JP6338107B2 - Skin barrier function improving agent, intercellular adhesion structure formation promoter, tight junction formation promoter, and TRPV4 gene expression enhancer - Google Patents

Description

  The present invention relates to a skin barrier function improving agent, an intercellular adhesion structure formation promoter, a tight junction formation promoter, and a TRPV4 gene expression enhancer.

  It is known that the skin has a function as a barrier that prevents permeation of substances to the outside world and entry of foreign substances, and is called a barrier function in the skin.

  As a barrier function in the skin, the function of the stratum corneum, which is a hydrophobic layer in which dead keratinocytes are embedded in an extracellular nonpolar lipid layer, has been known. It has been known that the function of the inter-bonding structure contributes greatly. As such an intercellular adhesion structure, tight junction (TJ: Tight-junction), adherence junction (AJ: Adherens-junction), etc. are known. Tight junctions and adherence junctions exist in the form of a belt around cells such as keratinocytes, and prevent cells from adhering to each other by adhering adjacent cells together, and continuously connect cells. In particular, tight junctions are present in the epidermal cells of the granule layer and prevent water, substances and foreign substances from penetrating into the cell gap and play an important role in maintaining the skin barrier function. Further, it is known that the normal formation of the adherence junction plays an important role in the formation of the tight junction.

  TRPV4 is known as an important gene for this skin barrier function. TRPV4 is one of nine temperature-sensitive receptors belonging to the TRP (Transient receptor potential) channel of a non-selective cation channel, and functions as a transmembrane calcium influx channel. TRPV4 was originally discovered as an osmotic-sensitive receptor that is activated with low osmotic pressure, and is expressed in various tissues such as skin epidermis cells, sensory nerves, hypothalamus, kidney, lung, inner ear, In addition to temperature stimulation, it plays an important role in the transmission of pain and inflammatory pain due to osmotic pressure stimulation and mechanical stimulation.

So far, for example, the following has been specifically reported on the relationship between TRPV4 and the skin barrier function.
Non-Patent Documents 1 and 2 show that mice in which the TRPV4 gene present in the epidermis is invalidated have an impaired intercellular adhesion structure-dependent barrier, and TRPV4 is a cadherin that is a component of an adherence junction. It is described that this is considered to be involved in the formation of an intercellular adhesion structure, including the promotion of tight junction formation. Non-Patent Document 2 discloses that the formation failure of adherence junction and tight junction at low temperature is cured by the TRPV4 activator, the adhesiveness between cells is increased by activating TRPV4, the stratum corneum It is described that recovery of the decrease in barrier function due to disturbance is promoted by stimulating TRPV4. Non-Patent Document 3 states that the TRPV4 gene is expressed in human epidermal keratinocytes in which tight junctions are formed, and that it is involved in tight junction formation by adding an activator of TRPV4 to keratinocytes. It is described that the amount of protein such as claudin 4 is increased and the paracellular permeability barrier involving tight junction formation in keratinocytes is strengthened.

  Therefore, it is considered that the substance that enhances the gene expression of TRPV4 in the epidermis increases the amount of TRPV4 protein in the epidermis, thereby enhancing the function of improving skin barrier by TRPV4.

Kuzu is a legume plant and has been used as a raw material for edible and traditional Chinese medicine since ancient times. For example, kuzu starch is used as a raw material for Japanese confectionery, and kuzu root and flower are referred to as kuzu root and kuzu flower, respectively. Yes. The effects of kuzuka in relation to the skin include, for example, collagenase inhibitory effect, antioxidant action, elastase inhibitory activity, hyaluronidase inhibitory activity, etc. A flow improving effect, a tyrosinase activity inhibiting effect, a melanin production suppressing effect, an acne prevention and improving effect, etc. are known (Patent Documents 1 to 4).
However, nothing has been known about the defense against infection from the outside world or the skin barrier function of preventing substance permeation.

JP 2006-111541 A JP 2006-249071 A JP 2011-213600 A JP 2011-219462 A

J. Biol. Chem. 2010 June 11; 285: 18749-58 Pflugers Arch. 2012 Apr; 463: 715-25 Skin Pharmacol Physiol. 2013; 26: 15-21

  The subject of the present invention is a highly safe and effective skin barrier function improving agent, an intercellular adhesion structure formation promoter, a tight junction formation promoter, and a TRPV4 gene expression enhancer, which are highly safe when taken orally and percutaneously. Is to provide.

The present invention provides a skin barrier function improving agent containing a processed kuzu flower.
The present invention provides an agent for promoting the formation of an adhesion structure between cells, which contains a kuzu flower treatment product.
The present invention provides a tight junction formation promoter containing a kuzu flower treatment product.
The present invention provides a TRPV4 gene expression enhancer containing a processed kuzuhana product.

  According to the present invention, a highly safe and effective skin barrier function-improving agent, an intercellular adhesion structure formation promoter, a tight junction formation promoter, and a TRPV4 gene expression enhancer that are highly safe when taken orally and percutaneously. Is provided.

FIG. 1 is a graph showing the survival rate of keratinocytes when the media of Examples and Comparative Examples are added. FIG. 2 is a graph showing the expression level of TRPV4 gene in Examples and Comparative Examples.

  Hereinafter, the present invention will be described based on preferred embodiments thereof. The present invention relates to a skin barrier function improving agent, an intercellular adhesion structure formation promoter, a tight junction formation promoter, and a TRPV4 gene expression enhancer. Hereinafter, these agents are collectively referred to as agents of the present invention. The following description applies to any of the agents of the present invention unless otherwise indicated.

  One of the features of the agent of the present invention is that it contains a processed kuzu flower product. Preferably, a kuzu flower treatment product is contained as an active ingredient, more preferably a kuzu flower extract is contained as an active ingredient. Kuzu is a large vine plant of the legume family, and Kuzuhana is the flower part of Kuzu. Kuzuka may include pistils, stamens, sepals, flower axes, coconut leaves, etc. in addition to kuzu petals. In the present invention, the kuzu flowers collected at any stage from the bud to the fully opened flower may be used, or the kuzu flowers collected at a plurality of stages may be mixed and used. In the present invention, it is preferable to use kuzuka at the stage of wrinkles. Examples of the type of kuzu include Pueraria thomsonii, Pueraria lobata, Pueraria thunbergiana, and the like, and one or more of these can be used in combination. In particular, it is preferable to use Pueraria thomsonii.

  In the present specification, the “Kuzuhana processed product” is a processed product of the Kuzuka. The processed kuzuka product is preferably a processed product obtained by subjecting kuzuka to at least one of a drying process, a pulverizing process, and an extraction process. More preferably, it is at least one selected from dried pulverized flowers (hereinafter also referred to as kuzuka powder) and kuzuka extract. The kuzu flower extract here includes an extract obtained by performing an extraction process from kuzu flower itself, a kuzu flower crushed product, a kuzu flower dried product or kuzu flower powder; and a concentrated and / or purified product of the extract. It is. In the present invention, it is preferable to use a kuzu flower extract from the standpoint of the remarkable effect during use and the stability of quality. Examples of the shape of the kuzu flower extract include liquids, pastes, powders, fine granules, and granules.

  Hereinafter, a method for preparing a dried kuzu flower, a kuzu flower powder, and a kuzu flower extract will be described as examples of the kuzu flower processed product.

  The dried kuzu flower can be obtained by drying kuzu flowers by sun drying, hot air drying or the like. The moisture content is preferably dried to 10% by mass or less.

  The kuzu flower powder (dry powder) can be obtained by pulverizing the dried kuzu flower product. The powderization can be performed by a method commonly used by those skilled in the art, for example, a ball mill, a hammer mill, a roller mill, or the like. Alternatively, the Kuzuka powder (dried powder) is obtained by crushing the collected Kuzuka using a mass colloid, slicer, comitolol, etc. to obtain a Kuzuka crushed product, and drying this Kuzuka crushed product. be able to.

  Katsuhana extract is extracted by adding a solvent to Kuzuka, Kuzuka crushed material, Kuzuka dried product, or Kuzuka powder (dry powder), heating as necessary, and centrifuging. Alternatively, it can be obtained by collecting the extract by filtration. The kuzu flower extract is preferably an extract of a kuzu flower dry product or a pulverized product thereof (katsuka powder).

  Examples of the solvent that can be used to obtain the Kuzuhana extract include water, organic solvents, and hydrous organic solvents. Examples of the organic solvent include methanol, ethanol, n-propanol, n-butanol, acetone, hexane, cyclohexane, propylene glycol, ethyl methyl ketone, glycerin, methyl acetate, ethyl acetate, diethyl ether, dichloromethane, edible oils and fats, 1, Examples include 1,1,2-tetrafluoroethane, 1,1,2-trichloroethene and the like. Among these, preferred are polar organic solvents, more preferred are water, ethanol, n-butanol, methanol, acetone, propylene glycol, and ethyl acetate, and most preferred are water and / or ethanol.

  Examples of the extraction method include a warm extraction method and a supercritical extraction method. In these extraction methods, heating may be performed by applying pressure as necessary. When heating, it is necessary to prevent the solvent added to Kuzuka from volatilizing. When heating, the extraction temperature is preferably 50 ° C. or higher, more preferably 70 ° C. or higher, most preferably 90 ° C. or higher, preferably 130 ° C. or lower, more preferably 100 ° C. or lower.

  The extraction time may be a time for sufficiently extracting soluble components from the extraction raw material, and may be set as appropriate according to the extraction temperature and the like. Preferably it is 30 minutes or more and 48 hours or less. For example, when the extraction temperature is less than 50 ° C., it is preferably 6 hours or more and 48 hours or less, and when it is 50 ° C. or more, it is preferably 30 minutes or more and 24 hours or less.

  The obtained extract may be used as a liquid kuzu flower extract as it is. If necessary, the obtained extract may be concentrated by a method used by those skilled in the art, such as vacuum concentration or lyophilization, to obtain a liquid, paste-like or powdered Kuzuka extract. In addition, a powdery kuzu flower extract may be called an extract powder.

  If a preferable aspect is specifically mentioned, 1 mass part or more and 10000 mass parts with respect to 100 mass parts (dry matter conversion) of Kuzuka, Kuzuka crushed material, Kuzuka dried material, or Kuzuka powder (dry powder). The following hot water was mixed to obtain a mixture, and the mixture was heated for 30 minutes to 48 hours while maintaining the temperature at 50 ° C. to 130 ° C. It is preferable that the extract obtained by extraction is filtered by centrifugation and then dried by spray drying to obtain a powdered Kuzuka extract.

  The kuzu flower extract obtained as described above may be contained in the agent of the present invention as it is. Alternatively, the extract of the present invention contains one or more treatments selected from further extraction, concentration, fractionation, separation and purification so as to increase the content of a specific component. You may let them. Examples of the fractionation or purification treatment include treatment using a synthetic adsorbent (Diaion HP20, Sephabies SP825, Amberlite XAD4, MCIgelCHP20P, etc.) and dextran resin (Sephadex LH-20, etc.). By such purification (or fractionation), a kuzu flower extract having a high concentration of the specific component can be obtained.

  The agent of the present invention contains the processed Kuzuka product described above.

  The kuzu flower processed product can be used as various products by taking advantage of the above-mentioned characteristics and by combining the kuzu flower processed product alone or with other components. Such products include various forms of skin cosmetics, transdermal pharmaceuticals or quasi-drugs, baths, detergents such as soaps, shampoos, etc. The form which orally ingests the Kuzuka processed material, such as a composition for oral and oral use. The skin cosmetics herein may be those intended for humans, or may be intended for animals other than humans, particularly mammals. By using the processed kuzuhana product as these products, a desired skin barrier function improving effect can be imparted to these products.

  For example, as the dosage form in the case where the processed Kuzuka product is used as a product of various forms for ingestion through the skin, lotions, emulsions, gels, creams, ointments, powders, granules, capsules, sheets, bubbles, sprays , Aerosols, pastes, packs, etc., any form can be mentioned regardless of liquid form or solid form.

  The specific application field in the case of using the processed kuzuhana product as a product in the form of being ingested through the skin can be used in, for example, various external preparations (including preparations used for animals other than humans) in general, Specifically, ampules, capsules, pills, tablets, powders, granules, solids, liquids, gels, bubbles, emulsions, sheets, mists, sprays, etc. are suitable for use in 1) pharmaceuticals, 2) pharmaceuticals Quasi-drugs, 3) topical or systemic skin cosmetics (for example, basic cosmetics such as lotions, emulsions, creams, ointments, lotions, oils, packs, facial cleansers, skin cleansers, massage agents, Cleansing agent, hair remover, hair remover, shaving treatment, after shave lotion, pre-show lotion, shaving cream, foundation, lipstick, blusher, eye shadow, eyeliner, mass Makeup cosmetics such as LA, perfumes, nail enamels, nail enamels, nail enamel removers, poultices, plasters, tapes, sheets, patches, aerosols, etc.), 4) applied to the scalp Medicinal or / and cosmetic preparations (for example, shampoos, rinses, hair treatments, pre-hair treatments, permanent liquids, hair dyes, hair styling agents, hair styling agents, hair growth / hair restoration agents, poultices, plasters Agent, tape agent, sheet agent, patch agent, aerosol agent, etc.), 5) Bath agent to be used in bath water, 6) Other anti-odor and deodorant agents, deodorant, antiperspirant, hygiene products, Sanitary cotton, wet tissue, mouth freshener, gargle, and the like.

  In the case where the processed kuzuhana product is a product in the form of the above-mentioned various forms of percutaneous ingestion, components other than the processed kuzuka product include oils and fats, waxes, hydrocarbons, fatty acids, water, alcohol , Esters, surfactants, metal soaps, pH adjusters, preservatives, fragrances, moisturizers, powders, UV absorbers, thickeners, pigments, functional ingredients, animal and plant ingredients, antioxidants, chelating agents Any component used as an external preparation can be used without limitation.

  When the agent of the present invention is used in a form to be ingested percutaneously, in the agent of the present invention, the content of the processed kuzuka product described above is the treatment method of the processed kuzuka product, the use of the agent and the dosage form. In general, it is preferably 0.00001 parts by mass or more and preferably 0.0001 parts by mass or more in the solid content of the agent of the present invention, although it varies depending on the difference in intake method and the level of required effect. More preferably, it is more preferably 0.0005 parts by mass or more, and particularly preferably 0.001 parts by mass or more. Further, in the agent of the present invention, the content of the processed kuzuhana product is preferably 40 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 10 parts by mass or less, and further 5 parts by mass. It is particularly preferred that

  In the agent of the present invention, when the processed Kuzuka product is a product of the above-mentioned various forms to be taken orally, the dosage form of the product is, for example, powder, granule, granule, tablet, rod, plate, Examples of the shape include a block shape, a solid shape, a round shape, a liquid shape, a paste shape, a cream shape, a capsule shape such as a hard capsule and a soft capsule, a caplet shape, a tablet shape, and a gel shape.

When the agent of the present invention is a product in the form of various oral intakes, the other components include, for example, various skin barrier function improving agents other than the processed Kuzuka product, for example, vitamins (A, C, D, E, K, folic acid, pantothenic acid, biotin, derivatives thereof, etc.), minerals (iron, magnesium, calcium, zinc, selenium, etc.) may be blended. Various excipients, binders, lubricants, stabilizers, diluents, extenders, thickeners, emulsifiers, colorants, additives, and the like may be blended.
The content of other components can be appropriately selected according to the dosage form of the agent of the present invention, the level and content of the required effect, and the like.

  When the agent of the present invention is used in a form to be taken orally, in the agent of the present invention, the content of the processed kuzuka product described above is the processing method of the processed kuzuka product, the use and dosage form of the agent, Generally, it is preferably 0.001 part by mass or more and more preferably 0.005 part by mass or more in the solid content of the agent of the present invention, although it varies depending on the difference in intake method and the level of required effect. The amount is more preferably 0.01 parts by mass or more, and particularly preferably 0.1 parts by mass or more.

  When the agent of the present invention is taken orally, the oral dose is preferably about 0.01 g or more and 30 g or less per day for an adult in terms of dry matter of the Kuzuka treatment product, and 0.1 g or more and 10 g. The following is more preferable.

The agent of the present invention enhances TRPV4 gene expression in the epidermis, particularly keratinocytes, which are closely related to the barrier function of the skin, as will be apparent from the description of Examples described later. Thereby, the agent of the present invention can enhance the function of TRPV4 in the epidermis by increasing the amount of TRPV4 protein in keratinocytes, and promote the formation of an intercellular adhesion structure such as tight junction in the epidermis, Skin barrier functions such as a paracellular permeability barrier in keratinocytes can be enhanced. In particular, the skin barrier function targeted by the agent of the present invention is not only a function of permeable to substances such as moisture, but also against the invasion of pathogens into the body, leading to the prevention and improvement of skin disorders such as skin infections. Is. Non-Patent Document 2 described above shows that the expression of TRPV4 is involved not only in the formation of intercellular adhesion structures such as tight junctions but also in the stratum corneum-dependent barrier function. It is well known to function as an antibacterial shield (for example, “Skin Barrier Function and Infection Protection”, JSHI Journal: 119 (11) 2141-2149, 2009). In addition, as described above, the tight junction of the skin promoted by activation of TRPV4 is considered to prevent the antigen that has passed through the stratum corneum from entering the body through the gap between cells. (Www.keio.ac.jp/en/press_release/2009/...att/091203_1.pdf, retrieved on September 16, 2014). Accordingly, the agent of the present invention enhances the gene expression of TRPV4, that is, enhances the expression of this protein, thereby enhancing the barrier function of the skin against pathogens, physical stimuli and foreign substances. It can prevent direct damage and allergic reaction due to the invasion of harmful substances, and can be used for prevention and improvement of skin disorders such as skin infections, atopic dermatitis and sebum deficiency eczema . The agent of the present invention may be used for humans and animals other than humans (such as mammals).
Moreover, since the agent of the present invention shows no toxicity even when applied to cells at a relatively high concentration, as will be apparent from the description of Examples described later, it is highly safe when percutaneously and orally ingested.

  Furthermore, the agent of the present invention, when taken orally, in addition to the various effects described above, improves symptoms such as antipyretic, analgesic, antispasmodic, sweating, liver damage improving effect, liver lipid accumulation inhibitory effect, Known effects such as hangover prevention effect, urine nitrogen metabolism improvement, body fat reduction effect, anti-obesity effect, blood flow improvement effect, etc. can be obtained.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. Hereinafter, unless otherwise specified, “%” represents mass%, and “part” represents mass part. Note that the media and samples described below were appropriately sterilized as necessary.

[Example 1]
As a kuzu flower processed product, a powdery kuzu flower extract was used. This kuzu flower extract was obtained by hot water extraction of a dry powder of kuzu flower (Puellaria tomsonii, site: petal) collected at the stage of cocoon. This kuzu flower extract was dissolved in DMSO to a concentration of 0.4 mg / mL, and then further diluted 1000 times with Keratinocyte Basal Medium (DMSO final concentration 0.1%) to obtain the test substance-containing medium of Example 1 It was. Keratinocyte Basal Medium is obtained by adding 1 part each of the attached supplement and Penicillin-Streptomycin to 100 parts of the medium in Keratinocyte Basal Medium 2 Kit manufactured by Takara Bio (Promo Cell). Abbreviated.

[Examples 2 to 4]
A test substance-containing medium was obtained in the same manner as in Example 1 except that a DMSO solution having a Kuzuka extract concentration of 2 mg / mL, 10 mg / mL, and 50 mg / mL was diluted 1000-fold with KBM. .

[Comparative Example 1]
KBM containing 0.1% DMSO was used.

The culture media prepared in Examples 1 to 4 and Comparative Example 1 were subjected to the following <survival rate test>.
<Survival test>
(1) Cell Culture Normal human epidermal keratinocytes (adult, pooled, manufactured by PromoCell, passage number P7-9, hereinafter abbreviated as “NHEK cells”) were cultured according to the following procedure.

NHEK cells were cultured with KBM in a 75 cm ² flask in a 37 ° C., 5% CO ₂ incubator. NHEK cells after culture were suspended by Trypsin-EDTA treatment. 1 ml of the suspended cell-containing medium was seeded on a 24-well plate at 5 × 10 ⁴ cells / well. NHEK cells in wells were pre-cultured for 24 hours in a 37 ° C., 5% CO ₂ incubator.

After the preculture, the medium was removed, and then 1 mL / well of each of the test substance-containing media prepared in Examples 1 to 4 was added and cultured for 48 hours in a 37 ° C., 5% CO ₂ incubator (n = 3). As negative control, the culture medium of Comparative Example 1 was used instead of the culture medium of Example 1, and the same culture was performed.

(2) Measurement of survival rate The culture medium supernatant was removed from each well after cell culture. Next, the cells in the wells were washed twice with 1 mL / well of Dulbecco's phosphate buffered saline (hereinafter abbreviated as PBS). Cell Counting Kit-8 (Dojindo Laboratories) diluted 30 times with serum-free Dulbecco's Modified Eagle's Medium (hereinafter abbreviated as DMEM) was prepared, and this was added to the washed cells at 500 μL / well. After leaving the plate in a 37 ° C., 5% CO ₂ incubator, 100 μL was transferred to a 96-well plate, and the absorbance at 450 nm was measured with a plate reader (VARIOSKAN, manufactured by Thermo electron). Based on the obtained absorbance, the ratio (% of control) to the negative control was calculated from the following formula, and this average value was defined as the cell viability. The obtained cell viability is shown in FIG.
% of Control = (Data sample−Data blank) / (Data control−Data blank) × 100

  From the results of FIG. 1, it can be seen that the media of Examples 1 to 4 containing the processed kuzuka product have no cytotoxicity regardless of the concentration.

  The NHEK cells cultured in the above (1) using the medium of Example 1 and Comparative Example 1 were subjected to the following <Gene expression analysis test>.

<Gene expression analysis test>
(A) mRNA extraction (using QIAGEN RNeasy Mini Kit)
After culturing the cells as in (1) cell culture of <viability test>, the medium supernatant was removed from each well and washed twice with PBS 1 mL / well. Next, Buffer RLT was added at 350 μL / well and shaken at room temperature for 5 minutes. After shaking, 350 μL of 70% ethanol was added to each well and mixed by pipetting. Thereafter, the entire solution in each well was added to the RNeasy spin column and set in a 2 mL collection tube. Thereafter, a total RNA sample was obtained by the procedure according to the protocol attached to the RNeasy Mini Kit.

(B) Preparation of cDNA (using Reverse Transcription Kit from QIAGEN)
The concentration and purity (260 nm / 280 nm) of the RNA sample extracted in (A) were measured using NanoDrop manufactured by Thermo electron. In order to remove genomic DNA, 300 ng of template RNA, 2 μL of gDNA Wipeout Buffer, and RNase free water were mixed in a 1.5 mL sterile tube on ice to make a total volume of 14 μL. After incubating at 42 ° C for 2 minutes, it was transferred to ice. To this tube, 6 μL of a mixed solution in which Quantiscript Reverse Transcriptase: Quantiscript RT Buffer: RT Primer Mix was mixed at a ratio of 1: 4: 1 was dispensed. After incubation at 42 ° C for 15 minutes, the mixture was incubated at 95 ° C for 3 minutes and stored at -80 ° C.

(C) Implementation of RT-PCR
The cDNA sample prepared in (B) was diluted 10-fold with RNase free water and used as a template. In order to prepare a calibration curve, one sample was diluted 10 times and then further diluted 4 times and 16 times. The diluted cDNA was dispensed at 4 μL each into a 0.1 mL tube on ice. To this tube, 6 μL of the mixed solution mixed at a ratio of PCR Mix: Primer = 5: 1 was dispensed. RT-PCR was performed on the cDNA in the tube under the following conditions. Primer used the following.

(RT-PCR conditions)
Hold: 95 ℃, 5 minutes
Cycle: 95 ℃ ・ 5 seconds → 60 ℃ ・ 10 seconds × 40 cycle
Melt: 55-99 ℃

(Primer)
-GAPDH: Hs_GAPDH_2_SG (QT01192646)
・ TRPV4: Hs_TRPV4_1_SG (QT00077217)

  The gene expression level in each sample was calculated using a calibration curve prepared from samples diluted 1-fold (10-fold dilution of cDNA sample), 4-fold, and 16-fold. MRNA amount was corrected using GAPDH (housekeeping gene) as an internal standard, and the gene expression level relative to negative control was calculated. The result is shown in FIG. The * in FIG. 2 indicates that the expression level of Example 1 was significantly different from that of Comparative Example 1 with a risk factor p <0.05 by t-test.

  From the results shown in FIG. 2, it can be seen that the expression level of the TRPV4 gene was significantly increased in Example 1 using the processed kuzuhana product compared to Comparative Example 1 not using the processed kuzuka product. From this result, the agent of the present invention containing the processed kuzuka product is useful as an agent for enhancing the expression of TRPV4 gene, and also has the effect of enhancing the expression of TRPV4, thereby improving the skin barrier function and the intercellular adhesion structure. It is apparent that the present invention is also effective as a formation accelerator and a tight junction formation accelerator.

Claims (3)

  An agent for promoting the formation of an intercellular adhesion structure, comprising a processed kuzuhana product.   Tight junction formation accelerator containing a kuzu flower treatment product. A TRPV4 gene expression enhancer containing a processed kuzuhana product.