Extract from meristematic cells of otanthus maritimus and uses thereof, in particular in cosmetics

Abstract

The present invention relates to an extract from meristematic cells of Otanthus maritimus, as well as to the non-therapeutic use thereof in cosmetics. The present invention also relates to a cosmetic or dermatological composition comprising the Otanthus maritimus extract, to a preparation method, and to a device comprising the Otanthus maritimus extract.

Description

AN EXTRACT OF MERISTEMA CELLS OF OTANTHUS MARITIMUS AND ITS USES, ESPECIALLY COSMETICS Technical field

[0001] The present invention relates to the cosmetic use of an extract of meristematic cells of Otanthus maritimus, as well as to a cosmetic or dermatological composition comprising the extract, and to a method and a device involving this composition.

[0002] The present invention finds its applications in particular in the field of cosmetics and dermatology, more particularly cutaneous cosmetics.

[0003] In the description below, the references in brackets ([ ]) refer to the list of references presented at the end of the text. State of the art

[0004] The skin is a vital organ in its own right, consisting of three distinct tissues, each performing different roles through different cell types and structures.

[0005] The most superficial and therefore the most exposed tissue is the epidermis. This multi-stratified (Squamous) and keratinized epithelium is composed of different cells associated with numerous barrier and protection functions. The majority of cells are keratinocytes, which divide in the basal layer and begin their differentiation up to the horny layer (the outermost layer), then are eliminated by desquamation, in 21 to 28 days, on average. The major role of the epidermis is to provide the skin, and therefore the human body, with a first line of protection against external aggressions, such as physical, chemical, water and bacteriological aggressions. This protection is notably ensured by the most differentiated layers and the horny layer, known for its hydrophobic properties, its compact and waterproof appearance. Good differentiation and therefore good desquamation are essential for a smooth, homogeneous and regular surface.All of these mechanisms depend. directly from the proliferative capacities of keratinocytes. However, external stresses and age slow down this process, which can then become longer and more irregular. As desquamation becomes irregular and / or anarchic, defects in the smoothing and homogeneity of the skin's surface occur.

[0006] In an intermediate position, the dermis is a connective tissue invested mainly with fibroblasts and matrix proteins giving the skin its known qualities of compressibility and elasticity. Changes in its texture and composition are largely responsible for the alterations in the skin that occur during aging. The relief of the stratum corneum is, moreover, directly conditioned by the quality and density of the dermis that underlies it. More than the epidermis, whose renewal is rapid and constant, the dermis undergoes significant age-related disorders, through the aging of its cells and its material. As we age, fibroblasts become less and less reactive and less and less proliferative. With age, the synthesis of matrix macromolecules is no longer ensured by fibroblasts.In addition, these macromolecules constituting the dermis such as collagen fibers, elastic fibers, proteoglycans and glycosaminoglycans (hyaluronic acid in particular) tend to degenerate and fragment. Their networks become disorganized and reoriented in parallel with the dermo-epidermal junction, particularly under the action of matrix protein degradation enzymes, MMPs (Matrix Metallo Proteases), also called collagenases or elastases. These phenomena of alteration of the dermal tissue cause a defect in the organization of the epidermis on the surface and, in a more visible and direct way, a loss of firmness which can lead to skin ptosis and / or the formation of wrinkles.

[0007] Within the connective tissue, other cells and structures are also interspersed, such as an important circulatory and nutritional network, made up of blood vessels and lymphatic capillaries, as well as the epidermal appendages: hair, body hair, nails, pilosebaceous glands and sweat glands, which originate in the deep dermis.

[0008] The hypodermis, located deep down and made up mainly of fatty lobules (adipocytes), provides a primary support function, mechanical and thermal protection and also plays a role in storing reserves. energy that can be quickly mobilized for all biological needs, such as cell renewal, body defense or muscle contraction.

[0009] The cosmetics market, particularly anti-aging products, is very large, and consumer expectations are very high. Across all product lines, consumer expectations are increasingly moving toward natural, effective, and eco-designed products.

[0010] Many plant-derived active ingredients are used in the cosmetic and dermatological fields, some of which have demonstrated good efficacy. However, many of these active ingredients come from imported plants, sometimes even endangered ones. Thus, it is increasingly necessary to develop active ingredients that do not threaten natural resources and are part of sustainable development.

[0011] There therefore remains a real need to find new active ingredients that are effective from a cosmetic and dermatological point of view and compatible with sustainable development. Description of the invention

[0012] The present invention aims precisely to meet these needs and drawbacks of the prior art.

[0013] The inventors are the very first to use an extract of Otanthus maritimus meristematic cells, which allows them to effectively meet the above-mentioned needs.

[0014] Otanthus maritimus is in fact a local plant, which the inventors have cultivated to obtain an active ingredient compatible with sustainable development.

[0015] Surprisingly, the inventors discovered cosmetic effects, including anti-aging, soothing and anti-inflammatory, of the extract of the invention. In particular, the inventors obtained results on the cell renewal of the epidermis, on the barrier function, including keratinocyte differentiation, and the inhibition of pro-inflammatory mediators.

[0016] Thus, a first object of the invention relates to an extract of meristematic cells of Otanthus maritimus.

[0017] Another subject of the invention relates to a non-therapeutic cosmetic use of the Otanthus maritimus extract of the invention.

[0018] Another subject of the invention relates to a cosmetic or dermatological composition comprising an extract of Otanthus maritimus of the invention.

[0019] Another subject of the invention relates to a device in a form chosen from a pot, a pump bottle, a wipe, a mask, a transdermal device, a patch, a spray, said device comprising a cosmetic or dermatological composition of the invention.

[0020] Another subject of the invention relates to a process for preparing a cosmetic or dermatological composition of the invention, comprising the mixture of an extract of Otanthus maritimus of the invention, and a cosmetically and / or dermatologically acceptable vehicle.

[0021] Otanthus maritimus, also called Achillea maritima, is a plant in the Asteraceae family. It is a perennial plant, 10 to 30 cm tall, with an aromatic scent. The stem, lying at the base then ascending, bears numerous small, sessile, oblong, crenate leaves with a rounded apex, a little fleshy.The leaves show morpho-anatomical adaptations to the ecological conditions of maritime dune systems: cottony leaves forming a sort of sleeve all around the stem, which delimits a very tight space maintaining a humid micro-atmosphere for protection against drying and heat, but which also serves as a passive defense against herbivores; an amphistomatic distribution (stomata on both leaf surfaces) which could be an adaptation to silting; hydathodes which excrete excess mineral salts; and a mesophyll consisting of an aquiferous parenchyma with cells enclosing a vacuole rich in mucilages, substances which absorb water.

[0022] For the purposes of the present invention, the term "meristematic cell extract" means a fraction of Otanthus maritimus comprising or consisting of at least one element chosen from cell walls of said meristematic cells, cell contents of said meristematic cells and whole meristematic cells. Advantageously, the extract may contain in in addition to metabolites of interest; these may be, for example, phenolic compounds such as caffeoyl quinic acids such as chlorogenic acid, 3,5-dicaffeoylquinic acid, polar compounds such as aspartic acid and simple sugars of the glucose or fructose type, or lipophilic compounds such as sterols and terpenes. The extract may be obtained according to any method known to those skilled in the art for isolating cells or cell fractions. This may be, for example, lysis of a cell culture of whole meristematic cells of Otanthus maritimus.

[0023] Meristematic cells of Otanthus maritimus can be obtained from in vitro culture of Otanthus maritimus cells. In vitro plant cell culture technologies began in 1939 with the demonstration of obtaining calli, which are clusters of undifferentiated cells also called meristematic cells. Their production on an industrial scale dates back to the 1990s (Trevor A. Thorpe. History of plant tissue culture. Molecular biotechnology, 2007, 37, 2, 169-180 ([1])). The principle consists, starting from a plant sample, of dedifferentiating the constituent cells of the sample, then subsequently inducing cellular multiplication of these meristematic cells. The goal is to increase the biomass so that the cells are recovered whole, or fragmented with a high concentration of metabolites of interest.This principle can be applied for the preparation of Otanthus maritimus extract comprising Otanthus maritimus meristematic cells. For example, Otanthus maritimus meristematic cells can be obtained, cultured and preserved according to the methods described in Plant cell culture technology in the cosmetics and food industries: current state and future trends, Regine Eibl & Philipp Meier & Irène Stutz & David Schildberger & Tilo Hiihn & Dieter Eibl, Applied Microbiology and Biotechnology (2018) 102:8661-8675 ([2]).

[0024] For example, whole meristematic cells of Otanthus maritimus can be treated in the following manner in order to obtain a meristematic cell extract: a) induction of explants and callogenesis, b) stabilization in solid medium, the solid medium being able to be any suitable medium known to those skilled in the art, c) stabilization of the growth in a liquid medium, the liquid medium being able to be any suitable medium known to those skilled in the art, d) elicitation, filtration then lysis, e) homogenization, f) drying, g) suspension of the lysate powder in glycerin, the suspension comprising for example from 2 to 5% of dry matter.

[0025] Advantageously, the extract obtained in step g) contains all or part of the metabolites of interest. Advantageously, the extract can be measured in total polyphenols expressed in cynarin equivalent (dicaffeylquinic acid).

[0026] The "metabolites of interest", within the meaning of the present invention, may be any compound or molecule produced by a plant or a part of a plant, in particular isolated cells of a plant, such as meristematic cells. They may be primary metabolites, for example sugars, proteins / amino acids and / or lipids. Alternatively or additionally, they may be secondary metabolites such as polyphenols, terpenes and / or alkaloids.

[0027] According to the invention, the Otanthus maritimus extract may be in any suitable form, in particular in the context of cosmetic use or in a dermatological composition. For example, the meristematic cells of Otanthus maritimus may be whole or lysed, may be suspended in liquid form or may be dried. In liquid form, the solvent used may be chosen from propylene glycol, butylene glycol, methylpropanediol, propane-1,3-diol, glycerin or a mixture of these solvents, this list not being limiting. The mixtures of these solvents may be made in all possible proportions allowing the technical effects mentioned below to be preserved. In dry form, the cell preparation may be obtained by vacuum evaporation, by atomization, by lyophilization or by any other suitable means known to those skilled in the art.Advantageously, the extract of the invention can be a dry form, obtained after lysis, drying and grinding, then suspended in glycerin.

[0028] In the context of the use of the Otanthus maritimus extract according to the invention, the use means a non-therapeutic use, for example for the treatment of normal skin, i.e. skin not presenting a pathological condition, to the exclusion of any therapeutic use. In other words, it is a purely aesthetic action aimed at improving the appearance of the skin. For the purposes of the present invention, the term "improving the appearance of the skin" means any effect making it possible to obtain an advantage on the appearance of the skin compared to the appearance of the skin before use of the extract according to the invention.

[0029] Advantageously, the cosmetic use according to the invention is at least one action chosen from an anti-aging action, a moisturizing action, a soothing action and an antioxidant action on the skin and / or mucous membranes.

[0030] For the purposes of the present invention, the term “mucous membrane” means in particular external mucous membranes such as the lips.

[0031] For the purposes of the present invention, the term "anti-aging action" means an action of preventing and / or delaying and / or limiting the signs of skin aging, in particular accelerated (exogenous) aging caused by environmental stresses, for example ultraviolet rays (photo-induced stress), or chronological aging (endogenous stress). The anti-aging action may involve at least one action chosen from stimulation of epidermal cell renewal, stimulation of the barrier function, in particular keratinocyte differentiation, stimulation of fibroblast cell cycle factors and reduction of the inflammaging phenomenon.The anti-aging effect may be at least one effect selected from skin regeneration, in particular via the protection of epidermal stem cells, prevention or reduction of skin sagging, reduction of senescence of skin cells, in particular dermal and / or epidermal cells, reduction of loss of skin firmness, reduction of loss of skin elasticity, a firming action, improvement of the biomechanical qualities of the skin or mucous membranes, and reduction or prevention of the formation of wrinkles and / or fine lines, in particular a reduction in the depth of wrinkles and / or fine lines of the skin or mucous membranes. Advantageously, the anti-aging action is an action. stimulation of the proliferation of epidermal keratinocytes, in favor of the renewal of the epidermis.

[0032] For the purposes of the present invention, the term "skin regeneration" means the metabolic stimulation of epidermal or dermal skin cells, the renewal of which is directly or indirectly linked to or targeted by intrinsic or extrinsic aging.

[0033] For the purposes of the present invention, the term "reduction of sagging / loss of firmness / loss of elasticity" means an action of inhibiting matrix metalloproteases (MMPs) which degrade the collagen and / or elastin of the skin, its appendages and / or mucous membranes. This may be an action of protection, and / or maintenance, and / or reinforcement of the existing fibers in the dermis (collagen and / or elastin) produced by the dermal cells. Advantageously, this action may make it possible to protect, maintain and / or improve the biomechanical qualities of the dermis, in particular the firmness, volume, density and resistance of the tissue.

[0034] For the purposes of the present invention, the term "moisturizing action" means any action of restoring, maintaining or strengthening the hydration of the skin or mucous membranes. Without wishing to be bound by a biological mechanism, the hydrating effect may be due to the improvement of the barrier function of the skin due to the extract of the invention, which could allow better water retention by the skin. Advantageously, the moisturizing action could allow the obtaining of softened skin, that is to say the obtaining of a silkier effect of the skin to the touch after use of the extract, and / or a reduction in the roughness effect of the skin to the touch.

[0035] For the purposes of the present invention, the term "soothing action" means at least one action chosen from the reduction of diffuse redness, improvement of the complexion, restoration of the complexion, restoration of skin texture, restoration of skin radiance, restoration of a more uniform skin luminosity, reduction of sensations of tightness, discomfort, tingling, diffuse heat, irritability of the skin. For the purposes of the present invention, the term "soothing action" may be understood to mean an anti-inflammatory type action against the unpleasant sensations felt by subjects with non-pathological sensitive / reactive skin. These unpleasant skin sensations can be due to environmental stress such as heat, cold, wind, sun, hard water, UV exposure, or sudden changes in temperature and air pollution, which can cause tingling, burning, redness or non-pathological but unsightly skin heating. Without wishing to be linked to a biological mechanism, this reaction can be explained by a decrease or inhibition of the expression of pro-inflammatory mediators induced following stress of any kind, which is the origin of the unpleasant sensations felt by the subjects. This may be, for example, the expression of interleukin 6 (IL6), interleukin 8 (IL8), matrix metalloproteinases (MMP) or Tumor Necrosis Factor alpha (TNFa) produced by epidermal keratinocytes.

[0036] For the purposes of the present invention, the term "antioxidant action" means any reduction, prevention or slowing down of the production of radical and / or oxidizing species, and / or of the oxidation of skin cells. Without wishing to be bound by a particular mechanism, the extract of the invention may increase in whole or in part the expression of cellular detoxification enzymes or proteins, or have an inhibitory action on the production of reactive oxygen species induced by oxidative stress.

[0037] For the purposes of the present invention, the term "cosmetic composition" means any composition for cosmetic purposes, i.e. aesthetic purposes, a composition which can be brought into contact with the superficial parts of the human body, for example the epidermis, the lips, the hair and capillary systems. Advantageously, a cosmetic composition makes it possible, exclusively or mainly, to protect them, perfume them, maintain them in good condition, modify their appearance or correct their superficial defects.

[0038] In this document, the term "dermatological composition" means any composition for dermatological purposes, i.e. a composition that can be brought into contact with the superficial parts of the human body, for treatment of the skin, mucous membranes, and appendages, such as nails, hair, or body hair. Such a composition may include additional active ingredients other than the extract of meristematic cells of Otanthus maritimus, which may be qualified as dermatological or therapeutic, which explains the “dermatological” quality of the composition.

[0039] “Cosmetically or dermatologically acceptable vehicle” means a vehicle suitable for use in contact with human and animal skin cells, in particular epidermal cells, without toxicity, irritation, undue allergic response and the like, and proportionate to a reasonable benefit / risk ratio.

[0040] The cosmetically acceptable vehicle may be chosen from water, allantoin, glycerin, methylpropanediol, this list not being exhaustive.

[0041] The composition of the invention may be obtained by any suitable method known to those skilled in the art for the manufacture of a cosmetic composition. This may, for example, be a simple mixture. Alternatively, it may, for example, be a method comprising a step of incorporating an internal phase into an external phase by means of an emulsifier, for example a rotor-stator type turbine. It may also, for example, be a method using Phase Inversion Temperature (PIT), this method being conventionally used by those skilled in the art to obtain oil-in-water emulsions whose dispersed droplets are particularly fine, for example with a diameter of 0.1 to 1 μm.

[0042] According to the invention, the cosmetic or dermatological composition may comprise 0.00001 to 5.0% by weight of said extract of meristematic cells of Otanthus maritimus relative to the total weight of the composition, for example from 0.0001 to 5.0% by weight, or from 0.001 to 5.0% by weight, or from 0.01 to 5.0% by weight, or from 0.02 to 5.0% by weight, or from 0.1 to 5.0% by weight, or from 0.3 to 5.0%, or from 0.5 to 5.0% by weight, or from 0.3 to 3.0%, or from 0.4 to 5.0%, or from 0.4 to 3.0%, or from 0.5 to 5.0%, or from 0.5 to 3.0%, or from 1.0 to 5.0% by weight, or from 2.0 to 4.0% by weight of said Otanthus maritimus meristematic cell extract relative to the total weight of the composition.

[0043] The cosmetic or dermatological composition of the present invention may be in any form suitable for cosmetic or dermatological. Advantageously, the composition may be a composition for topical use.

[0044] It may be, for example, a composition in a form chosen from the group comprising an oil-in-water or water-in-oil emulsion or a mixture of these emulsions.

[0045] According to the invention, the cosmetic or dermatological composition may, for example, be in a form chosen from the group comprising an aqueous or hydroalcoholic gel, an aqueous or hydroalcoholic cream and an aqueous or hydroalcoholic lotion. These formulations which can be used for implementing the present invention are known in the state of the art by formulators. In these composition examples, it is sufficient to add the extract of meristematic cells of Otanthus maritimus of the present invention to obtain a composition in accordance with the present invention.

[0046] According to the invention, the composition may be in a form chosen from an ointment, a cream, an oil, a milk, an ointment, a powder, a soaked pad, a solution, a gel, a serum, a balm, a butter, a lotion, a suspension, a soap or an emulsion.

[0047] The extract of the present invention may be used in a cosmetic or dermatological composition alone or in combination with other cosmetically or dermatologically active or inactive substances or ingredients. Inactive substances or ingredients are those which do not act cosmetically or dermatologically. These are the elements of the composition which in particular make it possible to accompany the extract, to constitute a particular formulation, to preserve the active extract over time, this list not being exhaustive. In other words, it may be any basic product which may be found in conventional cosmetic or dermatological compositions. In contrast, active substances or ingredients are those which in the intended cosmetic or dermatological application have an aesthetic and / or medical action.

[0048] Thus, the Otanthus maritimus meristematic cell extract of the present invention may be the sole active substance or ingredient of a composition, or it may be combined with other substances or active ingredients of a cosmetic or dermatological composition.

[0049] Other advantages may still appear to those skilled in the art upon reading the examples below, given for illustrative purposes. EXAMPLES OR METHODS OF IMPLEMENTATION

[0050] Example 1: Preparation of Otanthus maritimus meristematic cell extract

[0051] In the following examples, the preparation of a glycerin suspension of whole meristematic cells of Otanthus maritimus was prepared as follows: - induction of explants and callogenesis, - stabilization in a solid medium (Gamborg B5, sucrose, growth hormones, Agar Agar), - stabilization of growth in liquid medium (Gamborg B5, sucrose and growth hormones), - elicitation, filtration then lysis, - homogenization, - drying, and obtaining an extract of Otanthus maritimus in powder form (Otanthus-Powder), - suspension of the lysate powder in glycerin, the suspension comprising for example 2 to 5% dry matter.

[0052] Example 2: Effect of an extract of Otanthus maritimus meristematic cells obtained in Example 1 on the differentiation of keratinocytes

[0053] Normal human epidermal keratinocytes were incubated for 5 days in the presence of Otanthus maritimus meristematic cell extract. At the end of this incubation period, total RNA was extracted and keratin 10 gene expression was assessed by quantitative real-time RT-PCR.

[0054] The Othantus extract at 10'6 % and 10' 7 % causes overexpression of the gene coding for the protein K10 (keratin 10), representative of an induction of keratinocyte differentiation.

[0055] Keratin 10 gene expression level in normal human keratinocytes cultured in the presence of Otanthus extract

[0056] [Table 1]

[0057] Example 3: Effect of Otanthus maritimus meristematic cell extract on the inhibition of pro-inflammatory mediators

[0058] Normal human epidermal keratinocytes were treated or not (control) for 48 hours with a powdered extract solubilized in ethanol before dilution in the culture medium, of meristematic cells of Otanthus maritimus. 24 hours after the start of treatment, the cells were irradiated with UV at 593 kJ / m 2to induce an inflammatory process. Cell viability after irradiation and treatment is determined by mitochondrial activity (measurement of MTT hydrolysis). Pro-inflammatory cytokines IL6 and TNFa are measured in cell culture supernatants and quantified by ELISA method. The values ​​obtained are then related to cell viability.

[0059] The results show an inhibition of the production of inflammatory mediators by Otanthus extract, up to -48% of IL6 for 10' 6 % extract and - 55% TNFa for 10' 7 % extract.

[0060] The extract therefore has an anti-inflammatory effect.

[0061] [Table 2] Expression of IL6 and TNFa by UV-stimulated keratinocytes

[0062] Example 4: Effect of Otanthus maritimus meristematic cell extract on epidermal cell renewal

[0063] The effect of a powdered extract of Otanthus maritimus meristematic cells, solubilized in ethanol before dilution in the culture medium, on epidermal cell renewal was evaluated by studying the proliferation of a keratinocyte culture. To do this, normal human epidermal keratinocytes were incubated in the presence of the Otanthus maritimus meristematic cell extract or the positive control (PE+EGF) for 72 or 144 hours. Cell proliferation was evaluated by measuring a nuclear marker.

[0064] According to the results obtained, after 3 days (72h) of treatment, the extract of Otanthus maritimus tested at 10' 7 % and 10' 8 % (w / v) stimulates keratinocyte proliferation by +32% and +26% respectively. And after 6 days (144h) of treatment, it stimulates this process at the three concentrations tested: +28% at 10' 6 %, +56% at 10' 7% and +49% at 10' 8 %.

[0065] [Table 3] Epidermal keratinocyte proliferation (% compared to control) 0066] Otanthus maritimus extract significantly and significantly stimulates the proliferation of keratinocytes (up to +56% after 6 days of treatment at a concentration of 10' 7 %).

[0067] Example 5: Effect of Otanthus maritimus meristematic cell extract on the expression of dermal matrix markers

[0068] Normal human dermal fibroblasts were incubated for 48 hours in the presence of a powdered extract solubilized in ethanol before dilution in the culture medium, of Otanthus maritimus meristematic cells, or of TGF0 (positive reference). At the end of this incubation period, total RNA was extracted and gene expression of different dermal matrix markers was assessed by quantitative real-time RT-PCR.

[0069] A significant stimulation (fold change >2) of the expression of the genes COL1A1; COL3A1; EGFR; ERBB4; FN1; IGF1 R; IGF2; MMP14; MMP2; MMp7; MMp9; MSN; SERPINE1; SERPINE 2; TIMP2; TIMP3 was induced by Otanthus extract at 10' 6 % and 10' 7 %. The extract therefore induces a remodeling of the dermal matrix, in favor of an effect on the density of the dermis and its mechanical properties.

[0070] Example 6: Effect of Otanthus maritimus meristematic cell extract obtained in Example 1 on the migration of normal human fibroblasts

[0071] A wound was created on a cell lawn of normal human dermal fibroblasts using the WoundMaker™ system. The cells were then incubated in the presence of Otanthus maritimus meristematic cell extract and cell migration within the wound was monitored by image analysis for 72 hours.

[0072] In this study, the measured parameter is called Relative Wound Density (RWD). It evaluates the cell density inside the wound compared to the cell density outside the wound at each time point. This measurement is designed to be 0% at t = 0 and 100% when the cell density inside the wound is the same as the cell density outside the initial wound.

[0073] Under these experimental conditions, the Otanthus extract tested at 10' 6% allows to stimulate the fibroblast migration process over the entire kinetics, namely 72 hours (+15% the first 24 hours, and +12% over the following 2 days).

[0074] [Table 4] Table showing the results expressed as percentage of migration induction compared to the untreated control (100%).

[0075] Example 7: Effect of an extract of Otanthus maritimus meristematic cells on the inhibition of pro-inflammatory mediators in a chemical stress model (PMA)

[0076] For the following tests, the Otanthus maritimus extract was tested in suspended form in glycerin, as described in Example 1 (Otanthus-Gly), or in powder form (Otanthus-Powder), corresponding to the lysate obtained in Example 1 before suspension in glycerin.

[0077] Normal human epidermal keratinocytes were pre-incubated or not (control) in the presence of Othantus maritimus extract or the anti-inflammatory reference molecule (0.1 pM Dexamethasone). After 24 hours of incubation, the cells were stressed by adding 0.1 pg / ml of PMA (Phorbol-Myristate-Acetate) and incubated overnight to induce an inflammatory process.

[0078] Pro-inflammatory cytokines TNFα and IL8 were measured in cell culture supernatants and quantified by ELISA. In parallel, cell viability was measured for each condition. The technique uses the reducing power of viable cells to convert resazurin into fluorescent resorufin (PrestoBlue™ Assay). The values ​​obtained for TNFα and IL8 are thus related to viability. A Student t-test was performed to verify the significance of the results compared to the PMA control (NS Not Significant; *p<0.05; **p<0.01; ***p<0.001).

[0079] The results presented below show an inhibitory effect of Otanthus maritimus extract on the expression of inflammatory cytokines.

[0080] Table 5 shows the production of TNF-alpha and IL8 in keratinocytes subjected to chemical inflammatory stress induced by PMA - Protective effect of Otanthus-Gly and Otanthus-Powder. [00811 [Table 5]

[0082] Example 8: Effect of an extract of Otanthus maritimus meristematic cells on the inhibition of oxidative stress

[0083] For the following tests, the Otanthus maritimus extract was tested in suspended form in glycerin, as described in Example 1 (Otanthus-Gly), or in powder form (Otanthus-Powder), corresponding to the lysate obtained in Example 1 before suspension in glycerin.

[0084] Normal human epidermal keratinocytes were pre-incubated for 1 hour in the presence of the DCFH-DA probe (2',7'-dichlorodihydrofluorescein diacetate).

[0085] After rinsing, the cells were treated for 45 minutes with Otanthus maritimus extract or antioxidant reference molecules (Quercetin at 20pM, Vitamin C at 500pM) in the presence of hydrogen peroxide (H2O2) at 200pM. The production of reactive oxygen species (ROS) was evaluated by fluorescence measurement, proportional to the degradation of the DCFH-DA probe in contact with ROS.

[0086] A Student t test was performed to verify the significance of the results compared to the H2O2 stress control (*p<0.05; **p<0.01; ***p<0.001).

[0087] The results below show that the production of reactive oxygen species is lower in the presence of Otanthus maritimus extracts, in glycerin form, as in powder form, this demonstrating the protective effect antioxidant, and therefore detoxifying, effect of the extract on human epidermal keratinocytes.

[0088] The following tables show the expression of ROS in keratinocytes subjected to H2O2 stress - Protective effect of Otanthus-Gly (Table 6) and Otanthus-Gly (Table 7).

[0089] [Table 6] ROS expression in keratinocytes subjected to H2O2 stress - Protective effect of Otanthus-Gly. 0090] [Table 7] ROS expression in keratinocytes subjected to H2O2 stress - Protective effect of Otanthus-Powder.

[0091] Example 9: Effect of an extract of Otanthus maritimus meristematic cells on the protection of epidermal stem cells

[0092] The protective effect of Otanthus maritimus extract on epidermal progenitor cells (stem cells) was evaluated. In particular, the effect on colony forming efficiency (CFE), a key parameter of stem cell functionality linked to their clonogenicity, was studied under conditions of exposure to oxidative stress.

[0093] Keratinocyte progenitor cells (epidermal stem cells) were isolated and cultured for 48 hours in the presence of Otanthus maritimus extract suspended in glycerin, as described in Example 1. The cultures were then exposed to 15pM hydrogen peroxide (H2O2) for 15 minutes. The cells were then seeded for the CFE test, at the end of which the cultures were fixed and labeled and the colonies were counted.

[0094] The results presented in Table 8 show that Otanthus maritimus extract protects the clonogenic capacities of epidermal stem cells against stress induced by hydrogen peroxide. The results obtained at the doses tested are significant, even more so at the dose of 0.02%.

[0095] [Table 8] CFE (Colony Forming Efficiency) count - Protective effect of Otanthus maritimus extract - Statistical analysis: Student t test - * p<0.05

[0096] Example 10: Anti-senescence effect of an extract of Otanthus maritimus meristematic cells

[0097] The effect of Otanthus maritimus extract on senescence was evaluated on human dermal fibroblasts induced to senescence by successive replications (Hayflick model). The SASP (Senescence-Associated Secretory Phenotype) molecules produced by senescent cells were evaluated.

[0098] Senescent fibroblasts were incubated for 72 hours in the presence of Otanthus maritimus extract suspended in glycerin, as described in Example 1, or 5 pM Resveratrol (antisenescence reference molecule). SASP markers (IL8, MMP1) produced by senescent cells were assayed in culture supernatants by an ELISA method.

[0099] The results presented in Table 9 show that Otanthus maritimus extract inhibits the release of SASP molecules (IL8 and MMP1) in senescent fibroblasts.

[0100] Otanthus maritimus extract therefore has an anti-senescence effect.

[0101] [Table 9] Dosage of SASP released by senescent fibroblasts - Protective effect of Otanthus maritimus extract - Statistical analysis: ANOVA followed by Dunnett's test - * p<0.05; ***p<0.001

[0102] Example 11: Effect of an extract of Otanthus maritimus meristematic cells in a UV-induced aging model mimicking “inflamm'aging”

[0103] During chronological aging, low-grade systemic inflammation sets in.

[0104] This inflammaging process contributes to exacerbating the mechanisms that lead to the signs of skin aging.

[0105] The effect of Otanthus maritimus extract in powder form (Otanthus-Powder), corresponding to the lysate obtained in Example 1 before suspension in glycerin, was evaluated on fibroblasts subjected to induced UV aging. Under these UV stress conditions, fibroblasts express pro- inflammatory characteristics of inflamm'aging which contribute to the degradation of the dermal matrix and the exacerbation of cellular aging.

[0106] Human dermal fibroblasts were pre-incubated for 24 hours in the presence of Otanthus maritimus extract or the reference molecule (Dexamethasone 1 μM). The cells were then subjected to UVA irradiation (15J / cm 2 ), then incubated again in the presence of the extract or the reference for 48 hours. At the end of the incubation, the release of MMP1 and IL8 was quantified by ELISA assay.

[0107] The results in Table 10 show the significant protective effect of otanthus maritimus extract on UVA-induced secretion of IL8 and MMP1.

[0108] [Table 10] Dosage of inflammatory mediators released by fibroblasts subjected to UV stress - Protective effect of otanthus maritimus extract - Statistical analysis: Student's t-test - * p<0.05; **p<0.01; ***p<0.001; ns: not significant

[0109] Example 12: Formulation of the extract of meristematic cells of otanthus maritimus in a serum-type treatment

[0110] [Table 11]

[0111] Example 13: Formulation of Otanthus maritimus meristematic cell extract in a day cream

[0112] [Table 12]

[0113] Example 14: Formulation of Otanthus maritimus meristematic cell extract in a night cream

[0114] [Table 13] REFERENCES

[0115] Trevor A. Thorpe. History of plant tissue culture. Molecular biotechnology, 2007, 37, 2, 169-180.

[0116] Plant cell culture technology in the cosmetics and food industries: current state and future trends, Regine Eibl & Philipp Meier & Irène Stutz & David Schildberger & Tilo Hiihn & Dieter Eibl, Applied Microbiology and Biotechnology (2018) 102:8661-8675.

Claims

Claims

1. Extract of meristematic cells of Otanthus maritimus.

2. An extract according to claim 1, said extract comprising cell walls of said cells and / or cell contents of said cells and / or whole meristematic cells.

3. Extract according to claim 1 or 2, obtainable by lysis of a cell culture of whole meristematic cells of Otanthus maritimus.

4. Non-therapeutic cosmetic use of an extract of Otanthus maritimus as defined in any one of claims 1 to 3.

5. Non-therapeutic cosmetic use according to claim 4, for an anti-aging, moisturizing, soothing or antioxidant action on the skin and / or mucous membranes.

6. Cosmetic or dermatological composition comprising an extract of Otanthus maritimus as defined in any one of claims 1 to 3.

7. Cosmetic or dermatological composition according to claim 6, comprising 0.00001 to 5% by weight of said Otanthus maritimus extract relative to the total weight of the composition.

8. A cosmetic or dermatological composition according to claim 6 or 7, said composition being in a form chosen from an ointment, a cream, an oil, a milk, an ointment, a powder, a soaked pad, a solution, a gel, a serum, a balm, a butter, a lotion, a suspension, a soap or an emulsion.

9. Device in a form chosen from a pot, a pump bottle, a wipe, a mask, a transdermal device, a patch, a spray, said device comprising a cosmetic or dermatological composition as defined in any one of claims 6 to 8.

10. A process for preparing a cosmetic or dermatological composition as defined in any one of claims 6 to 8, comprising mixing an extract of Otanthus maritimus as defined in any one of claims 1 to 3, and a cosmetically and / or dermatologically acceptable vehicle.

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