream, a lotion, a milk, a serum, an ointment, a gel, a paste or a foam, or in solid form.

These compositions contain between 0.01 and 15% by weight of active principle (s) acting on autophagy cutaneous cells according to the present invention, preferably between 1% and 4%. 5.1. Expert cream

An example of a cream comprising an active ingredient extracted from lemon as presented in point 4, may have the following composition:

A. Water QSP 100% <9lycerol (Univar) 3.33%

EDTA 0.13 7

Satialgine (Degussa) 0.66 7 / o Talc (Luzenac) 1%

B. Miglyol 812 (Condea Chemie) 3.33 7 / o Ritaphyl ICS (Rita) 1.33 7

Ritachol SS (Rita) 1.33 7 / o Ipm (Univar) 3.33 7 Ritalan C (Rita) 1.33 7 / o Montanov 14 (Seppic) 1.33 7 Lanol 14M (Seppic) 1.33 7 / o

Brij 72 (Uniquema) 1% Brij 721 (Uniquema) 0.33 7 / o

C. Phenoxyethanol (Sigma) 0.9 ° / c _> Ethylhexylglycerin (Seppic) 0.1% D. Active ingredient from lemon according to the invention 4%

The cream is obtained by the implementation of the following steps:

- Heat A and B at 80 ⁰ C, with mechanical stirring,

emulsifying B in A with stirring,

at 30 ^° C. add C in order, and continue homogenization until the cream is uniform. 5.2. Αnti-wrinkle cream

An example of a cream comprising an active ingredient extracted from Lithothamnium as presented in point 4, can have the following composition:

A. Water QSP 100% Butylene glycol (Univar) 3%

B. Isohexadecane (Laserson) 5% Rita IPP (Rita) 2% Montanov 202 (Seppic) 3% Arlacel 161 (Uniquema) 1% Ritox 59 (Rita) 1%

Lanette O (Cognis) 1%

C. Phenoxyethanol (Sigma) 0.9% Ethylhexylglycerin (Seppic) 0.1% DC 200 (Dow Corning) 0.5% Active ingredient from Lithothamnium according to the invention 4%

D. Sepigel 305 (Seppic) 4% The cream is obtained by carrying out the following steps:

- mix A ₁ mix B and heat A and B at 80 ⁰ C, with mechanical stirring, - emulsify B in A with stirring,

at 30 ^° C. add C in the order, and

continue homogenization until the cream is uniform.

5.3. Night cream An example of a cream comprising an active ingredient extracted from Melilothus as presented in point 4, may have the following composition: A. Water QSP 100% Carbopol ETD 2020 (Noveon) 0.4%

B. cethylic alcohol (Stéarinerie Dubois) 3% Stearyl alcohol (Stéarinerie Dubois) 3% DUB MCT 5545 (Stéarinerie Dubois) 4.5%

DC 345 (Dow Corning) 7.5%

Monomuls 900 18 (Henkel) 3%

C. Phenoxyethanol (Sigma) 0.9% Ethylhexylglycerin (Seppic) 0.1% Active ingredient Melilotus according to the invention 4%

D. NaOH qsp pH 4.5 The cream is obtained by the implementation of the following steps:

- mix A, disperse the gel well and mix B,

heat A and B at 80 ^° C., emulsify B in A with stirring,

at 40 ⁰ C add C in the order,

continue homogenization until the cream is uniform,

- adjust the pH with D, and

- Cool with stirring to 30 ^° C. 5.4. Cream mature skin

An example of a cream comprising an active ingredient extracted from Candida saitoana as presented in point 4, may have the following composition: A. Water QSP 100%

Glycerol (Univar) 1.75% Propylene glycol (Univar) 6.5%

Aculyne 33A (ISP) 2.5%

Carbopol EDT 2020 (Goodrich) 0.5% B. Cetiol SN (Cognis) 3%

Eumulgine Bl (Cognis) 1.75%

Ritαphyl ICS (Ritα) 3%

Pαtlαc IL (Ritα) 3% Isopropyl myristαte (Univαr) 3%

Montαne 80 (Seppic)) 1.5%

Montαnox 60 (Seppic) 1.5%

DC 345 (Dow Corning) 3%

C. Phenoxyethenol (Sigma) 0.9% Ethylhexylglycerin (Seppic) 0.1%

D. Active ingredient from Candida saitoana 4% NaOH QSP pH 5.5

The cream is obtained by the implementation of the following steps:

- Mix A ₁ mix B, and heat A and B at 80 ⁰ C, - emulsify B in A with stirring,

at 30 ^° C. add C and D,

- adjust to pH 5.5 with NaOH, and

continue homogenization until the cream is uniform.

Claims

1. Use in a cosmetic composition of an effective amount of at least one autophagic activator of cutaneous cells as a cosmetic active ingredient.

2. Cosmetic use according to claim 1, as a cosmetic active ingredient intended to detoxify the skin and / or intended to prevent or fight against skin aging.

3. Cosmetic use according to claim 1 or 2, characterized in that said autophagic activator of cutaneous cells is an active ingredient having a stimulating activity of MAP-LC3 expression.

4. Cosmetic use according to one of the preceding claims, characterized in that said activator of autophagy cutaneous cells is an active ingredient having a stimulating activity of the expression of ATG5-12 cells of the skin.

5. Cosmetic use according to one of the preceding claims, characterized in that said activator of autophagy cutaneous cells is an active ingredient having a stimulating activity of the expression of the phosphorylated p53 protein.

6. Cosmetic use according to one of the preceding claims, characterized in that said activator of cutaneous skin autophagy is an active ingredient having a stimulating activity of DRAM expression.

7. Cosmetic use according to one of the preceding claims, characterized in that said activator of cutaneous skin autophagy is an active ingredient with a stimulating activity of the expression of AMPK.

8. Cosmetic use according to one of the preceding claims, characterized in that said activator of autophagy cutaneous cells is an active ingredient inhibiting the activation of phosphorylated mTOR.

9. Cosmetic use according to one of the preceding claims, characterized in that said activator of autophagy acts on the autophagic activity of keratinocytes and / or fibroblasts.

10. Cosmetic use according to one of the preceding claims, characterized in that said activator of skin cell autophagy is an active ingredient derived from at least one plant, an alga or a yeast.

11. Cosmetic use according to one of the preceding claims, characterized in that said activator of autophagy cutaneous cells is an active ingredient derived from at least one alga of the genus Lithothamnium calcareum, or a plant selected from Melilotus officinalis, Citrus limonum, Lens culinaris, Averrhoa carambola, Momordica charantia or a yeast selected from Candida saitoana and Yarrowia lipolytica.

12. Cosmetic composition for topical application to the skin comprising, in a physiologically acceptable medium, an effective amount of at least one autophagic activator for cutaneous cells selected from active ingredients derived from Lithothamnium calcareum, Melilotus officinalis, Citrus limonum, Candida saitoana, Lens culinaris, Averrhoa carambola, Momordica charantia, Yarrowia lipolytica and at least one cosmetic adjuvant.

13. Cosmetic composition according to claim 12, characterized in that said activator of autophagy cutaneous cells is present in an amount of between 0.1 and 15% by weight relative to the total weight of the composition.

14. Cosmetic process for detoxifying the skin and / or for preventing and / or combating cutaneous aging, comprising the topical application on the skin skin of a composition comprising at least activator of autophagy of skin cells.