WO2007094533A1

WO2007094533A1 - Composition for inhibiting collagen degradation and promoting collagen synthesis comprising emodin

Info

Publication number: WO2007094533A1
Application number: PCT/KR2006/001550
Authority: WO
Inventors: Deok Hoon Park; Jong Sung Lee; Eun Sun Jung; Chang Gu Hyun; Seong Taek Hong
Original assignee: Biospectrum, Inc.
Priority date: 2006-02-17
Filing date: 2006-04-25
Publication date: 2007-08-23
Also published as: KR20070083302A

Abstract

Disclosed is a composition, comprising emodin, for inhibiting collagen degradation and promoting collagen synthesis. The composition stimulates cell regeneration by promoting the synthesis of collagen by normal fibroblasts, alleviates wrinkles, and imparts the skin with elasticity. Also, the composition can be used as a preparation for external use for skin, such as cosmetics.

Description

COMPOSITION FOR INHIBITING COLLAGEN DEGRADATION AND PROMOTING COLLAGEN SYNTHESIS

COMPRISING EMODIN

Technical Field

[1] The present invention relates to a composition comprising emodin as an effective ingredient for the alleviation of wrinkles.

Background Art [2] The amount of collagen synthesis and the amount of expression and activity of collagenase, a collagen degradation enzyme that reduces collagen content, are highly implicated in the formation of wrinkles. [3] Collagen, a high molecular weight substance present in the dermis, is known to be one of the main components responsible for skin elasticity. Collagen degradation is greatly promoted by natural aging and exterior environmental factors such as stress. [4] Thus, many approaches are being explored to find substances that promote collagen synthesis and inhibit collagenase activity as a way of alleviating wrinkles. [5] Emodin is an anthraquinone derivative isolated from the rhizomes of Rheum palmatum, which is traditionally used as a laxative. Emodin is reported to have various biological activities including immunosuppressive effects, liver protective effects, and anticancer effects. Emodin has the IUPAC name

3-methyl-l,6,8-trihydroxyanthraquinone, and is represented by the following structural formula: [6]

[7] Leading to the present invention, thorough and intensive research into the physiological activity of emodin, conducted by the present inventor, resulted in the finding that emodin can suppress collagen degradation and promote collagen synthesis, thereby being able to alleviate skin wrinkles in practice. Disclosure of Invention Technical Solution

[8] An object of the invention is to provide a composition comprising emodin that inhibits collagen degradation and promotes collagen synthesis.

[9] Another object of the invention is to provide a preparation for external application to the skin, comprising the composition.

[10] A further object of the invention is to provide a cosmetic comprising the composition. Brief Description of the Drawings

[11] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[12] FIG. 1 shows the effect of emodin on the promotion of collagen synthesis. (RA: retinoic acid, Ed:emodin);

[13] FIG. 2 shows the effect of emodin on the induction of cell proliferation.

(FGF-2:fetal growth factor-2, Ed:emodin);

[14] FIG. 3 shows the inhibitory effect of emodin on collagenase activity (Ed: emodin);

[15] FIG. 4 shows the mechanism by which emodin inhibits collagenase activity (Ed: emodin, TNF alpha:tumor necrosis factor alpha); and

[16] FIG. 5 shows the effect of emodin on the phosphorylation of p42/22 mapk, JNK, and p38mapk (Ed:emodin). Best Mode for Carrying Out the Invention

[17] In accordance with an aspect thereof, the present invention relates to a composition comprising emodin which inhibits collagen degradation and promotes collagen synthesis.

[18] The present inventor has determined that the biological activity of emodin is as given below.

[19] Emodin promotes collagen synthesis. Emodin has been found to have effects of promoting collagen synthesis in a concentration-dependent manner, as measured in human normal fibroblasts (Pacific) treated with emodin.

[20] Emodin proliferates cells. The results of MTT assay measurement on cell proliferation of emodin-treated human normal fibroblasts in serum-free media led to the conclusion that emodin induces the proliferation of normal human fibroblasts in a concentration-dependent manner.

[21] Emodin inhibits collagen degradation. Emodin has collagen degradation inhibitory activity which is attributable to the mechanism of inhibiting the activation and expression of collagenase, an enzyme that decomposes collagen. Emodin inhibits the AP-I promoter of collagenase (MMP-I). The inhibitory activity of emodin on the AP- 1 promoter was found to result from the inhibitory activity of emodin on JNK and p42/44mapk. [22] As mentioned above, emodin has effects of alleviating wrinkles since it has activities of inhibiting collagen degradation and promoting collagen synthesis within the cells. In fact, as examined in the examples of the present invention, the result of measurement on the effects of skin elasticity on wrinkle alleviation showed that a test subject treated with a cream comprising emodin had far greater skin elasticity than a test subject treated with a control devoid of emodin. In addition, the skin elasticity was observed to improve as the concentration of emodin in the cream increased.

[23] Emodin is contained in an amount of 0.001 to 20 w/w%, and preferably in an amount of 0.01 to 5 w/w%, based on the total weight of the composition. The present invention can comprise additional active ingredients having wrinkle alleviation effects, along with the aforementioned emodin, provided that they don't have an inhibitory effect on the alleviation of wrinkles.

[24] The composition of the present invention may be applied to medical supplies, food products, and cosmetics for the treatment of wrinkles, and can be administered both orally (for internal use) and non-orally (for external use). The composition of the present invention can be administered orally, in the form of medicine for internal use or food products, and non-orally, in the form of cosmetics and medicine for external use, and can be mixed with typical carriers or additives known in the field.

[25] In another aspect, the present invention relates to a preparation for external use for skin comprising the present composition. Emodin was found to be a safe substance for human skin and acceptable for preparations for external use on skin, as proved by a cumulative skin irritation test. The form of the composition is not particularly limited. For example, it includes powders, gels, ointments, creams, liquids, and aerosols.

[26] In a preferred embodiment, one of the applicable types of preparations for external use on skin is cosmetics. In cosmetics, other components in addition to emodin can be used added depending on the type and purpose of the cosmetics. The cosmetic of the present invention can be blended with purified water, oils, surfactants, humectants, higher alcohol, chelating agents, colorants, fatty acids, antioxidants, preservatives, wax, pH adjusters, and perfumes.

[27] As for oils, they may be mineral oil, cyclomethicone, squalene, octyldodecyl myristate, olive oil, macadamia nut oil, glyceryl octanoate, castor oil, ethylhexyl isononanoate, dimethicone, cyclopentasiloxane, or sunflower seed oil. Examples of the surfactants include sorbitan sesquioleate, polysorbate 60, glyceryl stearate, lipophilic glyceryl stearate, sorbitan oleate, sorbitan stearate, DEA-cetyl phosphate, sorbitan stearate/sucrose cocoate, glyceryl stearate/polyethylene glycol- 100 stearate, ceteareth-6 olivate, arachidyl alcohol/behenyl alcohol/arachidyl glucoside, polypropylene glycol- 26-buteth-26/polyethylene glycol-40, and hydrogenated castor oil. Glycerin, sorbitol, propylene glycol, butylene glycol, hexylene glycol, diglycerin, betaine, glycereth-26, or methylgluceth-20 can be used as humectants. Cetyl alcohol, stearyl alcohol, octyl dodecanol, and isostearyl alcohol can be used as higher alcohols. Xanthan Gum, carbomer, magnesium aluminium silicate, cellulose gum, and dextrin palmitate can be used as thickeners. Disodium EDTA and tetrasodium EDTA can be used as chelating agents. Blue No. 1, Red No. 40, and Yellow No. 4 and 5 can be used as colorants. Stearic acid, myristic acid, palmitic acid, isostearic acid, and lauric acid can be used as fatty acids. Tocopheryl acetate and butylated hydroxy toluene can be used as antioxidants. Methyl paraben, butyl paraben, propyl paraben, phenoxyethanol, imida- zolidinyl urea, and chlorphenesin can be used as preservatives. Carnauba wax, candelilla wax, beeswax, and spermaceti can be used as waxes. Triethanolamine and citric acid can be used as pH adjusters. The perfumes useful in the cosmetics may be natural or synthetic.

[28] The form of the cosmetics produced as the composition of the present invention is not particularly limited. For example, it can include nutrient creams, astringents, toners, lotions, essences, nutrient gels, and massage creams. Mode for the Invention

[29] A better understanding of the present invention may be obtained through the following examples which are set forth to illustrate, but are not to be construed as the limit of the present invention.

[30]

[31] EXAMPLE 1 : Effects of Emodin on Promoting Collagen Synthesis

[32]

[33] Human normal fibroblasts (Pacific) were inoculated at a density of 2x10 cells/well in DMEM medium in 6-well microplates, and incubated at 37⁰C under 5% CO for 24 hrs. After removing the culture medium, cells were treated with emodin in varying amounts of 0.025 ppm, 0.25 ppm, 1.25 ppm, 2.5 ppm, and 5.0 ppm in DMEM supplemented with 0.05% FBS, and incubated again for 24 hrs. Thereafter, cell cultures were collected and samples were taken.

[34] The extent of collagen synthesis was determined by measuring the amount of procollagen type I C-peptide (PICP) using Procollagen Type I C-peptide EIA kit (MKlOl, Takara, Kyoto, Japan). After diluting a standard solution contained in the collagen kit, absorbance at 450nm was measured and a standard concentration curve was composed. 100 D of a POD-labeled antibody solution was added to each well, followed by the addition of 20 D of the supernatant of each sample and 20 D of each concentration of the standard solution series thereto. The absorbance of mixtures was measured at 37⁰C. This assay was conducted in duplicate, and the average value was calculated. Accurate sample concentrations of PICP could be determined by comparing their specific absorbances with those obtained for the standards plotted on a standard curve, and represented as ng/2xlθ cells.

[35]

[36] As a result, emodin was found to increase the synthesis of collagen 1 in human normal fibroblasts. The result is shown in FIG. 1. Retinoic acid in an amount of 1 microM(μM) was used as a positive control.

[37]

[38] EXAMPLE 2: Effects of Emodin on Cell Proliferation

[39]

[40] In order to assay the effects of emodin on cell proliferation, human normal fibroblasts (Pacific) were treated with emodin in varying amounts of 0.025 ppm, 0.25 ppm, 1.25 ppm, 2.5 ppm, and 5.0 ppm, and cultured in serum-free media before analysis by MTT (3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. When ring-opened by the mitochondrial respiratory enzymes of viable cells, MTT is turned from a yellow tetrazole to a dark blue formazan. Since this reduction does not take place in dead cells, the amount of dark blue formazan produced by cells is used for the measurement of the number of viable cells.

[41] The data obtained in the MTT assay demonstrate that emodin induces the proliferation of human normal fibroblasts in a concentration-dependent manner (FIG. 2).

[42]

[43] EXAMPLE 3: Effects of Emodin on the Inhibition of Collagenase Activity

[44]

[45] Human normal fibroblasts (Pacific) were inoculated at a density of 2x10 cells/well in DMEM medium in 6-well microplates, and incubated at 37⁰C under 5% CO for 24 hrs. After removing the culture medium, serum starvation was induced for 16 hrs in DMEM medium supplemented with 0.05% FBS. The cells were treated with TNF- alpha (20ng/ml), alone or in combination with emodin in varying amounts of 0.025 ppm, 0.25 ppm, 1.25 ppm, 2.5 ppm, and 5.0 ppm for 24 hrs. After that, cells were collected and samples were taken.

[46] As a method of measuring the activity of collagenase, an enzyme that decomposes collagen, a collagenase antibody was used. A Type 1 collagenase assay kit (Amersham Biosciences, RPN2629) was used, and the absorbance was measured using an ELISA reader. The measured average values were represented as average ± standard deviation. A T-test with SPSS/PC+ was conducted to determine significance, and the result is shown in FIG. 3.

[47]

[48] EXAMPLE 4: Effects of Emodin on the Inhibition of AP-I Promoter Activity

[49] [50] A test was conducted to examine the inhibitory mechanism of emodin, which regulates the activity of collagenase(MMP-l), an enzyme that breaks down collagen. It has been reported that the AP-I element is present in a promoter that plays a critical role in the expression of collagenase(MMP-l). Based on this, the AP-I promoter reporter test was conducted to find out whether emodin inhibits collagenase activity by inhibiting the activity of the AP- 1 promoter. Transformation was induced by inserting the AP-I reporter DNA into human normal fibroblast cells using Superfect. After 24 hrs of transformation, cells were treated with TNF-alpha in an amount of 10 ng/ml and emodin. 16 hrs after the treatment, cells were collected and measured for luminescence at 450nm using a luminometer (Berthold, Germany) (reference: Planta medica 2005; 71:338-343).

[51] As shown in FIG. 4, it was found that the activity of the AP-I promoter induced by

TNF alpha, and was greatly decreased by emodin in a concentration-dependant manner. This result indicates that the inhibitory activity of emodin on the activation and expression of collagenase (MMP-I) results from the inhibition of the AP-I promoter.

[52]

[53] EXAMPLE 5: Effects of Emodin on the Inhibition of MAPK Phosphorylation

[54]

[55] As is apparent from the data of FIG. 4, emodin inhibits TNF alpha-induced activation of the AP- 1 promoter. In order to find out whether this inhibition activity of emodin is related with the protein kinase which induces AP-I promoter activation, western blotting was conducted. First, human normal fibroblast cells were treated with TNF alpha, both alone and in combination with emodin, and were incubated for 4 hrs. Thereafter, cells were collected and Western blotting against phospho-MAPK, phospho-JNK, and phospho-p38mapk (Cell signaling technology) was conducted. As shown in FIG 5, emodin has inhibitory activity on the phosphorylation of JNK and p42/44mapk, but not on the phosphorylation of p38mapk. These results imply that the inhibitory activity of emodin against the AP-I promoter is based on inhibiting the activation of JNK and p42/44mapk. Therefore, the inhibitory activity of emodin is mainly attributable to inhibiting the activation of JNK and p42/44mapk (FIG. 5).

[56]

[57] PREPARATION EXAMPLE: Cosmetic Composition Comprising Emodin

[58]

[59] A. Cream comprising emodin

[60] A nutrient cream comprising emodin was prepared as indicated in Table 1 below.

Aqueous phases including purified water, triethanolamine and propylene glycol, and oil phases including fatty acids, oil components, emulsifiers, and preservatives were heated to 70⁰C and mixed for emulsification. After completion of the emulsification, the emulsion was cooled to 45°C. Emodin and perfumes were added and dispersed before cooling to 30⁰C.

[61] [62] Table 1 Components and Contents of Nutrition Cream Comprising Emodin

[63] [64] B. Cosmetic water comprising emodin [65] a) Skin softener [66] A skin softener comprising emodin was prepared as indicated in Table 2, below. Purified water was added to the water-based components and the aqueous mixture was dissolved at room temperature. Separately, emodin, oil components, emulsifiers, preservatives, and perfumes were dissolved at room temperature, and were then added to the aqueous mixture, followed by the filtration of the admixture.

[67] [68] Table 2 Components and Contents of Skin Softener Comprising Emodin

[69] [70] b) Astringent [71] An astringent comprising emodin was prepared as indicated in Table 3 below. Purified water was added to water-based components and the aqueous mixture was dissolved at room temperature. Separately, emodin, oil components, emulsifiers, preservatives, and perfumes were added to ethanol and the alcohol-based mixture was dissolved at room temperature. The alcohol-based mixture was mixed with the aqueous mixture, followed by the filtration of the admixture.

[72] [73] Table 3 Components and Contents of Astringent Comprising Emodin

[74] [75] C. Lotion [76] A lotion comprising emodin was prepared as indicated in Table 4, below. Aqueous phases including purified water, triethanolamine and butylene glycol, and oils phases, including fatty acids, oil components, emulsifiers and preservatives, were heated to 7O⁰C and mixed to form an emulsion. After completion of the emulsification, 2% xanthan gum liquid, serving as a hydrophilic thickener, was added to the emulsion in an amount of 0.05 wt% based on the total weight of the solution. This solution was cooled to 45⁰C and then added with emodin, perfumes, and colorants before cooling again to 3O⁰C.

[77] [78] Table 4 Components and Contents of Lotion Comprising Emodin

[79] [80] D. Gel [81] A gel comprising emodin was prepared as indicated in Table 5, below. [82] [83] Table 5 Components and Contents of Gel Comprising Emodin

[84] [85] E. Essence [86] An essence comprising emodin was prepared as indicated in Table 6, below. The thickener was added to purified water with slow stirring until it was dispersed homogeneously. The water-based components were mixed to obtain an aqueous phase. The emulsifiers, skin softeners, perfumes and preservatives were added to ethanol and di ssolved. This alcohol phase was added to the aqueous phase with stirring, followed by the addition of an alkali agent, and finally emodin and colorants.

[87] [88] Table 6 Components and Contents of Essence Comprising Emodin

[89] [90] COMPARATIVE PREPARATION EXAMPLE: Cream Comprising Purified Water

[91] [92] A cream was prepared in a manner similar to that of Preparation Example A, with the exception that purified water was used instead of emodin, and its composition is given in Table 7, below.

[93] [94] Table 7

[95] [96] EXAMPLE 6: Safety Test of Emodin on Human Skin [97] [98] In order to find out whether emodin is safe for use on human skin, a skin safety test was conducted. Suitable for this was a cumulative skin irritation test.

[99] Squalene-based preparations comprising emodin in amounts of 1%, 5%, and 10% were applied in patches 9 times to the upper arms of 30 healthy adults once every other day for a total time period of 24 hours. This 24-hour cumulative patch test was conducted to determine whether emodin irritates the skin or not.

[100] The Finn chamber (Epitest Ltd, Finland) was chosen as the patching method. The above preparation for external use on the skin was dropped into each chamber in an amount of 15 D, and a patch was applied. The level of reaction on the skin for each test was scored using Formula 1, below, and the result is shown in Table 8, below.

[101] [102] [Formula 1] [103]

Rxn. Index x Rxn Level

Avg. Rxn. Level = 100

No. of Test Subjects x Max. Points (4 points) No. of Test (9 times)

[104] [105] Points were marked in accordance with reaction level, for example, ± for 1 point, + for 2 points, and ++ for four points. The composition can be considered safe if the average reaction level is below 3.

[106] [107] [Table 8] [108]

[109] [HO] In the Table 8, the number of people is 2 for ±, zero for +, zero for ++, in Tests 1, 2, and 3, and the average reaction level was calculated to be 0.18. As the average reaction level is below 3, emodin was proven to be a safe substance for human skin, not showing any significant cumulative irritation.

[111] [112] EXAMPLE 7: Evaluation of Effects of Cosmetics Comprising Emodin on the Alleviation of Wrinkles

[113] [114] The effects of a cosmetic material comprising emodin on the alleviation of wrinkles were measured in a clinical demonstration. The nutrient creams prepared in Preparation Example A (nutrient creams comprising emodin in amounts of 1%, 2%, and 5%, respectively) and Comparative Preparation Example (a nutrient cream comprising purified water) were used.

[115] The effects of wrinkle alleviation were evaluated by measuring the changes in the elasticity of the skin. Measurements were conducted on 30 healthy female test subjects (aged 25 to 35) in a stable environment of temperature ranging from 24⁰C to 26⁰C and humidity ranging from 38% to 40%. After 3 types of nutrient creams of Preparation Example A and the nutrient cream of Comparative Preparation Example were applied to the facial skin of test subjects twice a day for 3 months, the elasticity was measured using a Cutometer SEM 474. Relative grades were set forth for skin elasticity within a range from zero for no elasticity to 5 for the highest elasticity measured, and the results are shown Table 9, below.

[116] [117] [Table 9] [118]

[119] [120] As shown in Table 9, the preparation example A of the present invention showed significantly greater effects on the alleviation of wrinkles compared to the comparative preparation example, and skin elasticity improved as the concentration of emodin increased. Industrial Applicability

[121] Taken together, the results obtained in the clinical demonstrations demonstrate that emodin has significant effects on the alleviation of wrinkles and is applicable as a new material for wrinkle alleviation, with little irritation of the skin. It is expected that the application of emodin can contribute to the development of the cosmetics industry by reducing the importation of foreign materials and increasing the competitiveness of domestic materials.

[122] Although the preferred embodiment(s) of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

[1] A composition for inhibiting collagen degradation and promoting collagen synthesis, comprising emodin.

[2] The composition as set forth in claim 1, wherein the composition has an effect of alleviating wrinkles.

[3] The composition as set forth in claim 1, wherein the composition comprises emodin in an amount of 0.001 to 20.0 w/w%, based on total weight of the composition.

[4] A preparation for external use for skin, comprising the composition of claim 1.

[5] A preparation for external use for skin as set forth in claim 4, wherein the composition is in a form of a powder, gel, ointment, cream, liquid or aerosol.

[6] A cosmetic comprising the composition of claim 1.

[7] The cosmetic as set forth in claim 6, wherein the cosmetic is in the form of a nutrient cream, an astringent, a skin softener, a lotion, an essence, a nutrient gel, or a massage cream.