WO2018229410A1

WO2018229410A1 - Cosmetic compositions comprising natural extracts and uses thereof

Info

Publication number: WO2018229410A1
Application number: PCT/FR2018/051360
Authority: WO
Inventors: Arnaud Sinan Karaboga; Michel Souchet
Original assignee: Harmonic Pharma
Priority date: 2017-06-13
Filing date: 2018-06-12
Publication date: 2018-12-20
Also published as: FR3067249A1; FR3067249B1; EP3638203A1

Abstract

The present invention relates to a cosmetic composition comprising a branch portion extract comprising at least approximately 50 wt % of polyphenols and less than approximately 10 wt % of terpenes, relative to the total weight of the extract, in a cosmetically acceptable medium. The invention also relates to the use of such a cosmetic composition for combatting the signs of skin ageing and/or for reinforcing the skin barrier.

Description

COSMETIC COMPOSITIONS COMPRISING NATURAL EXTRACTS AND

THEIR USES

TECHNICAL FIELD OF THE INVENTION

The present invention belongs to the field of natural extracts and in particular extracts of branch part. More particularly, the present invention relates to cosmetic compositions comprising such extracts and their uses for combating the signs of skin aging and / or for reinforcing the cutaneous barrier.

BACKGROUND OF THE INVENTION

Skin aging is determined by genetic and environmental factors. One distinguishes on the one hand the intrinsic aging, or chronological, which affects the skin and corresponds to the inevitable modifications of the latter related to the age. On the other hand, there is extrinsic aging, which corresponds to clinical, histological and functional changes characteristic of the skin linked to environmental factors such as exposure to the sun, pollution, tobacco, etc., and which thus occupies more especially on exposed areas.

These two aging processes are closely associated and in both cases, the production of reactive oxygen species (ROS), leading to oxidative stress is a determining element of aging of the skin. Oxidative stress is similar to an excess of free radicals present in the body and excessively produced by various physiological mechanisms or exogenous toxic phenomena such as tobacco, pollution or exposure to UV. These ROS and free radicals can thus be generated in particular by cellular metabolism, such as mitochondrial respiration, xenobiotic detoxification and solar radiation.

In principle, the physiological production of free radicals is controlled by cellular defense systems. However, these may be affected by various factors such as antioxidant deficiency or decreased activity of antioxidant enzymes or again by the overproduction of ROS and free radicals, leading to an imbalance of the redox balance and thus to a state of oxidative stress.

It is widely accepted that oxidative stress plays a vital role in aging skin. Indeed, the degradation of lipids and cutaneous proteins under the effect of oxidative stress causes sagging skin, the formation of wrinkles and pigment spots, and a loss of elasticity of the skin and radiance of the complexion. In addition, it was observed that nitric oxide produced in excess during an imbalance of the redox balance, that is to say during a state of oxidative stress, inhibited the synthesis of the proteins necessary for corneification of the epidermis and thus disrupted the barrier function of the skin.

It is thus better understood that it is advantageous to have means for effectively protecting the skin against oxidative stress. WO 2007/096089 provides cosmetic or dermatological preparations comprising hydroxymatairsinol for lightening the skin of age spots or for the prevention of tanning of the skin caused especially by UV rays.

US 2005/0169947 proposes cosmetic formulations based on lignans having an antioxidant effect, including in particular hydroxymatairsinol, lariciresinol, or secoisolariciresinol.

However, there remains a need to develop new cosmetic compositions that effectively fight against the signs of skin aging and / or strengthen the skin barrier.

SUMMARY OF THE INVENTION

In this context the inventors have developed new cosmetic compositions comprising a branch portion extract enriched in polyphenols, which have interesting antioxidant properties to fight against the signs of skin aging and / or to reinforce the cutaneous barrier. In particular, the inventors have demonstrated by different methods that the branch portion extract included in the compositions of the invention has antioxidant and antiradical activities superior to the activities of the reference compounds such as pycnogenol, Γα-tocopherol (Vitamin E), but also the activities of its main metabolites such as enterolactone and enterodiol.

The subject of the present invention is therefore a cosmetic composition, in particular for combating the signs of skin aging and / or for reinforcing the cutaneous barrier, comprising a branch portion extract in a cosmetically acceptable medium, in which said part extract of branch comprises at least about 50% by weight of polyphenols and less than about 10% by weight of terpenes, based on the total weight of the extract.

The subject of the invention is also the cosmetic use of such a composition for combating the signs of skin aging, in particular the formation of wrinkles, sagging skin and loss of radiance of the complexion, due in particular to exposure. UV, tobacco and / or pollution and / or to reinforce the skin barrier.

The invention also relates to a cosmetic process for combating the signs of skin aging, in particular the formation of wrinkles, sagging skin and loss of radiance of the complexion, due in particular to exposure to UV, tobacco and or the pollution and / or to reinforce the cutaneous barrier, comprising the topical application to the skin of the composition according to the invention.

LEGEND OF FIGURES

Figure 1: Evaluation of the antiradical activity of the extract according to the invention (natural extract), hydroxymatairsinol (HMR), enterodiol, enterolactone, and pycnogenol by the DPPH method.

Figure 2: Evaluation of the antioxidant activity of the extract according to the invention (natural extract) and its main metabolites (enterodiol and enterolactone), expressed in trolox equivalent (square units) and vitamin E (dotted line).

FIG. 3: Evaluation of the total antioxidant capacity of the extract according to the invention (natural extract), of pycnogenol, and of hydroxymatairsinol (HMR), expressed in millimoles of total antioxidant per gram of product, by PAOT technology. POT ^® . FIG. 4: Evaluation of the total antioxidant efficacy of the extract according to the invention (natural extract) and of its main metabolites (enterodiol and enterolactone), expressed in millimoles of total antioxidant per gram of product, using PAOT / POT ^® . DETAILED DESCRIPTION OF THE INVENTION

The inventors have developed and identified novel compositions comprising a branch portion extract in a cosmetically acceptable medium, wherein said branch portion extract comprises at least about 50% by weight of polyphenols and less than about 10% by weight of terpenes, based on the total weight of the extract. As demonstrated in the examples, the cosmetic composition comprising such a branch portion extract has a high antioxidant and antiradical power and can thus be used in cosmetic applications, in particular to fight against the signs of skin aging and / or to reinforce the barrier skin. In addition, the polyphenols present in the branch portion extract of the invention have an antioxidant and antiradical potency superior to their metabolites, thus illustrating an improved efficacy of the topical route for combating the signs of skin aging and / or strengthening the cutaneous barrier compared to an oral route that metabolizes these polyphenols.

Branch Part Extract Typically, the branch portion extract according to the invention is obtained by a standard extraction method of a branch portion of the trees, preferably softwoods comprising the following steps: (a) extraction, (b) liquid / solid separation (filtration), (c) concentration, and (d) drying. Preferably, the branch portion extract is a dry extract. As used herein, the term "branch portion" refers to that portion of the tree excluding the trunk. Part of a branch includes, for example, leaves, bark, stems, buds, and knots of wood. In a particular embodiment, the "branch part" excludes the nodes of the wood. In another particular embodiment, the "branch part" comprises the leaves, the bark, the stems and the buds, and is in particular devoid of knots of the wood. The branch portion extract of the cosmetic compositions according to the invention comprises at least about 50%, 60%, 70%, preferably 80%, more preferably at least about 90% by weight of polyphenols and less than about 10%, 8%, 6%, preferably less than about 5% by weight of terpenes, based on the total weight of the extract.

Polyphenols are a structural class of chemical compounds characterized by the presence of large numbers of phenol structural units. Polyphenols can also be called "lignan" when they are present in plants. As an example of polyphenol or lignane present in softwoods, the following can be mentioned:

the hydroxymatairsinol (HMR) corresponding to the following formula:

- the lariciresinol corresponding to the following formula:

secoisolariciresinol corresponding to the following formula:

and

- the liovile corresponding to the following formula:

Preferably, the polyphenols of the branch portion extract according to the invention are selected from the group consisting of hydroxymatairsinol (HMR), lariciresinol, secoisolariciresinol and their epimers.

As used herein, the term "epimer" refers to diastereoisomers which differ in configuration by a single stereogenic center. The term "diastereoisomer" refers to a class of non-superimposable stereoisomers without a mirror image of another. For example, "epimeres of hydroxymatairsinol" denote the diastereoisomers 7S, 8R, 8'R and 7R, 8R, 8'R as illustrated in the following formula:

In a preferred embodiment, the branch portion extract according to the invention comprises:

about 25 to about 50% by weight of hydroxymatairsinol,

about 5 to about 15% by weight of lariciresinol, and

about 5 to about 15% by weight of secoisolariciresinol,

relative to the total weight of the extract. As used herein, the term "about" will be understood by those skilled in the art and will vary to a certain extent depending on the context in which it is used. If certain uses of the term are unclear to those skilled in the art depending on the context in which it is used, "about" will mean "up to plus or minus 10, preferably 5%" of the particular term. The branch portion extract of the cosmetic compositions according to the invention having an improved antioxidant effect is enriched in polyphenols compared to terpenes, and in particular comprises less than about 10% by weight of terpenes, based on the total weight of the terpenes. 'extract.

Terpenes are a large, diverse class of organic compounds, produced by various plants, especially softwoods. The terpenes are derived by biosynthesis from isoprene units of molecular formula represented by the following formula:

As main terpenes present in softwoods, o-guaicol, terpin hydrate, vanillin, 2,5-dimethylbenzenebutanoic acid, conifeyl alcohol, tumérone, juvabione, dehydrojuvabione, manol, and eucalyptol (1,8-cineol) can be mentioned.

The branch portion extract of the cosmetic compositions according to the invention may further comprise any other compound present in softwoods in a small amount such as the terpenes as mentioned above, and, typically, eucalyptol (1,8- cineol). However, since eucalyptol is known for its toxicity, it is preferably present in small amounts, preferably less than about 10% by weight, more preferably less than about 2, and more preferably less than about 1% by weight. relative to the total weight of the extract. In a preferred embodiment, the branch portion extract comprises less than 1% by weight of eucalyptol, based on the total weight of the extract.

In a particular embodiment, the branch portion extract of the cosmetic composition according to the invention is a tree extract selected from Abies alba, Picea abies, Betula pendula, Pinus sylvestris, Abies sibirica, Pinus sibirica, Abies balsamea , Thuja occidentalis, Northern white-cedar, Pinus cembra, Pseudotsuga menziesii, Larix decidua, Picea glauca, Picea mariana, Picea pingens, Abies pectinata, Abies lasiocarpa, Pinus banksiana, Pinus nigra, Pinus pinaster, Pinus resinosa, Larix lariciana, Larix sibirica , Thuja plicata, Fagus sylvatica, Populus alba, Populus nigra, Populus tremula, Populus tremulus, Tsuga hetewphylla, Pinus contorta, Juniperus virginiana, and mixtures thereof. In a preferred embodiment, the branch portion extract is derived from at least one softwood, preferably selected from Abies alba, Picea abies, Pinus sylvestris, Abies sibirica, Pinus sibirica, Abies balsamea, Thuja occidentalis, Northern white- cedar, Pinus cembra, Pseudotsuga menziesii, Larix decidua, Picea glauca, Picea mariana, Picea pingens, Abies pectinata, Abies lasiocarpa, Pinus banksiana, Pinus nigra, Pinus pinaster, Pinus resinosa, Larix lariciana, Larix sibirica, Thuja plicata, Tsuga hetewphylla, Pinus contorta, Juniperus virginiana, and their mixtures. More preferably, the branch portion extract is a branch portion to Abies alba and / or Picea abies.

Cosmetic composition

The cosmetic composition comprises a branch portion extract as described above in a cosmetically acceptable medium. This composition comprising such an extract is therefore particularly suitable for combating the signs of cutaneous aging and / or reinforcing the cutaneous barrier.

According to a preferred embodiment of the invention, the branch portion extract as described in the present application is an active ingredient of the cosmetic composition. According to an even more preferred embodiment of the invention, the branch portion extract as described in the present application is the sole active ingredient of the cosmetic composition. According to these preferred embodiments, the branch portion extract is therefore not used in the cosmetic composition as a simple excipient, for example by playing a possible role of stabilizer of the cosmetic composition by virtue of its antioxidant properties. In contrast, according to these preferred modes, the branch part extract plays a role of principle or active ingredient in the cosmetic composition by providing it with the antioxidant and antiradical properties useful for combating the signs of skin aging and / or to strengthen the skin barrier. According to one particular embodiment, the composition according to the invention comprises at least about 0.1, preferably at least about 1, at least about 5, at least about 10, and even more preferably between about 10% and 50%. weight of the branch portion extract as described above with respect to the total weight of the composition. Cosmetically acceptable medium means a medium compatible with the skin and the mucous membranes, that is to say a non-toxic medium tolerated by the subject which, for example, does not generate tingling, irritation, allergic response or redness inconsistent with cosmetic use.

The cosmetically acceptable medium of a composition according to the invention may comprise any excipient known to those skilled in the art and adapted to the type of application of the composition.

These include sequestering agents, antioxidants chelating agents, sunscreens, preservatives, fillers, electrolytes, humectants, dyes, perfumes, essential oils, cosmetic active agents, moisturizers, vitamins, acids and the like. essential fatty acids, sphingolipids, soothing and skin-protecting agents such as allantoin, propenetrating agents, emulsifiers, gelling agents, thickeners, buffering agents, lipophilic excipients, disintegrating agents, soluble agents, compression agents or a mixture thereof. Of course, those skilled in the art will take care to choose this or these optional excipients, and / or their quantity, such that the advantageous properties of the composition according to the invention are not, or not substantially impaired. As preservatives, there may be mentioned, for example, quaternary ammoniums such as benzalkonium chloride; phenoxyethanol; benzyl alcohol; diazolidinylurea; parabens, such as methylparaben, propylparaben or butylparaben; benzoic acid and its sodium or potassium salts such as sodium benzoate; sorbic acid and its sodium or potassium salts such as potassium sorbate; mercurial derivatives such as phenylmercury salts (acetate, borate or nitrate) or thiomersal; or their mixtures.

As humectants, mention may in particular be made of glycerine and sorbitol. As propenetrating agents, mention may in particular be made of propylene glycol, dipropylene glycol, propylene glycol dipelargonate, lauroglycol and ethoxydiglycol.

As fats, mention may be made in a nonlimiting manner of oils, in particular mineral oils (vaseline oil), oils of vegetable origin (avocado oil, soybean), oils of animal origin (lanolin), synthetic oils (perhydrosqualene), silicone oils (cyclomethicone) and fluorinated oils (perfluoropolyethers). It is also possible to use fatty alcohols such as cetyl alcohol, fatty acids, waxes and gums, in particular silicone gums, as fatty substances.

Examples of emulsifiers and coemulsifiers that may be mentioned include fatty acid esters of polyethylene glycol, such as PEG-100 stearate, PEG-50 stearate and PEG-40 stearate; fatty acid esters of polyol such as glyceryl stearate, sorbitan tristearate and oxyethylenated sorbitan stearates available under the trade names Tween 20 or Tween 60, for example; and their mixtures.

As gelling agents, mention may be made of the family of polyacrylamides, such as the mixture Sodium acryloyldimethyltaurate copolymer / isohexadecane / polysorbate 80 sold under the name Simulgel ™ 600 by the company Seppic ™, the polyacrylamide / isoparaffin mixture C13-14 / laureth-7, for example for example, the product sold under the name Sepigel 305 ™ by the company Seppic ™, the family of acrylic polymers coupled to hydrophobic chains, such as the PEG-150 / decyl / SMDI copolymer sold under the name Aculyn 44 ™ (polycondensate comprising less as elements, a polyethylene glycol with 150 or 180 moles of ethylene oxide, decyl alcohol and methylene bis (4-cyclohexyl isocyanate) (SMDI), at 35% by weight in a propylene glycol mixture (39%) and water (26)), the family of modified starches such as modified potato starch sold as Solanace ™ Structure or mixtures thereof.

As thickening agent, mention may be made of polysaccharides such as xanthan gum, gum tragacanth, carrageenans such as λ-carrageenan, κ-carrageenan or i-carrageenan, galactomannans such as locust bean seed meal, guar seed meal or tara seed meal, gellan gum, gum arabic, karaya gum, pectin, starch and its derivatives obtained by esterification or etherification, and tamarind; cellulose derivatives such as methylcellulose, ethylcellulose, ethylmethylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose and hydroxyalkylcelluloses such as hydroxyethylcellulose, hydroxymethylcellulose, hydroxypropylcellulose and hydroxypropylmethylcellulose; and carboxyvinyl polymers of Carbopol ^® type. The administration of the cosmetic composition may be carried out orally, topically, parenterally, subcutaneously, epicutaneously, intradermally, transdermally, intramuscularly, enterally, intranasally, intrasfinctively or by nasal inhalation, preferably topically.

According to a preferred embodiment of the invention, the cosmetic composition is a topical or dermatological composition. The composition according to the invention can also be called a dermo-cosmetic composition. This topical composition can therefore be in any form suitable for topical application to the skin. It is thus envisaged compositions in the form of solutions, lotions, gels, ointments, emulsions of liquid or semi-liquid consistency of the milk type, obtained by dispersion of a fatty phase in an aqueous phase (H / E) or conversely (W / O), or powders, soaked swabs, sprays, suspensions or emulsions of soft, semi-liquid or solid consistency of the cream, ointment or micro-emulsion, micro-capsule type , microparticles or vesicular dispersions of ionic and / or nonionic type. It can also be in the form of microspheres or nanospheres or lipid or polymeric vesicles or in the form of polymeric patches and hydrogels allowing controlled release. These compositions are prepared according to the usual methods.

Preferably, the topical cosmetic composition is in the form of a gel, a lotion, or a cream. In a particular embodiment of the invention, the cosmetic composition further comprises an anti-aging active ingredient. Examples of such anti-aging active agents include: ascorbic acid, its salts, its ethers and its esters, especially ascorbyl glucoside; adenosine; ribose; honey extracts; proteins and glycoproteins, extracted in particular from sweet almonds; hydrolysed vegetable proteins, in particular derived from rice, hibiscus seeds or lupine; polypeptides and dipeptide such as carcinine hydrochloride, pentapeptide-4 palmitoyl (Pal-Lys-Thr-Thr-Lys-Ser) and palmitoyl tripeptide-38 sold for example by Sederma under the trade names Matrixyl ^® 3000 and Matrixyl ^® Synthe'6, respectively, the palmitoyl tripeptide-8 marketed by LUCAS MEYER under the trade name Nutrazen ^® , pentapeptide-18 marketed by Lipotec under the trade name Leuphasyl solution, the sh-decapeptide-9 marketed by SANDREAM company under the trade name neoendorphin ^® hexapeptide and palmitoyl-52 marketed by Infinitec under the trade reference X50 Myocept ^® Powder; silanes such as methylsilanol mannuronate; arabinoxylans, extracted in particular from rye flour and galactoarabinans, especially from larch; hyaluronic acid and its salts; polyphenols, extracted in particular from mimosa; alpha-hydroxy acids, including those extracted from lemon; extracts (generally aqueous) of plants such as water clover, wild pansy, field horsetail, Mafane (Acmella oleracea), donkey thistle (Onopordum acanthium), Yarrow (Achillea millefolium, contained in particular in product Neurobiox ^® from BASF), the Embelia (Embelia concinna, as marketed by Seppic), the prickly pear (Opuntia ficus indica, sold especially by MIBELLE BIOCHEMISTRY AG under the trade name AquaCacteen ^®), the salvia (Salvia officinalis, sold in particular by PROVITAL GROUP), Vitex negundo (marketed in particular by LABORATORIES EXPANSCIENCE under the trade name Neurovity ^® ), chestnut, papaya, argan, oats, sunflower, daisy, peony or dill; aqueous extracts of algae including coralline, red janie, Ungaria pinnatifada, Alaria esculenta or Nannochlorosis oculata; essential oils, including myrtle; zinc gluconates and / or copper; and their mixtures.

Also, the composition according to the invention may further comprise at least one tensor polymer, that is to say able to stretch the skin by mechanical action and thus reduce the appearance of wrinkles and fine lines. It may be a synthetic or natural polymer, in particular a polysaccharide, especially an extract of seaweed or marine plankton or a vegetable gum.

Thanks to its antioxidant and antiradical properties, the cosmetic composition of the invention is adapted to fight against the signs of skin aging and / or to reinforce the cutaneous barrier.

The signs of skin aging result, for example, in the formation of wrinkles, sagging skin, loss of radiance of the complexion. These signs may be due to factors intrinsic to age but also by extrinsic factors such as UV exposure, tobacco, and pollution.

The present invention therefore also relates to the use of a composition as defined above for combating the signs of skin aging, in particular the formation of wrinkles, sagging skin and loss of radiance of the complexion, due in particular to exposure to UV, tobacco and / or pollution and / or to reinforce the skin barrier.

The present invention also relates to a cosmetic method for combating the signs of skin aging, in particular the formation of wrinkles, sagging skin and loss of radiance of the complexion, due in particular to exposure to UV, tobacco and / or to pollution and / or to reinforce the cutaneous barrier, comprising the topical application to the skin of the composition as defined above. This composition can be applied one or more times a day, for example morning and / or evening on the areas to be treated.

The examples which follow serve to illustrate and show other aspects and advantages of the invention and must be considered as being nonlimiting.

EXAMPLES

EXAMPLE 1 Cosmetic Compositions According to the Invention 1. Method for Extracting Branch Part Extracts

54 kg of natural raw material consisting of the branch part of Picea abies and Abies alba were placed in an extractor (eg Lavergne-type filter extractor equipped with a nylon membrane) and extracted with using 15% ethanol in water (v / v) as a solvent at a raw material / solvent ratio of 1/10 to 40 ° C for 24 hours. The liquid / solid separation was obtained using a centrifugal dryer. The solid extract was placed in said extractor and was extracted with 15% ethanol in water (v / v) as a solvent at a material / solvent ratio of 1/10 to 40%. ° C for 1 hour. The liquid / solid separation was obtained using a centrifugal dryer. The two liquid extracts were combined and the concentration of the liquid extract was carried out under vacuum at 60 ° C using a evaporator (eg Wiegand falling curtain). The drying of the extracts was carried out by atomization using a stainless steel spray dryer (eg PSD 52 atomizer tower) to obtain 3.88 kg of solids. 2. Process for preparing the compositions according to the invention

The branch part extract obtained above is formulated in the cosmetic compositions according to the invention by any method known to those skilled in the art for formulating cosmetic compositions. In particular, those skilled in the art will be able to adapt the cosmetically acceptable medium in which the branch part extract will be added in order to obtain the type of formulation desired.

Example 2 Evaluation of Antioxidant and Anti-Radical Activities of Branch Part Extracts According to the Invention 2.1. DPPH test (2,2-diphenyl-1-picryrhydrazyl)

(Burda and Oleszek: "Antioxidant and anti-radical activities of flavonoids", J. Agric Food Chem., 2001, 49, 2774-2779).

To study the antiradical activity of the extract, the DPPH test was used. The free radical DPPH has a violet color which becomes yellow when it is reduced in the presence of radical compounds. The intensity of the color, measured spectrophotometer, is inversely proportional to the antiradical activity of the compounds tested. Various dilutions of bee samples dissolved in methanol were added to 3.9 ml of a methanolic solution of DPPH-6, 1x10 ^-5 M. The initial true DPPH concentration (C DPPH) in the medium of The reaction was calculated using a standard curve and the bleaching of DPPH was monitored at 517 nm (spectrophotometer) for 30 minutes against a blank sample consisting of all reagents except DPPH. "DPPH specimen trapping activity was expressed as IC50 (mg / mL) and extrapolated from a dose-response curve. carried out in quadruple (n = 4) with the extract according to the invention, hydroxymatairsinol (HMR), enterodiol, enterolactone, and pycnogenol® (extract of French maritime pine bark, reference antioxidant compound The antiradical activity is expressed as an EC50 value (the EC50 value most s small corresponds to the strongest antioxidant activity). As illustrated in FIG. 1, the antioxidant activity of the branch portion extract according to the invention is greater than that of HMR, enterodiol, enterolactone, and pycnogenol. Indeed, the branch portion extract according to the invention shows, against all odds, an EC50 value (concentration effective to reduce 50% of the DPPH radicals) of 0.13 mg / ml which is smaller than the EC50 value of the HMR (EC50 = 0.20 mg / ml) and pycnogenol (EC50 = 0.21 mg / ml).

In addition, the extract according to the invention shows an EC50 value of 0.13 mg / ml which is smaller than the EC50 value of its metabolites - namely, enterodiol (EC50 = 0.28 mg / ml) and enterolactone (EC50 = 0.30 mg / ml).

2.2. Trolox Equivalent Antioxidant Capacity Test (TEAC)

(Re R., Pellegrini N., Proteggente A., Pannala A., Yang M., Rice-Evans C: "Antioxidant activity applying an improved ABTS radical cation decolorization assay", Free Radical Biology & Medicine, 1999, 26 (9 ), 1231-1237).

The total antioxidant activity of the extract according to the invention derives from its capacity to inhibit the radical ABTS ⁺ , obtained from ABTS (ammonium salt of 2,2'-azinobis acid). ethylbenzothiazolin-6-ulfonic)) compared to a reference antioxidant compound (pycnogenol®, α-tocopherol, Trolox) and its metabolites (enterodiol and enterolactone). The ABTS cationic radical (ABTS ⁺ ) was produced by reacting a stock solution of 7 mM ABTS with 2.45 mM potassium persulfate and allowing the mixture to stand in dim light at room temperature for 12 minutes. h before use. The ABTS · ^{+ solution} was then diluted with PBS (phosphate buffered saline) (pH 7.4) to an absorbance of 0.5 at 734 nm and equilibrated at 30 ° C. Solutions of 200 μl of ABTS ⁺ and (10, 20, 35, 50, 70, 80 μl) of product (0.5 mg / l) were mixed and adjusted to 300 μl with the buffer solution. After a 15 min incubation, the optical density was measured. The tests were performed in quadruple (n = 4). Efficiency is expressed as EC50 value (the lowest EC50 value is the highest antioxidant activity).

Unexpectedly, the natural extract according to the invention shows the smallest EC50 value (concentration effective to eliminate 50% of ABTS at equilibrium) with a value of 0.020 mg / ml in this test, as indicated in the Table. 1 below. Table 1: EC50 values obtained in the TEAC test

In addition, Figure 2 highlights the striking divergence in antioxidant efficacy between the branch part extract and its major metabolites. In fact, the antioxidant activity of 1 g of the natural extract is equivalent to 1.07 g of trolox (square units) and 1.53 g of vitamin E (dotted line) while the antioxidant activity of 1 g of of enterolactone is equivalent to 0.13 g of trolox (square units) and 0.19 g of vitamin E (dotted), and the antioxidant activity of 1 g of enterodiol is equivalent to 0.15 g of trolox ( square patterns) and 0.22 g of vitamin E (dotted line).

2.3. Free radical absorbance capacity test (ORAC)

(Or B., Hampsch-Woodill M. and Prior RL: "Development and Validation of an Improved Oxygen Radical Absorbance Capacity Assay Using Fluorescein as Fluorescent Probe", J. Agric., Food Chem., 2001, 49 (10), 4619 -4626)

Measurement of antioxidant capacity by the ORAC method is based on the detection of the fluorescence of a fluorescein drop (FL) by its reaction with the peroxyl ROO * radical, in a food matrix containing antioxidant compounds. The fluorescence was read at an excitation wavelength of 485 nm and at an emission filter of 528 nm. The AAPH solution and FL were prepared in a 75 mM phosphate buffer solution, pH 7.4. The control of this reaction is trolox which is also prepared in the same buffer. Six different amounts (10, 20, 35, 50, 70, 80 μΐ) of product at a concentration of 0.5 mg / L were placed in the wells of a microplate with the FL and adjusted to the same volume with the solution. buffer (80 μΐ). The mixture was preincubated for 30 min at 37 ° C., before rapid addition of the AAPH solution (220 μl) using a multichannel pipette. The microplate was immediately placed in the reader and the fluorescence recorded every 6 min for 240 min. A blank sample with FL and ΓΑΑΡΗ using sodium phosphate buffer instead of the antioxidant solution was used. Inhibitory capacity was expressed in reference compound equivalents (μΜ), and is quantified by integrating the area under the curve (AUC) of fluorescein. The tests were performed in quadruple (n = 4). The effectiveness of the tested samples is expressed in reference ORAC units by gram of products (the highest value corresponds to the strongest antioxidant activity). The results are shown in Table 2.

Table 2: Antioxidant activity of the branch part extract according to the invention, pycnogenol, HMR, enterodiol, and enterolactone. The values are expressed in equivalent units (μιηοΐ of reference compound per gram of product tested).

The results show that the antioxidant activity of 1 gram of the branch part extract is respectively equivalent to the total antioxidant power of 2,400 μιηοΐ of trolox, 1,300 μιηοΐ of vitamin C, 1,200 μιηοΐ of vit. E (tocopherol), and 310 μιηοΐ of β-carotene. Unexpectedly, the antioxidant activity of the branch part extract is much greater than the antioxidant activity of 1 g of pycnogenol, 1 g of hydroxymatairsinol (HMR) and 1 g of the metabolites of the natural extract (enterodiol and enterolactone).

2.4. Total antioxidant power test (PAOT®) (oxidative stress)

PAOT / POT® (Total Antioxidant / Total Oxidative Power) technology is based on the electrochemical nature of redox reactions: balance between antioxidants and oxidants [www.ie-antioxydants.com]. The tests were performed in quadruple (n = 4). (The highest value is the best antioxidant efficiency).

As illustrated in FIG. 3, the overall antioxidant efficacy of the natural extract according to the invention (10.31 mmol / g in antioxidant equivalents) is, against all odds, better than that of pycnogenol (8.82 mmol / g in equivalents antioxidant), and HMR (4.99 mmol / g in antioxidant equivalents). Table 3 below summarizes the antioxidant activity values of the natural extract, pycnogenol, and HMR compared to reference antioxidant compounds, namely, vitamin E (tocopherol), trolox, and β-carotene. Against all odds, the branch part extract shows the best antioxidant activity among the products tested. Indeed, 1 gram of branch part extract according to the invention is the equivalent in terms of antioxidant efficacy of 2.2 g of vitamin E, 1.29 g of trolox, and 5.53 g of β -carotene.

Table 3: Antioxidant activities compared to reference compounds.

* gram of reference compound per gram of product tested

FIG. 4 underlines the divergence in terms of effectiveness between the branch part extract according to the invention and its main metabolites in this test, expressed in millimoles of total antioxidant per gram of product (measurement of the overall antioxidant characteristic of products tested, the highest value corresponds to the best antioxidant efficacy).

Indeed, the inventors have unexpectedly shown that the total antioxidant efficacy of the branch part extract (10.31 mmol / g in antioxidant equivalents) was at least ten times greater than the antioxidant efficacy of its metabolites ( enterodiol (1.07 mmol / g antioxidant equivalents) and enterolactone (1.06 mmol / g antioxidant equivalents)).

2.5. conclusions

Surprisingly, the inventors have demonstrated that the branch part extract according to the invention has a higher antioxidant activity compared to the activities of the reference compounds such as pycnogenol, -tocopherol (Vitamin E), and trolox (analog of Vitamin E), thus demonstrating improved cosmetic efficacy for treating the signs of skin aging and / or for reinforcing the cutaneous barrier.

The inventors have also unexpectedly demonstrated that the branch portion extract according to the invention has superior antioxidant activity compared to of its main metabolites (enterolactone and enterodiol), thus demonstrating improved efficacy for topical administration of the cosmetic composition that avoids the processes of metabolizing the active ingredients.

Claims

A cosmetic composition for combating the signs of skin aging and / or for reinforcing the skin barrier comprising a branch portion extract in a cosmetically acceptable medium, wherein said branch portion extract comprises at least about 50% by weight of polyphenols and less than about 10% by weight of terpenes, based on the total weight of the extract.

The composition of claim 1, wherein said branch portion extract comprises at least about 70%, preferably at least about 90% by weight of polyphenols, based on the total weight of the extract.

3. Composition according to claim 1 or 2, wherein the polyphenols are chosen from hydroxymatairsinol, lariciresinol, secoisolariciresinol, and their epimers.

The composition of any one of claims 1 to 3, wherein said branch portion extract comprises:

about 25% to about 50% by weight of hydroxymatairsinol,

about 5% to about 15% by weight of lariciresinol, and

about 5% to about 15% by weight of secoisolariciresinol,

relative to the total weight of the extract.

A composition according to any one of claims 1 to 4, wherein said branch portion extract is a tree extract selected from Abies alba, Picea abies, Betula pendula, Pinus sylvestris, Abies sibirica, Pinus sibirica, Abies balsamea , Thuja occidentalis, Northern white-cedar, Pinus cembra, Pseudotsuga menziesii, Larix decidua, Picea glauca, Picea mariana, Picea pingens, Abies pectinata, Abies lasiocarpa, Pinus banksiana, Pinus nigra, Pinus pinaster, Pinus resinosa, Larix lariciana, Larix sibirica , Thuja plicata, Fagus sylvatica, Populus alba, Populus nigra, Populus tremula, Populus tremulus, Tsuga hetewphylla, Pinus contorta, Juniperus virginiana, and mixtures thereof.

6. Composition according to any one of claims 1 to 4, wherein said branch portion extract is an extract of a softwood, preferably selected from Abies alba, Picea abies, Pinus sylvestris, Abies sibirica, Pinus sibirica, Abies balsamea, Thuja occidentalis, Northern white-cedar, Pinus cembra, Pseudotsuga menziesii, Larix decidua, Picea glauca, Picea mariana, Picea pingens, Abies pectinata, Abies lasiocarpa, Pinus banksiana, Pinus nigra, Pinus pinaster, Pinus resinosa, Larix lariciana, Larix sibirica, Thuja plicata, Tsuga hetewphylla, Pinus contorta, Juniperus virginiana, and mixtures thereof, and even more preferably selected from Abies alba and / or Picea abies.

The composition of any one of claims 1 to 6, comprising at least about 0.1, preferably at least about 1, at least about 5, at least about 10, and even more preferably at least about 10%. 50% by weight of said branch portion extract relative to the total weight of the composition.

8. Composition according to any one of claims 1 to 7, wherein said composition is a topical or dermatological composition.

9. Composition according to any one of claims 1 to 8, wherein said composition is in the form of a gel, a lotion or a cream.

10. Cosmetic use of the composition according to any one of claims 1 to 9 to combat the signs of skin aging, including the formation of wrinkles, sagging skin and loss of radiance of the complexion, due in particular to the exposure to UV, tobacco and / or pollution and / or to reinforce the skin barrier.

11. Cosmetic process for combating the signs of skin aging, in particular the formation of wrinkles, sagging skin and loss of radiance of the complexion, due in particular to exposure to UV, tobacco and / or pollution and or to reinforce the cutaneous barrier, comprising the topical application to the skin of the composition as defined according to any one of Claims 1 to 9.