WO2016101259A1

WO2016101259A1 - Process for preventing or treating hair graying comprising applying a plant extract comprising (e) -2, 3, 5, 4' -tetrahydroxy stilbene-2-o-glucoside and use thereof

Info

Publication number: WO2016101259A1
Application number: PCT/CN2014/095126
Authority: WO
Inventors: Séverine JEULIN; Xuezhu TAN
Original assignee: L'oreal
Priority date: 2014-12-26
Filing date: 2014-12-26
Publication date: 2016-06-30
Also published as: CN107427437A

Abstract

Providing a process for preventing or treating hair gray comprising a step of applying on hair a composition comprising a plant extract, which comprises (a) at least 5 wt% of (E)-2,3,5,4'-tetrahydroxy stilbene-2-O-glucoside relative to the total weight of the extract, and (b) at least one phenolic compound different from (a), wherein the weight ratio between (a) and the sum of the components (a) and (b) is less than or equal to 0.6.

Description

Process for preventing or treating hair graying comprising applying a plant extract comprising (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside and use thereof

The present invention relates to a process for preventing and/or treating hair graying comprising a step of applying on keratin materials, such as the hair and/or the scalp, a composition comprising a plant extract comprising (a) at least 5％by weight of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (herein after also referred to as THSG) , relative to the total weight of the extract, and (b) at least one phenolic compound different from (a) , wherein the weight ratio between (a) and the sum of the components (a) and (b) is less than or equal to 0.6.

The invention also concerns the use of the plant extract as defined above for preventing or treating hair graying.

Hair whitening or graying is a clear sign of aging, often perceived as distressing for people who are affected when they are still young.

At present, the existing solutions are mainly based on the use of colouring products allowing artificial hair colouring of hair fibers. However, consumers are looking for new products that would not just only treat hair whitening but that would also prevent or delay this, not by artificial means but by acting on the natural process of pigmentation of the hair fibers.

In traditional Chinese medicine, based on the ancient use of natural products, it is mentioned the use of plants to prevent the graying of the hair, even to repigment hair. In particular, the root of Radix Polygoni Multiflori, also known in China as Shou Wu, He Shou Wu or Black Shou Wu, and BSW noted throughout this application, is especially used to prevent hair graying. For information, it is worth noticing that “Shou Wu” means “Black Head” in Chinese.

The reference manual of traditional Chinese medicine (Chinese Pharmacopoeia 2005, published by the State Food and Drug Administration, Beijing, China) specifies that the BSW acts on "the vital essence of the kidney and liver” which are considered to be organs "nourishing the hair. " This means that in this design, BSW can act only through oral intake because the target organs are the kidneys and liver. The expected effect on the strength and vigour of the hair is then a consequence of the action of the BSW on "vital essence of the kidney and liver. "

Since this product is orally administrated, it has the main disadvantage of exposing the person who ingests it to the risk of general adverse effects, as reported in the medical literature, particularly by GJ-H Park., Mann S.P. and MC Ngu, J. Gastroenterol. Hepatol., 2001, 16 (1) : 115-117, and by Cardenas et al. in J. Clin. Gastroenterol, 2006, 40 (7) : 629-632.

Therefore, cosmetic compositions comprising an extract from the root of Radix Polygoni Multiflori were alternatively developed in order to be topically administrated on hair and/or scalp.

For example, the patent application WO 2010/082001 discloses a product for preventing or treating hair graying wherein the extract from the root of Radix Polygoni Multiflori (BSW) is intended to be topically administrated in order to overcome the above mentioned drawback. In particular, this product comprises:

-an extract from the root of Radix Polygoni Multiflori, and

-an active ingredient maintaining or promoting hair growth,

wherein the said extract and the active ingredient promoting hair growth are packed in a single composition or each separately in two separate compositions and wherein the composition comprising the said extract is intended to be topically administrated.

Besides, the extract from Radix Polygoni Multiflori generally contains (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside, or THSG, in an amount of about 4％by weight, relative to the total weight of the said extract.

Unfortunately, current existing products using the said extract are not sufficiently efficient to treat or prevent satisfactorily hair graying.

Therefore, there is a real need to develop new solutions which are able to overcome the drawbacks as previously mentioned in order to treat and/or prevent efficiently hair graying.

The Applicant has discovered, surprisingly, that the use of a plant extract containing at least 5％by weight of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (also known as THSG) , relative to the total weight of the said extract, and one or more phenolic compounds which are different from THSG in a specific weight ratio as defined below, is able to efficiently protect in vitro melanocytes viability after an oxidative stress with peroxide hydrogen, and therefore prevent and/or treat hair graying with success.

In particular, it has been found that the defined concentration by weight of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (THSG) and the specific ratio as described below in the said extract are able to protect more efficiently the melanocytes which are then subjected to an oxidative stress than the current existing products using an extract from the root of Radix Polygoni Multiflori.

In other words, the use of the said plant extract allows preparing cosmetic compositions which are more efficient in terms of prevention and/or treatment of gray hair than the current existing products.

The present invention relates especially to a process for preventing and/or treating hair graying, comprising a step of applying on keratin materials, preferably hair and/or scalp a composition comprising a plant extract comprising:

a) at least 5％by weight of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside, relative to the total weight of the extract, and

b) at least one phenolic compound which is different from a) , wherein the weight ratio of the (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside and the sum of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside a) and the phenolic compound b) is less than or equal to 0.6.

The process of the present invention has the advantage of being efficient and easy to implement.

The invention also deals with the use of the said plant extract for the prevention and/or treatment of gray hair.

In particular, the said plant extract is used to prepare compositions for the prevention and/or treatment of gray hair.

The compositions containing the plant extract of the present invention have the advantage of being stable on storage.

For the purpose of the present invention, the amount of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside is measured using a Waters UPLC system equipped with a UV-Detector (Waters Corporation, US) on a Waters BEH C₁₈ column (50mm×2.1 mm, 1.7μm) .The column is maintained at 25℃, the detection wavelength is 321 nm, the flow rate is 0.5mL/min, and injection volume is 2μL. A gradient elution was used with acetonitrile–water from 25％to 50％acetonitrile for 10 min. No interference with (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside is exhibited by blank injections.

The reference standard and all the samples were dissolved in 50％water-methanol solution (v/v＝1:1) , and sonicated to extract the (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside. Before injection into the UPLC, all the sample solution is filtered by 0.22μm PVDF membrane.

For the purpose of the present invention, the total amount of phenolic compounds, i.e., the sum of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside a) and the phenolic compound b) as mentioned above, is measured according to Folin-Ciocalteau assay. An aliquot (1 ml) of the plant extract according to the present invention or a standard solution of gallic acid (20, 40, 60, 80, and 100 mg/l) is added to a 25 ml volumetric flask, containing 9 ml of distilled deionised water (dd H₂O) . A reagent blank using dd H₂O is also prepared. One millilitre of the Folin-Ciocalteu’s phenol reagent is added to the mixture and shaken. After 5 min, 10 ml of 7％Na₂CO₃ solution is added to the mixture. The solution is diluted to 25 ml with dd H₂O and mixed. After incubation for 90 min at room temperature, the absorbance against the prepared reagent blank is determined at 750 nm with an UV-VIS Spectrophotometer Lambda 5. The data for the total amount of the phenolic compounds of the present invention are expressed as milligrams of gallic acid equivalents (GAE) per 100 grammes dry mass (mg GAE/100 g dw) .

The method is explained in the literatures, such as the article “Total phenolic and total flavonoid contents, antioxidants capacity and biological contaminants in medicinal herbs” , M. Atanassova, et. al., Journal of the University of Chemical Technology and Metallurgy, 46, 1, 2011, 81-88.

For the purposes of the present invention, the term “stable” means that the visual aspect and viscosity of these compositions do not change substantially over time under standard storage test conditions, for example over 12, preferably 24 and even more preferably 30 months at room temperature (25℃) or over 2 months at 45℃ following their manufacture.

The compositions containing the plant extract of the present invention are especially stable on storage over 2 months at 45℃following their manufacture.

According to the present invention, by “keratin materials” we intend to mean the skin and the hair. Skin refers to all the body skin and in particular the scalp. Preferably, the keratin material refers to the hair and the scalp.

Other subjects and characteristics, aspects and advantages of the invention will emerge even more clearly on reading the description and the example that follows.

In the text hereinbelow, and unless otherwise indicated, the limits of a range of values are included in that range, in particular in the expressions “between” and “ranging from …to …” .

Moreover, the expression “at least one” used in the present description is equivalent to the expression “one or more” .

(E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside or THSG (a)

According to the present invention, the plant extract comprises at least 5％by weight of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside, (THSG) relative to the total weight of the extract.

The (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside has the following formula (A) :

Preferably, the (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside corresponds to the following formula (A’ ) :

In a preferred embodiment, the (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside is present in the said plant extract in an amount ranging from 5％to 60％by weight, more preferably in an amount ranging from 10％to 50％by weight, relative to the total weight of the said plant extract.

In a more preferred embodiment, the (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside is present in the said plant extract in an amount ranging from 10％to 30％by weight, relative to the total weight of the said plant extract.

Phenolic compounds (b)

According to the present invention, the plant extract further comprises one or more phenolic compounds (b) different from THSG ( (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside) .

Preferably, the phenolic compound (b) is chosen from Tricin, Catechin, Emodin 1, 6-dimethyl ether, Questin, Citreorosein, Questinol, 2-Acetyl-emodin, 2-Acetyl-emodin-8-O-glucoside, 2-Acetyl-physcion-8-O-glucoside , Gallic acid, 2 , 3 , 5 , 4’ -Tetrahydroxy stilbene 2 , 3-O-diglucoside, (Z) -2 , 3 , 5 , 4’ -Tetrahydroxy stilbene 2 -O-glucoside, N-transferloyltyramine, N-transferloyl-3-methyldopamine, 2-Methoxyl-6-acetyl-7-methyljuglone, Polygonimitin B, Emodin, Chrysophanol, Rhein, Emodin-8-beta-glucoside, Torachrysone-8-O-b-D-glycopyranoside, Emodin-8- (6'-O-malonyl) -glucoside, Physcion-8-O-b-D-glucoside, Physcion-8-O- (6'-O-malonyl) -glucoside, Physcion, Emodin-8-O-b-D-glucoside, Gallic acid ester of torachrysone-8-O-β-D-glucoside, (E) -2, 3, 5, 4' -tetrahydroxystilbene-2-O-beta-D-xyloside, (E) -2, 3, 5, 4'-tetrahydroxystilbene-2-O-beta-D- (6″-O-acetyl) -glucoside, physcion-8-O-beta-D- (6'-O-acetyl) -glucoside, or a mixture thereof.

Ratio between (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside and the total amount of phenolic compounds

According to the present invention, the weight ratio of the (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside and the sum of the total content of phenolic compounds present in the plant extract is less than or equal to 0.6.

In the present invention, the total amount of phenolic compounds represents the sum of the amount of the (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (a) and the phenolic compounds (b) different from (a) .

In a preferred embodiment, the weight ratio between (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (a) and the sum of the amount of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (a) and phenolic compounds b) is preferably less than or equal to 0.55.

In a more preferred embodiment, the weight ratio between (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (a) and the sum of the amount of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (a) and phenolic compounds b) is less than or equal to 0.5.

In a preferred embodiment, the total content of phenolic compounds in the plant extract represents an amount ranging from 5 to 100％by weight, relative to the total weight of the said plant extract.

According to a preferred embodiment, the process is for preventing hair graying.

Preferably, the plant extract used in the process of the present invention comprises:

a) from 5％to 60％by weight of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside, relative to the total weight of the extract, and,

b) at least one phenolic compound which is different from a) ,

wherein the weight ratio of the (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside and the sum of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside and the phenolic compound b) is less than or equal to 0.5.

Preparation of the plant extract

The plant extract used in the composition is preferably obtained by a preparation method comprising the following steps:

(i) pre-treatment of the raw material, preferably the root of Radix Polygoni Multiflori, by using pulveriser crush and putting into an extraction tank,

(ii) extraction for at least two hours, preferably two hours, with 14 times pure water twice, filtering and mixing extraction liquid,

(iii) membrane filtration of the supernatant through ultra-filtration membrane to remove macromolecules,

(iv) preparation of concentrates from the filtrate obtained in step (iii) at a temperature less than or equal to 70℃ and under pressure ranging from 0.06 to 0.07 MPa,

(v) centrifugation in order to remove the insoluble materials,

(vi) purification with resin absorption and use of ethanol and water for elution,

(vii) preparation of concentrates from the eluate obtained in step (vi) at a temperature less than or equal to 70℃ and under pressure ranging from 0.06 to 0.07 MPa,

(viii) spray drying,

(ix) sieving, mixing and packaging,

The plant extract used in the composition of the process according to the invention is preferably an extract from the root of Radix Polygoni Multiflori.

The process for producing the extract mentioned above is disclosed in the Chinese patent ZL 201310313435.7.

Compositions containing the plant extract

According to the present invention, the plant extract is soluble in the composition used in the process.

For the purposes of the present invention, the term “soluble” means that the weight solubility of the plant extract is higher than or equal to 1％in the composition.

The compositions containing the plant extract may further contain one or more surfactants.

In particular, the surfactant (s) are chosen from anionic, amphoteric, zwitterionic, cationic and nonionic surfactants, and preferentially nonionic surfactants and cationic surfactants.

The compositions used in the process of the present invention may also comprise additional components.

The additional components may, for example, be chosen from thickening polymers, anionic, nonionic, amphoteric or zwitterionic polymers or mixtures thereof, oils, antioxidants, sequestrants, preservatives, fragrances, dispersants, ceramides, stabilizers and opacifiers.

Of course, a person skilled in the art will be sure to choose this or these optional additional compound (s) so that the advantageous properties intrinsically linked to the method in accordance with the invention are not, or not substantially, impaired by the envisaged addition (s) .

The above additional components may in general be present in an amount, for each of them, between 0 and 20％by weight relative to the total weight of each composition.

The present invention also deals with the use of the plant extract as defined above for preventing and/or treating hair graying, preferably for preventing hair graying.

The present invention relates to the use of the plant extract as defined above for protecting the human melanocyte viability after an oxidative stress.

The following examples serve to illustrate the invention without being limiting.

EXAMPLES

Example 1:

The following example deals with the protective capacity on normal human melanocytes viability after an oxidative stress performed with hydrogen peroxide.

a) Procedure

Normal human melanocytes were treated with the compositions disclosed below or with solvents of BSW such as DMSO and N-acetyl-cystein. After a day and a half, the melanocytes were subjected to a dose dependent oxidative stress with increasing concentrations of hydrogen peroxide H₂O₂.

Melanocyte viability was measured with an alamar blue test, according to the UptiBlue Viable Cell Counting Assay, using Uptiblue Viable Cell Counting Reagent provided by the company Interchim. The method incorporates a fluorometric/colorimetric growth indicator based on detection of metabolic activity. Specifically, the system incorporates an oxidation-reduction (REDOX) indicator that fluoresces in response to chemical reduction of growth medium resulting from cell growth.

To measure melanocyte viability, cell culture medium is removed and replace by a cell culture medium containing 10％of the uptiblue redox indicator. Cell plates are incubated during 3h at 37℃in a 5％CO₂ incubator. Then fluorescence is measured at 590 nm by using a fluorimeter (victor III, perkin Elmer) . The fluorescence intensity is proportional to the number of viable cells. N-acetyl-cystein was assessed as a positive reference.

For each treatment, a local regression, or loess as noted throughout this example, curve was calculated based on the whole viability data as a function of H₂O₂ stress condition, and was drawn with the confidence interval at 95％ (noted as CI95 throughout this example) .

We can conclude about a protective effect of active agent when “the active agent viability regression curve” decreased significantly slower than the “solvent viability regression curve” . The loess regression curves + CI95 allow determining the range of H₂O₂ concentration where the tested active agent protects melanocyte viability. The intensity of the protection is given by the area between the active agent and its solvent curves with normalized values as a function of N-acetyl-cystein (positive reference) .

b) Tested plant extracts

The plant extract A represents a plant extract according to the present invention which comprises:

-19.1％by weight of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (THSG) a) relative to the total weight of the plant extract,

-21.9％by weight of phenolic compounds b) relative to the total weight of the plant extract,

wherein the ratio between (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (a) and the total phenolic compounds present in the extract corresponds to 0.47.

The plant extract B comprises:

-15.9％by weight of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (THSG) a) relative to the total weight of the plant extract,

-10.2％by weight of phenolic compounds b) relative to the total weight of the plant extract,

wherein the ratio between (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (a) and the total phenolic compounds present in the extract corresponds to 0.61.

The plant extract C comprises:

-4.3％by weight of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (THSG) a) relative to the total weight of the plant extract,

-7.2％by weight of phenolic compounds b) relative to the total weight of the plant extract,

wherein the ratio between (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside (a) and the total phenolic compounds present in the extract corresponds to 0.37.

The plant extracts A, B and C were also compared against DMSO and N-acetyl-cystein. The latter represents the positive reference.

c) Results

The results are given in the table below:

All the contents were measured based on the methods disclosed in the description.

According to this table, the plant extract A according to the invention is able to protect melanocyte viability after oxidative stress more efficiently than the plant extracts B and C.

Example 2

The following composition was prepared with the ingredients listed in the table below. The quantities were expressed in weight percentage unless otherwise is mentioned.

The composition A is stable on storage over two months at 45℃.

Claims

Process for preventing and/or treating hair graying, comprising a step of applying on keratin materials, preferably hair and/or scalp a composition comprising a plant extract comprising:

a)at least 5％by weight of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside, relative to the total weight of the extract, and

b)at least one phenolic compound which is different from a) ,

wherein the weight ratio of the (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside a) and the sum of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside a) and the phenolic compound b) i s less than or equal to 0.6.
The process of claim 1, characterized in that the (E) -2,3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside corresponds to the following formula (A’ )
The process according to claim 1 or 2, characterized in that the(E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside is present in an amount ranging from 5％to 60％by weight, preferably from 10％to 50％by weight, relative to the total weight of the said extract.
The process of any one of the claims 1 to 3, characterized in that the phenolic compound (b) is chosen from Tricin, Catechin, Emodin 1, 6-dimethyl ether, Questin, Citreorosein, Questinol, 2- Acetyl-emodin, 2-Acetyl-emodin-8-O-glucoside, 2-Acetyl-physcion-8-O-glucoside, Gallic acid, 2, 3, 5, 4’ -Tetrahydroxy stilbene 2, 3-O-diglucoside, (Z) -2, 3, 5, 4’ -Tetrahydroxy stilbene 2-O-glucoside, N-transferloyltyramine, N-transferloyl-3-methyldopamine, 2-Methoxyl-6-acetyl-7-methyljuglone, Polygonimitin B, Emodin, Chrysophanol, Rhein, Emodin-8-beta-glucoside, Torachrysone-8-O-b-D-glycopyranoside, Emodin-8- (6'-O-malonyl) -glucoside, Physcion-8-O-b-D-glucoside, Physcion-8-O- (6'-O-malonyl) -glucoside, Physcion, Emodin-8-O-b-D-glucoside, Gallic acid ester of torachrysone-8-O-β-D-glucoside, (E) -2, 3, 5, 4'-tetrahydroxystilbene-2-O-beta-D-xyloside, (E)-2, 3, 5, 4'-tetrahydroxystilbene-2-O-beta-D- (6″-O-acetyl) -glucoside, physcion-8-O-beta-D- (6'-O-acetyl) -glucoside, or a mixture thereof.
The process according to any one of the claims 1 to 4, characterized in that the phenolic compound is present in an amount ranging from 3％to 95％by weight, relative to the total weight of the extract.
The process according to any one of the preceding claims 1 to 5, characterized in that the ratio between the (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside and the total amount of (E) -2,3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside and phenolic compound b) is less than or equal to 0.55, more preferably less than or equal to 0.5.
The process according to any one of the preceding claims 1 to 6, characterized in that plant extract is a Polygonum multiflorum root extract.
The process according to any one of the preceding claims 1 to 7, wherein hair graying is prevented.
Process for preventing and/or treating hair graying, comprising a step of applying on hair and/or on scalp a composition comprising a plant extract comprising:

a)at least from 5％to 60％by weight of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside, relative to the total weight of the extract, and

b)at least one phenolic compound which is different from a) ,

wherein the weight ratio of the (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside a) and the sum of (E) -2, 3, 5, 4’ -tetrahydroxy stilbene-2-O-glucoside a) and the phenolic compound b) i s less than or equal to 0.5.
Use of a plant extract as defined in any of the preceding claims 1 to 8 for preventing and/or treating hair graying.
Use according to claim 10 for protecting the human melanocyte viability after an oxidative stress.