External preparation for preventing and / or improving skin yellowing

Abstract

To prevent and / or improve xanthoderma.SOLUTION: The present invention discloses topical preparations and / or cosmetics for preventing and / or improving xanthoderma, containing αhydroxy acid.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an external preparation for preventing and / or improving skin yellowing. [Background technology]

[0002] Glycation refers to the reaction in which excess sugar in the body binds with proteins to produce advanced glycation end-products (AGEs), which are involved in diabetic complications, Alzheimer's disease, arteriosclerosis, etc. From a beauty perspective, the accumulation of AGEs causes discoloration and cross-linking of proteins such as collagen in the skin, leading to reduced elasticity of the skin, wrinkles, and yellowing.

[0003] Regarding dull skin, cosmetics such as peel-off packs that improve skin softness and transparency by peeling off the stratum corneum are already on the market, but there are almost no cosmetics that claim to prevent the "yellowing" of the skin, including the stratum corneum. It has been reported that one cause of skin yellowing is the glycation of proteins in the epidermis, such as the stratum corneum (Non-Patent Document 1), but there are almost no known substances that prevent and / or improve skin yellowing caused by glycation. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Ogura et al., J. Dermatol. Sci. 64:45-52, 2011 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide an external preparation that prevents and / or improves skin yellowing, which causes yellowing of the skin and the like. [Means for solving the problem]

[0006] As a result of intensive research aimed at solving the above problems, the inventors unexpectedly discovered that alpha hydroxy acid (AHA) suppresses both the fluorescence intensity and absorbance of glycation products, and thus completed the present invention.

[0007] The present invention encompasses the embodiments described below.

[0008] Item 1. An external preparation for preventing and / or improving skin yellowing, which contains alpha hydroxy acids including lactic acid, malic acid, and citric acid (excluding the improving agent in (I) and the external skin preparation in (II) below). (I) A skin color improving agent containing an advanced glycation end product decomposer which is the following (bi), (b-ii), or (b-iii): (bi) at least one member selected from the group consisting of unsaturated fatty acids, and pharma- ceutically acceptable salts thereof, pharma-ceutically acceptable glycerides thereof, pharma-ceutically acceptable esters thereof, and pharma-ceutically acceptable amides thereof; (b-ii) A vegetable oil containing at least one selected from the group consisting of unsaturated fatty acids and pharma- ceutically acceptable derivatives thereof. (b-iii) Plant extracts with AGEs decomposition effect (II) A skin topical preparation for reducing yellowing of the skin, comprising hesperetin and / or glycosyl hesperetin as an active ingredient.

[0010] term 2 The concentration of α-hydroxy acid in the topical preparation for preventing and / or improving skin yellowing is 0.001 to 5% by mass. 1 2. An external preparation for preventing and / or improving skin yellowing according to claim 1.

[0011] term 3 Cosmetics for preventing and / or improving skin yellowing, containing alpha hydroxy acids including lactic acid, malic acid, and citric acid (excluding the improvement agents (I) and topical skin preparations (II) below). (I) A skin color improving agent containing an advanced glycation end product decomposer which is the following (bi), (b-ii), or (b-iii): (bi) at least one member selected from the group consisting of unsaturated fatty acids, and pharma- ceutically acceptable salts thereof, pharma-ceutically acceptable glycerides thereof, pharma-ceutically acceptable esters thereof, and pharma-ceutically acceptable amides thereof; (b-ii) A vegetable oil containing at least one selected from the group consisting of unsaturated fatty acids and pharma- ceutically acceptable derivatives thereof. (b-iii) Plant extracts with AGEs decomposition effect (II) A skin topical preparation for reducing yellowing of the skin, comprising hesperetin and / or glycosyl hesperetin as an active ingredient.

[0013] term 4 The concentration of α-hydroxy acid in the cosmetic composition for improving skin yellowing is 0.001 to 5% by mass. 3 A cosmetic composition for preventing and / or improving skin yellowing as described above. Effect of the Invention

[0014] According to the present invention, yellowing of the skin can be effectively prevented and / or improved. [Brief description of the drawings]

[0015] [Figure 1] Effect of aminoguanidine (AG) on the glycation reaction of bovine serum albumin (BSA) and the glycation intermediate glyoxal (GO). (A) Fluorescence intensity of advanced glycation end products (AGE) in each sample, (B) absorbance of AGE in each sample, (C) photographs of each sample in Figure 1. [Diagram 2] Effect of lactic acid on the glycation reaction of BSA and glyoxal (GO). (A) Photographs of samples with various concentrations of lactic acid, (B) absorbance of AGE, and (C) fluorescence intensity of AGE. [Diagram 3]Effect of various hydroxy acids (0.1%) on the glycation reaction of BSA and glyoxal (GO). (A) Absorbance of AGE, (B) Fluorescence intensity of AGE. [Figure 4] Effect of L-ascorbic acid (vitamin C) on the glycation reaction of BSA and glyoxal (GO). (A) Photographs of samples with various concentrations of L-ascorbic acid, (B) absorbance of AGE (ND: not measurable due to gelation), (C) fluorescence intensity of AGE. [Diagram 5] Effect of Trolox (a water-soluble analogue of vitamin E) on the glycation reaction of BSA and glyoxal (GO). (A) Photographs of samples with various concentrations of Trolox (a water-soluble analogue of vitamin E), (B) absorbance of AGE, and (C) fluorescence intensity of AGE. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present invention relates to an external preparation or cosmetic that prevents and / or improves yellowing of the skin, including the stratum corneum. "Prevention" refers to the action of preventing yellowing of skin that has not yet been yellowed, and "improvement" includes the action of reducing yellowing of skin that has already yellowed, inhibiting the progression of further yellowing, and reducing yellowing along with skin turnover (metabolism). "Prevention and / or improvement" refers to prevention, improvement, or both prevention and improvement.

[0017] The topical agent and cosmetic for preventing and / or improving skin yellowing according to the embodiment of the present invention contain an α-hydroxy acid. The α-hydroxy acid acts as an active ingredient for preventing or suppressing skin yellowing. The α-hydroxy acid refers to a hydroxy acid, which is a compound having both a carboxy group and a hydroxy group, in which a hydroxy group is also bonded to the carbon atom to which the carboxy group is bonded.

[0018] The α-hydroxy acid is not particularly limited, but from the viewpoint of suppressing both the fluorescence intensity and absorbance derived from AGE, the α-hydroxy acid is preferably at least one selected from the group consisting of lactic acid, malic acid, citric acid, tartaric acid, and glycolic acid. These α-hydroxy acids are commercially available. Lactic acid is preferred from the viewpoints of suppressing both the fluorescence intensity and absorbance derived from AGE and of being less likely to cause gelation of the reacting protein. Citric acid and glycolic acid are preferred from the viewpoint of the strength of the anti-glycation effect.

[0019] The concentration of the α-hydroxy acid in the topical agent and cosmetic for preventing and / or improving skin yellowing is not particularly limited, but from the viewpoint of preventing skin yellowing, it is preferably 0.001 to 5 mass%, more preferably 0.01 to 2 mass%, and even more preferably 0.05 to 1 mass%.

[0020] The concentration of α-hydroxy acid in the topical agent and cosmetic for preventing and / or improving skin yellowing is not particularly limited, but from the viewpoint of preventing and / or improving skin yellowing, it is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.05% by mass or more. In addition, the concentration of α-hydroxy acid in the topical agent and cosmetic for preventing and / or improving skin yellowing is not particularly limited, but from the viewpoint of preventing and / or improving skin yellowing, it is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 2% by mass or less.

[0021] When the α-hydroxy acid contains lactic acid, the concentration of lactic acid in the topical agent and cosmetic for preventing and / or improving skin yellowing is preferably 0.0001 to 3 mass %, more preferably 0.01 to 1 mass %, and even more preferably 0.1 to 0.4%.

[0022] When the α-hydroxy acid contains malic acid, the concentration of malic acid in the topical agent and cosmetic for preventing and / or improving skin yellowing is preferably 0.0001 to 3 mass %, more preferably 0.01 to 1 mass %, and even more preferably 0.1 to 0.4 mass %.

[0023] When the α-hydroxy acid contains citric acid, the concentration of citric acid in the topical agent and cosmetic for preventing and / or improving skin yellowing is preferably 0.0001 to 3 mass %, more preferably 0.01 to 1 mass %, and even more preferably 0.1 to 0.4 mass %.

[0024] When the α-hydroxy acid contains tartaric acid, the concentration of tartaric acid in the topical agent and cosmetic for preventing and / or improving skin yellowing is preferably 0.0001 to 3 mass %, more preferably 0.01 to 1 mass %, and even more preferably 0.1 to 0.4 mass %.

[0025] When the α-hydroxy acid contains glycolic acid, the concentration of glycolic acid in the topical agent and cosmetic for preventing and / or improving skin yellowing is preferably 0.0001 to 3 mass %, more preferably 0.01 to 1 mass %, and even more preferably 0.1 to 0.4 mass %.

[0026] Examples of external preparations for preventing and / or improving skin yellowing include liniments, lotions, ointments, packs, solid soaps, liquid soaps, and the like.

[0027] Examples of cosmetics for preventing and / or improving skin yellowing include basic cosmetics such as lotion, cream, milky lotion, and serum; hair cosmetics such as shampoo, rinse, treatment, and hair growth and hair care products; makeup cosmetics such as liquid foundation and foundation milky lotion; and sunscreen cosmetics (including quasi-drugs). Quasi-drugs are products that have specific efficacy and effects and have a mild effect on the human body. Examples of quasi-drugs of the present invention include, but are not limited to, medicated cosmetics, medicated soap, medicated shampoo, medicated rinse, medicated bath additives, medicated baby powder, medicated baby lotion, medicated hair growth agent, and the like.

[0028] In addition, the skin yellowing prevention and / or improvement topical agent and cosmetic of the embodiment of the present invention is preferably a skin topical agent or a basic cosmetic, since it has a remarkable effect of preventing or suppressing skin yellowing.In addition, the skin yellowing prevention and / or improvement topical agent and cosmetic are not particularly limited, but can be aqueous, oil-in-water, water-in-oil, multi-layer emulsion, etc.In addition, the dosage form of the skin yellowing prevention and / or improvement topical agent and cosmetic can be any dosage form such as powder, liquid, milky lotion, paste, cream, gel, mousse, ointment, sheet, etc.

[0029] In addition to alpha hydroxy acid, the topical preparations and cosmetics for preventing and / or improving skin yellowing according to the embodiments of the present invention may contain, as appropriate, additives such as components used in topical preparations and cosmetics, namely, carriers such as water, alcohol, oils and fats, surfactants, excipients, emulsifiers, isotonicity agents, buffers, diluents, solubilizers, preservatives, stabilizers, antioxidants, gelling agents, powders, water-soluble polymers, UV protection agents, inclusion compounds, fragrances, salts, pH adjusters, animal or microbial extracts, plant extracts, blood circulation promoters, astringents, skin whitening agents, anti-inflammatory agents, active oxygen scavengers, cell activators, moisturizers, chelating agents, keratolytic agents, enzymes, hormones, vitamins, etc., within the scope of the invention.

[0030] The pH of the topical agent and cosmetic composition for preventing and / or improving skin yellowing according to the embodiment of the present invention is preferably pH 2-7, more preferably pH 3-6.

[0031] The method for producing the topical agent and cosmetic composition for preventing and / or improving skin yellowing of the present invention is not particularly limited, but examples include a method in which an α-hydroxy acid is added to water together with other ingredients as necessary, and then mixed.

[0032] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. EXAMPLES

[0033] Example 1 Establishment of an evaluation system for yellowing In the glycation pathway in vivo, glyoxal (GO), methylglyoxal (MG), glyceraldehyde (GA), etc. are generated as metabolic intermediates of glucose, which are further metabolized to generate advanced glycation end products (AGEs). This glycation reaction also occurs in the keratin of the skin. Taking advantage of the fact that glycated proteins turn yellow and that some AGEs have fluorescence, the present inventors established an evaluation system that causes yellowing due to glycation reactions using albumin, a typical protein that undergoes glycation reactions in vivo, and glyoxal (GO), an intermediate of glycation products. Below, we used this evaluation system to search for glycation inhibitors that prevent protein yellowing.

[0034] Specifically, bovine serum albumin (BSA) was dissolved in phosphate buffer (PBS(-)) to a concentration of 100 mg / ml, and glyoxal (GO) was added to the BSA solution to a concentration of 25 mM and mixed. Next, aminoguanidine (AG), a representative glycation inhibitor, was added to the mixture to a concentration of 1.56 mM to 100 mM, and the mixture was allowed to react at 37°C for 24 hours.

[0035] For each sample obtained, the absorbance (415 nm), which indicates the degree of yellowing, and the fluorescence intensity (excitation light 365 nm, emission 450 nm) of many glycation products were measured before (0 hr) and after (24 hr) the reaction, as indicators of the production of glycation products.

[0036] (result) As shown in Figure 1A, the fluorescence intensity of aminoguanidine decreased over the entire concentration range of 1.56 mM to 100 mM, but as shown in Figure 1B (graph enclosed in a square frame) and Figure 1C, the absorbance increased over the concentration range of 1.56 mM to 12.5 mM. Similar results were obtained when methylglyoxal (MG) or glyceraldehyde (GA) was used instead of glyoxal (GO) (data not shown). In other words, this result indicates that inhibition of glycation does not necessarily prevent yellowing, and a glycation inhibitor that inhibits both glycation and yellowing is desired.

[0037] Example 2 Evaluation using methylglyoxal Using methylglyoxal (MG) instead of glyoxal (GO), the absorbance and fluorescence intensity of each sample were measured in the same manner as in Example 1. As a result, similar results were obtained (data not shown).

[0038] Example 3 Evaluation using glyceraldehyde Using glyceraldehyde (GA) instead of glyoxal (GO), the absorbance and fluorescence intensity of each sample were measured in the same manner as in Example 1. As a result, similar results were obtained (data not shown).

[0039] Example 4 Evaluation of Lactic Acid In this example, lactic acid, which is one of alpha hydroxy acids (AHA), was evaluated using the yellowing evaluation system of Example 1. However, intermediates of glycation products were prepared by adding glyoxal (GO), methylglyoxal (MG), and glyceraldehyde (GA) to a BSA solution at 25 mM each and mixing them. The lactic acid concentrations were 0%, 0.1%, 0.2%, and 0.4% in terms of mass to volume percentage (w / v%) (Figure 2A).

[0040] (result) As shown in Figures 2B and C, lactate reduced the amount of absorbent and fluorescent glycation products in a concentration-dependent manner in the concentration range of 1.56 mM to 100 mM. The absorbance and fluorescence intensities were calculated by subtracting the values ​​before and after the reaction from the values ​​after the reaction.

[0041] Surprisingly, we found that lactic acid has an excellent effect of suppressing both the absorbance and fluorescence intensity of glycation products, and is an excellent substance for preventing the yellowing induced by protein glycation.

[0042] Example 5 Evaluation of various alpha hydroxy acids In this example, various α-hydroxy acids (lactic acid, malic acid, citric acid, tartaric acid, glycolic acid) were evaluated using the yellowing evaluation system of Example 1. The intermediate glycation product was prepared by adding glyoxal (GO) to a BSA solution to a concentration of 25 mM and mixing. The α-hydroxy acid concentration was 0.1% in terms of mass to volume percentage (w / v%).

[0043] (result) As shown in Figures 3A and B, among the five types examined, lactic acid tended to reduce both the amounts of absorbent and fluorescent glycation products, but the other α-hydroxy acids were generally effective in suppressing both absorbance and fluorescence intensity.

[0044] Example 6 Evaluation of various alpha hydroxy acids in various concentration ranges In this example, various α-hydroxy acids (α-hydroxy acid mixture, lactic acid, malic acid, citric acid, tartaric acid, glycolic acid) were evaluated using the yellowing evaluation system of Example 1. However, the intermediate glycation product was prepared by adding glyoxal (GO) to 100 mg / ml BSA phosphate buffer to a concentration of 25 mM and mixing. Next, various α-hydroxy acids were added to the mixture.

[0045] The alpha hydroxy acid mixture has the following composition in terms of mass to volume percentage (w / v%): lactic acid 36.23%, malic acid 0.29%, citric acid 13.34%, and other moisturizing ingredients, prepared as an aqueous solution to make 100%.

[0046] (result) As shown in Table 1, when glyoxal (GO) was used as an intermediate, all of the α-hydroxy acids suppressed both the absorbance and fluorescence intensity in the low concentration range.

[0047] As shown in Table 2, even when methylglyoxal (MO) was used as an intermediate, all of the α-hydroxy acids suppressed both the absorbance and fluorescence intensity in the low concentration range.

[0048] As shown in Table 3, even when glyceraldehyde (GA) was used as an intermediate, all of the α-hydroxy acids suppressed both the absorbance and fluorescence intensity in the low concentration range.

[0049] In addition, since high concentrations of alpha hydroxy acids cause gelation of BSA, making accurate measurement difficult, Table 1-3 measures the absorbance or fluorescence intensity of samples with up to 0.2%, 0.4%, or 0.8% alpha hydroxy acids, but this does not mean that high concentrations of alpha hydroxy acids exceeding the upper limit of concentrations in Table 1-3 cannot suppress the absorbance and fluorescence intensity. No gelation occurred in the alpha hydroxy acid mixture at the measured concentrations, and the sample condition was homogeneous and good.

[0050] [Table 1]

[0051] [Table 2]

[0052] [Table 3]

[0053] Example 7 Evaluation of antioxidants Since part of the glycation reaction process is an oxidation reaction, antioxidants are expected to have a glycation inhibitory effect. Since α-hydroxy acids also have antioxidant effects, in this example, the glycation inhibitory effects of representative antioxidants L-ascorbic acid (vitamin C) and Trolox (a water-soluble analog of vitamin E, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) were evaluated using the yellowing evaluation system of Example 1 in order to compare the glycation inhibitory effects of antioxidants.

[0054] [ka]

[0055] (result) As shown in Figure 4, no suppression of absorbance or fluorescence intensity was observed with increasing concentration of L-ascorbic acid, and the absorbance actually increased at concentrations of 0.05 w / v% or more. As shown in Figure 5, no suppression of absorbance or fluorescence intensity was observed with Trolox up to 0.1 w / v%, and a tendency for the absorbance and fluorescence intensity to be suppressed at 0.5%, but at 1 w / v%, the reagent precipitated, making accurate measurement difficult. All of the representative antioxidants had weaker effects as glycation inhibitors, reducing both fluorescence intensity and absorbance, than α-hydroxy acids.

[0056] Example 8: Test for preventing and / or improving skin yellowing in humans The components in Table 4 were mixed and dissolved uniformly to prepare a lotion, which was recorded as Example 8. The same α-hydroxy acid mixture as in Example 6 was used.

[0057] Two adults applied the prepared lotion to the inside of the left forearm and 1 mL of Comparative Example 1 to the inside of the right forearm twice a day for 14 days. th day), after the test (14 th The color difference b* value was measured on each day, and the change in the b* value after the test compared to the b* value before the test was taken as the Δb value (average value) to evaluate the skin color.

[0058] As shown in Table 5, the lotion of Example 8 containing alpha hydroxy acid had the effect of preventing and / or improving skin yellowing compared to the lotion of Comparative Example 1 containing no alpha hydroxy acid, demonstrating that the effect of alpha hydroxy acid in preventing and / or improving yellowing is also effective on human skin.

[0059] [Table 4]

[0060] [Table 5]

[0061] Example 9 The following are examples of cosmetic products according to the present invention, Formulation Examples 1 to 6. The same α-hydroxy acid mixture as in Example 6 was used. Formulation example 1: Lotion Ingredients Amount (mass%) Dipropylene glycol 8.0 Glycerin 8.0 Sorbitol 3.0 Polyquaternium-51 0.004 PEG1500 1.0 Tremella polysaccharide 0.005 Inositol 1.0 Chelating agent (EDTA-2Na) 0.01 Preservative (appropriate amount) Alpha Hydroxy Acid Mixture 2.0 Purified water Remainder (total amount is 100) (Production method) Each component is weighed out and mixed uniformly.

[0062] Formulation example 2 Emulsion Ingredients Amount (mass%) Part A Polyglyceryl-10 Myristate 2.1 Hydrogenated lecithin 0.6 Stearic acid 0.5 Behenyl alcohol 1.6 Cetyl palmitate 0.6 Olefin Oligomer 6.0 Cetyl ethylhexanoate 6.0 Triethylhexanoin 6.0 Part B Purified water Remainder (total amount is 100) Preservative (appropriate amount) C part Carbomer 0.1 Purified water 9.9 D part Potassium hydroxide 0.05 Purified water 4.95 Part E Alpha Hydroxy Acid Mixture 1.0 (Production method) Weigh out A through E. Heat A and B to 80°C, and add B while stirring A with a homomixer. Cool with stirring, and add C through E in order and mix.

[0063] Formulation example 3 Cream Ingredients Amount (mass%) Part A Hydrogenated polyisobutene 5.3 Ethylhexyl palmitate 3.0 Olive oil 5.0 Beeswax 3.0 Cetanol 3.0 Stearyl Alcohol 2.0 Glyceryl Stearate 2.0 PEG-75 Stearate 1.0 Polysorbate 60 1.0 Preservative (appropriate amount) Part B Purified water Remainder (total amount is 100) Glycerin 4.0 Preservative (appropriate amount) C part Alpha Hydroxy Acid Mixture 1.0 (Production method) Weigh out A, B, and C. Heat A and B to 80℃, and add B while stirring A with a homomixer. Cool while stirring, add C, and mix uniformly.

[0064] Formulation example 4 Gel Ingredients Amount (mass%) Part A Carbomer 0.45 (Acrylates / alkyl acrylate (C10-30)) crosspolymer 0.3 Purified water 60.0 Part B Potassium hydroxide 0.07 Purified water 1.0 C part Glycerin 7.0 1,3-Butylene glycol 8.0 Alpha hydroxy acid mixture 0.1 Preservative (appropriate amount) Purified water Remainder (total amount is 100) D part Dimethicone / Dimethiconol Mixture 2.0 (Production method) Weigh out A to D. Disperse A, then add B to neutralize. Add C and D and mix evenly.

[0065] Formulation example 5 Pump foam type face wash Ingredients Amount (mass%) Sorbitol 25.0 Diglycerin 4.0 Lauryl Hydroxysultaine 0.5 Sodium Cocoyl Glutamate 0.5 Decyl glucoside 3.0 1,3-Butylene glycol 5.0 Alpha Hydroxy Acid Mixture 1.0 Preservative (appropriate amount) Purified water Remainder (total amount is 100) (Production method) Each component is weighed out and mixed uniformly.

[0066] Mixture Example 6 Gommage Ingredients Amount (mass%) Part A Squalane 5.0 Stearic acid 1.0 Glyceryl stearate 1.0 PEG-60 hydrogenated castor oil 1.0 Dimethicone 0.5 Part B Glycerin 2.5 1,3-Butylene glycol 2.5 Preservative (appropriate amount) C part Carbomer 0.2 Purified water 10.0 D part Potassium hydroxide (appropriate amount) Purified water Remainder (total amount is 100) Part E Polyisoprene 5.0 F part Alpha hydroxy acid mixture 0.5 (Production method) Weigh out A to E. Heat A and B to 80°C, and add B while stirring A with a homomixer. Disperse C, then add it to the AB mixture. Neutralize with D, then add E and F and mix.

Claims

1. An external preparation for preventing and / or improving skin yellowing, which contains alpha hydroxy acids including lactic acid, malic acid, and citric acid (excluding the improving agent (I) and external skin preparation (II) below). (I) A skin color improving agent containing an advanced glycation end product decomposer which is the following (bi), (b-ii), or (b-iii): (bi) at least one member selected from the group consisting of unsaturated fatty acids, and pharma- ceutically acceptable salts thereof, pharma-ceutically acceptable glycerides thereof, pharma-ceutically acceptable esters thereof, and pharma-ceutically acceptable amides thereof; (b-ii) A vegetable oil containing at least one selected from the group consisting of unsaturated fatty acids and pharma- ceutically acceptable derivatives thereof. (b-iii) Plant extracts with AGEs decomposition effect (II) A skin external preparation for reducing yellowing of the skin, comprising hesperetin and / or glycosyl hesperetin as an active ingredient.

2. 2. The external preparation for preventing and / or improving skin yellowing according to claim 1, wherein the concentration of the alpha hydroxy acid in the external preparation for preventing and / or improving skin yellowing is 0.001 to 5% by mass.

3. A cosmetic preparation for preventing and / or improving skin yellowing, which contains alpha hydroxy acids including lactic acid, malic acid, and citric acid (excluding the improving agent (I) and topical skin preparation (II) below). (I) A skin color improving agent containing an advanced glycation end product decomposer which is the following (bi), (b-ii), or (b-iii): (bi) at least one member selected from the group consisting of unsaturated fatty acids, and pharma- ceutically acceptable salts thereof, pharma-ceutically acceptable glycerides thereof, pharma-ceutically acceptable esters thereof, and pharma-ceutically acceptable amides thereof; (b-ii) A vegetable oil containing at least one selected from the group consisting of unsaturated fatty acids and pharma- ceutically acceptable derivatives thereof. (b-iii) Plant extracts with AGEs decomposition effect (II) A skin external preparation for reducing yellowing of the skin, comprising hesperetin and / or glycosyl hesperetin as an active ingredient.

4. 4. The cosmetic composition for preventing and / or improving skin yellowing according to claim 3, wherein the concentration of the alpha hydroxy acid in the cosmetic composition for improving skin yellowing is 0.001 to 5% by mass.

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