Agents that inhibit the secretion and / or expression of SASP factors in keratinocytes, and agents that promote metabolic improvement.

Abstract

To provide a novel agent for inhibiting the secretion and / or expression of SASP factors by keratinocytes, as well as an agent for improving keratinocyte metabolism. [Solution] The present invention provides an inhibitor of the secretion and / or expression of SASP factor by keratinocytes, comprising one or more selected from the group consisting of GK2, TA, and 4MSK and their analogs as active ingredients, and a keratinocyte metabolism improvement promoter comprising TA and / or its analog, K2 and / or its analog, and 4MSK and / or its analog.

Description

[Technical Field]

[0001] The present invention provides a method for treating keratinocyte-associated secretory phenomena ( S enescence- A ssociated S ecretory P The present invention relates to an agent for inhibiting the secretion and / or expression of SASP (serotype phenotype: SASP) factors. [Background technology]

[0002] In order to improve pigmentation and dullness, it is important to suppress excessive melanin production by melanocytes and excessive melanin accumulation in epidermal keratinocytes. Therefore, in order to suppress melanin production in melanocytes, agents such as compounds and plant extracts that inhibit the expression, activity, or decomposition of tyrosinase (hereinafter referred to as whitening agents) have been developed and used, and in order to suppress melanin production in epidermal cells, whitening agents that promote epidermal turnover (cell proliferation and cell differentiation) and excrete melanin accumulated in epidermal keratinocytes have been developed and used. Melanin naturally functions to protect epidermal cells from DNA damage when exposed to UV rays during the day. For example, epidermal keratinocytes take up melanin and form a structure called a melanin cap around the cell nucleus, preventing DNA damage in the cell nucleus. Therefore, artificially promoting the excretion of melanin or the suppression of melanin production excessively impairs the original function of melanin, which is thought to have a negative impact on skin health.

[0003] As mentioned above, conventional whitening agents have three main functions: inhibiting melanin production, inhibiting excessive melanin uptake in epidermal keratinocytes, and promoting epidermal turnover. Excessive activation of these three effects can lead to the development of vitiligo and the impairment of melanin's inherent skin defense function. In particular, abnormalities in epidermal cell differentiation and chronic inflammation are thought to be the main causes of dark spots. Therefore, by fundamentally improving these abnormalities, it is necessary to address the dark spot-specific excessive melanin accumulation in a way that conventional whitening agents cannot.

[0004] On the other hand, age spots are caused by a complex combination of factors, including chronic inflammation, excessive melanin accumulation in keratinocytes, and abnormal cell differentiation. While the effectiveness of various whitening agents has been confirmed for these internal skin phenomena, there has been no detailed investigation into the additive or synergistic whitening effects of combining conventional whitening agents with agents that have other efficacy and effects, such as skin roughness, moisturizing, or anti-inflammatory effects. In other words, no studies have explored the combination of conventional whitening agents with agents that have anti-skin roughness or anti-inflammatory properties, thereby improving metabolism and inhibiting cell aging while boosting the whitening effect and improving age spots. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Birch et al., Genes Dev. 2020 Dec 1;34(23-24):1565-1576 (Senescence and the SASP: many therapeutic avenues) Summary of the Invention [Problem to be solved by the invention]

[0006] To provide a novel agent for inhibiting the secretion and / or expression of SASP factors by keratinocytes, as well as an agent for improving keratinocyte metabolism. [Means for solving the problem]

[0007] As a result of extensive research into skin whitening agents, the present inventors have surprisingly found that GK2, TA, and 4MSK inhibit the secretion and / or expression of SASP factors by keratinocytes. Therefore, they have found that by combining 4MSK and TA, which are conventionally used as main skin whitening agents, with GK2, which is known for its whitening effects as an anti-rough skin and anti-inflammatory agent, it is possible to boost the effects of 4MSK and TA while improving metabolism and inhibiting cell aging. Furthermore, they have found that the combination of GK2, TA, and 4MSK has a metabolic improvement effect.

[0008] It has been reported that aging causes cells to express and secrete various factors, such as inflammatory cytokines, chemokines, growth factors, and extracellular matrix degrading enzymes, resulting in a phenomenon known as SASP. SASP is known to induce chronic inflammation and promote the onset of various age-related diseases, including cancer (Non-Patent Document 1). Therefore, suppressing the secretion and expression of SASP factors is important for maintaining homeostasis and preventing disease.

[0009] The present application provides the following inventions. (1) An agent for inhibiting the secretion and / or expression of SASP factors by keratinocytes, which contains as an active ingredient one or more selected from the group consisting of GK2, TA, 4MSK and analogs thereof. (2) An inhibitor of the secretion and / or expression of the SASP factor in (1), wherein the SASP factor is GROα(CXCL1). (3) An agent for inhibiting the secretion and / or expression of SASP factors according to (1) or (2), in which the secretion and / or expression of SASP factors is promoted by excessive accumulation of melanin in keratinocytes. (4) An inhibitor of the secretion and / or expression of any of the SASP factors (1) to (3) that is effective in improving keratinocyte aging caused by excessive melanin accumulation. (5) A secretion and / or expression inhibitor of any of the SASP factors (1) to (4), comprising TA and / or an analogue thereof and GK2 and / or an analogue thereof. (6) An inhibitor of the secretion and / or expression of any of the SASP factors (1) to (5), comprising TA and / or an analog thereof and 4MSK and / or an analog thereof. (7) A secretion and / or expression inhibitor of any of the SASP factors (1) to (6), comprising TA and / or its analogue, GK2 and / or its analogue, and 4MSK and / or its analogue. (8) A keratinocyte metabolism improvement promoter comprising TA and / or an analog thereof, GK2 and / or an analog thereof, and 4MSK and / or an analog thereof. (9) A method for screening keratinocytes for suppressing the secretion and expression of SASP factors, wherein candidate drugs are added to keratinocytes with excessive melanin accumulation and cultured, and the secreted or expressed SASP factors are used as indicators. (10) The screening method according to (9), wherein the SASP factor is GROα (CXCL1). (11) The screening method of (9) or (10), wherein the candidate drug screened as an inhibitor of the secretion and / or expression of SASP factor by keratinocytes is a keratinocyte metabolism improvement promoter. [Effects of the Invention]

[0010] The present invention provides a novel agent for inhibiting the secretion and expression of SASP factors and a novel agent for promoting the improvement of keratinocyte metabolism. [Brief explanation of the drawings]

[0011] [Figure 1] 1 shows the in vitro inhibitory effect of 4MSK, TA and / or GK2 on the secretion of SASP factor (GROα). [Figure 2] The triple combination of 4MSK / TA / GK2 exhibits cell metabolic activation effects in vivo. DETAILED DESCRIPTION OF THE INVENTION

[0012] In a first aspect, the present application provides an agent for inhibiting the secretion and / or expression of SASP factors by keratinocytes, which comprises, as an active ingredient, one or more selected from the group consisting of GK2, TA, and 4MSK, and analogs thereof.

[0013] Dipotassium glycyrrhizinate (GK2) is a plant-derived triterpene glycoside derived from glycyrrhizic acid extracted from the rhizome or root of licorice, which has been made more soluble in water. It is known to have anti-inflammatory, anti-allergic, antitumor, antiviral, antifibrinolytic, and irritation-relieving properties, and is incorporated into various cosmetics. There is no known evidence that dipotassium glycyrrhizinate has the effect of inhibiting the secretion and expression of SASP factors by keratinocytes or promoting the improvement of keratinocyte metabolism. Analogs of dipotassium glycyrrhizinate referred to in this invention include its precursor, glycyrrhizic acid, as well as monopotassium glycyrrhizinate, disodium glycyrrhizinate, ammonium glycyrrhizinate, and glycyrrhizinate esters.

[0014] Tranexamic acid (TA) has antiplasmin activity and is incorporated into various cosmetics as an active ingredient for improving rough skin and whitening, etc. However, there is no evidence that tranexamic acid has the effect of suppressing the secretion and expression of SASP factors by keratinocytes or promoting the improvement of keratinocyte metabolism. Analogues of tranexamic acid as used in this invention include its derivatives or salts thereof. Examples of tranexamic acid derivatives include tranexamic acid (trans-4-aminomethylcyclohexane-1-carboxylic acid), tranexamic acid esters (e.g., vitamin esters such as vitamin A ester, vitamin E ester, vitamin C ester, and vitamin D ester, phenyl esters, hydroquinone esters, gentisic acid esters, etc.), tranexamic acid amide (methylamide or salt thereof, etc.), tranexamic acid dimers, etc. There are no particular restrictions on the salt of tranexamic acid, and can be appropriately selected depending on the purpose. Examples include alkali metal salts such as sodium salt and potassium salt; alkaline earth metal salts such as calcium salt and magnesium salt; zinc salt; iron salt; ammonium salt; basic amino acid salts such as arginine, lysine, histidine, and ornithine; and amine salts such as monoethanolamine, diethanolamine, and triethanolamine.

[0015] Potassium 4-methoxysalicylate (4MSK) is known to have an effect in preventing age spots and freckles, and to promote skin cell turnover, thereby expelling melanin along with old keratinocytes. There is no evidence that potassium 4-methoxysalicylate has an effect of suppressing the secretion and expression of SASP factors by keratinocytes or promoting the improvement of keratinocyte metabolism. Analogues of potassium 4-methoxysalicylate as used in this invention include amine derivatives, acetyl derivatives, fluoro derivatives, or their ester derivatives.

[0016] As mentioned at the beginning, cellular senescence induces a phenomenon known as SASP, which is known to induce chronic inflammation and promote the onset of various age-related diseases, including cancer. Therefore, suppressing the secretion and expression of SASP factors is important for maintaining homeostasis and preventing diseases.

[0017] SASP factors include, but are not limited to, inflammatory cytokines, chemokines, growth factors, and extracellular matrix degrading enzymes, such as GRO-α, GRO-β, GRO-γ, GM-CSF, IGFBP-7, IL-1α, IL-6, IL-7, IL-8, MCP-1, MCP-2, MIP-1α, MMP-1, MMP-10, MMP-3, amphiregulin, ENA-78, iotaxin-3, GCP-2, GITR, HGF, ICAM-1, IGFBP-2, IGFBP-4, and IGFBP- 5, IGFBP-6, IL-13, IL-1β, MCP-4, MIF, MIP-3α, MMP-12, MMP-13, MMP-14, NAP2, oncostatin M, osteoprotegerin, PIGF, RANTES, sgp130, TIMP-2, TRAIL-R3, Acrp30, angiogenin, Axl, bFGF, BLC, BTC, CTACK, EGF-R, Fas, FGF-7, G-CSF, GDNF, HCC-4, I-309, IFN-γ, IGFBP-1, IGFBP-3, IL-1 Examples of such proteins include R1, IL-11, IL-15, IL-2R-α, IL-6R, I-TAC, leptin, LIF, MMP-2, MSP-α, PAI-1, PAI-2, PDGF-BB, SCF, SDF-1, sTNF RI, sTNF RII, thrombopoietin, TIMP-1, tPA, uPA, uPAR, VEGF, MCP-3, IGF-1, TGF-β, MIP-1-delta, IL-4, FGF-7, PDGF-BB, IL-16, BMP-4, MDC, MCP-4, IL-10, TIMP-1, Fit-3 ligand, ICAM-1, Axl, CNTF, INF-γ, EGF, and BMP-6. GROα is particularly preferred.

[0018] The present inventors have further discovered the new finding that putting keratinocytes into a state of excessive melanin accumulation results in high secretion and expression of SASP factors. Therefore, in a further aspect, the present application provides a method for screening for agents that inhibit the secretion and expression of SASP factors by keratinocytes, using excessive melanin accumulation keratinocytes. Specifically, the present application provides a method for screening for agents that inhibit the secretion and expression of SASP factors by keratinocytes, in which a candidate drug is added to excessive melanin accumulation keratinocytes and the cells are cultured, and the secreted or expressed SASP factors are used as indicators.

[0019] More specifically, the screening method of the present invention comprises the following steps: (1) culturing keratinocytes in a medium containing melanin and allowing the keratinocytes to phagocytose melanin; (2) a step of washing and removing unphagocytosed melanin; (3) culturing keratinocytes that have accumulated excessive melanin due to melanin phagocytosis in a medium containing a candidate drug; and (4) Measuring the secretion or expression of SASP factors in keratinocytes with excessive melanin accumulation.

[0020] If the secretion or expression level of an SASP factor is suppressed, the candidate drug can be considered to have an inhibitory effect on the secretion or expression of an SASP factor. The secretion or expression level of an SASP factor, for example, in the case of GROα / CXCL1, can be measured by immunoassay of the secreted protein using a commercially available kit as described in the Examples, or by PCR such as RT-PCR, and is not particularly limited.

[0021] Inhibition of secretion or expression of SASP factors can mean, for example, that the secretion or expression is reduced with a statistically significant difference (e.g., Wilcoxon rank sum test, t-test, etc.) with a significance level of 5%, for example, compared to keratinocytes with excessive melanin accumulation cultured without the drug, or that the secretion or expression is reduced by, for example, 5% or more, 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 100%.

[0022] In a further aspect, the present invention provides a metabolic improving agent which is a combination of three drugs: GK2, TA and 4MSK. By measuring and analyzing the fluorescence lifetime of electron carriers in the epidermal granular layer in pigmented and non-pigmented areas of the skin, it has been found that the level of oxidative phosphorylation metabolism based on the fluorescence lifetime of the electron carrier differs between pigmented and non-pigmented areas, and that the metabolism of oxidative phosphorylation is lower in pigmented areas compared to healthy skin (non-pigmented areas) (Patent Application No. 2024-003897). Therefore, the level of oxidative phosphorylation in the granular layer can be used to non-invasively evaluate the condition of pigmented skin, and can serve as an evaluation index for investigating the degree of pigmented skin and the effectiveness of its improvement.

[0023] Specifically, this skin condition evaluation method includes the steps of irradiating the skin of a subject with excitation light for an electron carrier and measuring the fluorescence lifetime of the electron carrier in the granular layer using a multiphoton scanning laser biomicroscope (measurement step), analyzing the level of oxidative phosphorylation of the electron carrier in the granular layer based on the fluorescence lifetime of the electron carrier (analysis step), and evaluating the skin condition according to the level of oxidative phosphorylation in the granular layer (evaluation step). The electron carrier here is at least one of nicotinamide adenine dinucleotide (NADH), nicotinamide adenine dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), and reduced flavin adenine dinucleotide (FADH2). They also found that skin condition can be evaluated as a metabolic abnormality, such as a skin metabolic abnormality caused by oxidative phosphorylation metabolism (decrease or increase), with respect to oxidative phosphorylation metabolism. As a result, they found that when the level of oxidative phosphorylation in the granular layer is high, the skin condition can be evaluated as good, and when a decrease in oxidative phosphorylation metabolism is observed, the level of oxidative phosphorylation in the granular layer is low, and the skin condition can be evaluated as poor.

[0024] By carrying out the above-mentioned method for evaluating skin condition, the present inventors have found that a combination of the three drugs GK2, TA, and 4MSK can improve the decrease in metabolic activity associated with a decrease in cellular oxidative phosphorylation.

[0025] The "suppressant of SASP factor secretion and / or expression by keratinocytes" and the "keratinocyte metabolism improvement promoter" (hereinafter sometimes referred to as "the agent of the present invention") of the present invention may also be a composition in which an active ingredient such as GK2, TA, 4MSK, or analogs thereof is combined with one or more other ingredients, such as excipients, carriers and / or diluents. The composition and form of the composition are arbitrary and should be appropriately selected according to the active ingredient, application, and other conditions. The composition can be manufactured using conventional methods in a formulation that appropriately combines excipients, carriers and / or diluents and other ingredients according to its dosage form.

[0026] The agent of the present invention may be incorporated into cosmetics and used in humans and animals, or it may be applied to humans and animals as a pharmaceutical preparation.

[0027] When the agent of the present invention is used as a topical skin preparation such as a cosmetic, pharmaceutical, or quasi-drug, the amount of GK2 or its analogues can be appropriately determined according to their type, purpose, form, and method of use. For example, it may be 0.001 to 10% by weight of the total amount of the topical skin preparation, preferably 0.005 to 5% by weight, more preferably 0.01 to 2% by weight, and even more preferably 0.05 to 1% by weight. Similarly, the amount of TA or its analogues incorporated can be appropriately determined according to their type, purpose, form, and method of use. For example, it may be 0.01 to 20% by weight of the total amount of the topical skin preparation, preferably 0.1 to 15% by weight, more preferably 0.5 to 10% by weight, and even more preferably 1 to 5% by weight. Similarly, the amount of 4MSK or its analogues can be appropriately determined depending on their type, purpose, form, and method of use. For example, it may be 0.01 to 20% by weight of the total amount of the topical skin preparation, preferably 0.1 to 15% by weight, more preferably 0.5 to 10% by weight, and even more preferably 1 to 5% by weight.

[0028] In addition to the above components, if necessary, and within the limits that do not impair the effects of the present invention, components commonly used in topical skin preparations such as cosmetics, pharmaceuticals, and quasi-drugs, such as antioxidants, oils, UV protection agents, surfactants, thickeners, alcohols, powder components, colorants, aqueous components, water, and various skin nutrients may be added as needed.

[0029] Furthermore, metal ion sequestering agents such as disodium edetate, trisodium edetate, sodium citrate, sodium polyphosphate, sodium metaphosphate, and gluconic acid; preservatives such as methylparaben, ethylparaben, and butylparaben; drugs such as caffeine, tannins, verapamil, tranexamic acid and its derivatives, glabridin, hot water extract of quince fruit, various herbal medicines, tocopherol acetate, glycyrrhizic acid and its derivatives or salts; whitening agents such as vitamin C, magnesium ascorbate phosphate, ascorbate glucoside, arbutin, and kojic acid; and sugars such as glucose, fructose, mannose, sucrose, and trehalose can also be added as appropriate.

[0030] When the agent of the present invention is used as a topical skin preparation, it can be applied to the skin as a cosmetic, quasi-drug, etc., and is particularly suitable as a cosmetic. The dosage form is not limited as long as it can be applied to the skin, and any dosage form can be used, such as solution systems, solubilization systems, emulsions, powder dispersion systems, water-oil two-layer systems, water-oil-powder three-layer systems, ointments, lotions, gels, aerosols, etc.

[0031] When the agent of the present invention is used in cosmetics, it may be used in the form of lotion, emulsion, foundation, lipstick, lip balm, cleansing cream, massage cream, mask, hand cream, hand powder, body shampoo, body lotion, body cream, bath cosmetics, etc.

[0032] When the agent of the present invention is used as a formulation of a drug or quasi-drug, it can be used in various forms such as a lotion, suspension, emulsion, solution, ointment, patch, etc. These formulations may contain appropriate excipients such as commonly used binders, disintegrants, thickeners, dispersants, resorption promoters, flavoring agents, buffers, surfactants, solubilizers, preservatives, emulsifiers, tonicity agents, stabilizers, and pH adjusters.

[0033] However, the forms that the agent of the present invention can take are not limited to the dosage forms and shapes described above.

[0034] All documents mentioned herein are incorporated by reference in their entirety.

[0035] The following examples of the present invention are for illustrative purposes only and do not limit the technical scope of the present invention. The technical scope of the present invention is limited only by the claims. The present invention may be modified, for example, by adding, deleting, or substituting components of the present invention, provided that the modifications do not depart from the spirit of the present invention. [Example]

[0036] Experiment 1: Screening protocol for inhibitory effects on GROα / CXCL1 secretion Experimental Method Synthetic melanin (M0418, Sigma-Aldrich) was suspended in 1.5 ml of Eppendorf tubes in 1x PBS to a concentration of 1% (w / v) and sonicated in a sonication bath for 2 hours at room temperature. This sonicated synthetic melanin was diluted in Epilife (MEPI500CA, Thermo Fisher Scientific) keratinocyte medium to a final concentration of 0.004%. Keratinocytes were seeded in 50,000 cell-well 24-well plates (IWAKI), replaced with the 0.004% melanin dilution medium, and cultured at 37°C and 5% CO2 for 12 hours. Subsequently, the plates were washed twice with 1 ml / well of 1x PBS to remove extracellular or intracellular melanin that was not phagocytosed by the keratinocytes. After washing, the plates were replaced with regular Epilife medium without melanin. As a control, keratinocyte cultures treated under the same conditions without the addition of synthetic melanin were prepared.

[0037] To measure the protein concentration of GROα / CXCL1, a SASP factor secreted into the culture medium in a melanin accumulation-dependent manner, in the culture supernatant, the following process was followed. Each screening agent was suspended in Epilife to reach a predetermined final concentration, added to melanin-accumulating keratinocytes, and cultured for 4 days (without changing the medium). After 4 days of culture, the culture supernatant was collected, and GROα / CXCL1 secreted into the culture supernatant was detected using a microplate reader (POWERSCANT, BioTek) according to the Human CXCL1 / GROalpha Quantikine kit (DGR00B, RD systems) protocol. To correct for the GROα / CXCL1 protein concentration relative to the number of viable cells, keratinocyte samples from 24 wells used in each measurement were nuclear-stained with Hoechist 33258, and the relative cell number was measured using a microplate reader. Ultimately, the effect of the drug was calculated as the GROα / CXCL protein concentration secreted from each melanin-accumulating keratinocyte sample, corrected for the number of cells. The drugs screened using the above method were 4MSK (1%), TA (2%), GK2 (0.5%), or combinations thereof. The values ​​in parentheses are the specified final concentrations for each drug.

[0038] GROα / CXCL1 secretion inhibitory effect of each drug Figure 1 (A and B) shows the inhibitory effect of each drug on the secretion of the SASP factor GROα / CXCL1. It can be seen that GK2 alone, TA + GK2, and 4MSK + TA + GK2 have an inhibitory effect on GROα / CXCL1 secretion. In particular, the combination of 4MSK + TA + GK2 showed a particularly remarkable inhibitory effect on GROα / CXCL1 secretion.

[0039] Experiment 2: The combination of GK2, TA, and 4MSK improves cellular metabolism. Experimental Method Multiphoton laser tomography and fluorescence lifetime microscopy ( F luorescence L ifetime I Maging M Non-invasive measurement procedure for cellular metabolism in senile lentigines using icroscopy (FLIM) analysis. As described above, by measuring and analyzing the fluorescence lifetime of the electron carrier in the granular layer of facial senile lentigo (hereinafter referred to as age spots) and non-senile lentigo (hereinafter referred to as non-age spots) areas, it has been found that the level of oxidative phosphorylation metabolism based on the fluorescence lifetime of the electron carrier differs between age spots and non-age spots, and that the metabolism of oxidative phosphorylation is lower in age spots compared to healthy skin (non-age spots). Therefore, the level of oxidative phosphorylation in the granular layer can be used to non-invasively evaluate the skin condition of age spots, and this can serve as a new evaluation index for investigating the effect of improving age spots.

[0040] This evaluation was conducted with the approval of the Shiseido Ethics Committee (Approval numbers: c10290, c10382, and B10430). To evaluate the clinical efficacy of the 4MSK+TA+GK2 tripartite combination, 19 female participants aged 40-59 years with blemishes on both sides of their cheeks were carefully selected. Participants applied either a placebo serum or a serum containing the 4MSK / TA / GK2 tripartite combination (1% MSK, 2% TA, 0.05% GK2) to each side of their face separately for 6 weeks. Measurements were taken in one blemished area and one non-blemished area, and the metabolic activity of mitochondrial OXPHOS (oxidative phosphorylation) was compared from the fluorescence lifetime of NADPH in those areas. In vivo skin measurements were performed by clinical multiphoton tomography using MPTflex (JenLab) at an excitation wavelength of 760 nm and a maximum power of 10 mW. Fluorescence lifetime analysis was performed on the cytoplasm of cells in the granular layer of the epidermis using SPCImage software (Becker & Hickl). Fluorescence decay curves were fitted using either a bi-exponential or tri-exponential decay model depending on the experimental data. Three to five regions of interest (ROIs) within the cytoplasm were analyzed for FLIM images. To distinguish the NAD(P)H lifetime component from other fluorescent substances (melanin) that are noise, the phasor display was analyzed. The amplitude of bound NADPH lifetime relative to free NADPH lifetime (A bound NADPH / A free NADPH ) values ​​were calculated to determine the metabolic shift.

[0041] To evaluate whether 4MSK / TA / GK2 can improve the microenvironment of pigmented spots, a study was conducted in which a placebo serum was applied to one side of the face and a 4MSK / TA / GK2-formulated serum was applied to the other side for 6 weeks, and metabolic activity in pigmented spots and adjacent non-pigmented areas was measured by FLIM (Figure 2A). In week 0, A bound NADPH / A free NADPH was significantly reduced in the pigmented spots compared with the adjacent non-pigmented areas (Fig. 2B). Interestingly, the use of the 4MSK / TA / GK2 formulation rather than placebo significantly reduced A bound NADPH / A free NADPH The results suggest that oxidative phosphorylation activity is enhanced in both pigmented and non-pigmented areas (Fig. 2C). The above results provide new insight that the 4MSK / TA / GK2 preparation efficiently enhances oxidative phosphorylation metabolism in pigmented spots. Based on the above findings from in vivo efficacy studies, we suggest that 4MSK / TA / GK2 improves both the metabolic decline associated with decreased oxidative phosphorylation in melanin-stained keratinocytes and the attenuated metabolic activity of the pigmentation microenvironment.

[0042] Although the embodiments of the present invention have been described above, the present invention is not limited to these, and the materials used, various conditions, etc. can be changed as appropriate within the scope of the invention.

Claims

1. An agent for suppressing the secretion and / or expression of SASP factors by keratinocytes, comprising one or more active ingredients selected from the group consisting of GK2, TA, 4MSK and analogs thereof.

2. The agent for suppressing the secretion and / or expression of a SASP factor according to claim 1, wherein the SASP factor is GROα (CXCL1).

3. The agent for suppressing the secretion and / or expression of SASP factors according to claim 1, wherein the secretion and / or expression of SASP factors is promoted by excessive accumulation of melanin in keratinocytes.

4. The agent for suppressing the secretion and / or expression of SASP factors according to claim 1, which is effective in improving keratinocyte aging caused by excessive accumulation of melanin.

5. 2. The agent for suppressing the secretion and / or expression of SASP factors according to claim 1, comprising TA and / or an analog thereof and GK2 and / or an analog thereof.

6. 2. The agent for inhibiting the secretion and / or expression of SASP factors according to claim 1, comprising TA and / or an analog thereof and 4MSK and / or an analog thereof.

7. 2. The agent for inhibiting the secretion and / or expression of SASP factors according to claim 1, comprising TA and / or an analog thereof, GK2 and / or an analog thereof, and 4MSK and / or an analog thereof.

8. A keratinocyte metabolism improvement promoter comprising TA and / or an analog thereof, GK2 and / or an analog thereof, and 4MSK and / or an analog thereof.

9. A method for screening for an inhibitor of secretion / expression of SASP factors by keratinocytes, comprising adding a candidate drug to melanin-excessive keratinocytes and culturing the cells, and using the secreted or expressed SASP factors as an indicator.

10. The screening method according to claim 9, wherein the SASP factor is GROα (CXCL1).

11. The screening method according to claim 9, wherein the candidate drug screened as an inhibitor of secretion and / or expression of SASP factors by keratinocytes is a promoter of improvement of keratinocyte metabolism.

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