ELOVL4 gene expression reduction inhibitor

Abstract

To provide a novel technology for suppressing the decrease in ELOVL4 gene expression caused by psychological stress. [Solution] The present invention provides an ELOVL4 gene expression inhibitor and a skin barrier function improving agent, each containing one or more substances selected from tea extract, perilla extract, mallow extract, and nettle extract. The ELOVL4 gene expression inhibitor and skin barrier function improving agent according to this technology can be used in cosmetics and topical skin preparations.

Description

Technical Field

[0001] The present invention relates to an agent for suppressing the decrease in ELOVL4 gene expression.

Background Art

[0002] The skin barrier function plays an important role in preventing harmful substances such as allergens and pathogenic microorganisms such as pollen from entering the body, and maintaining moisture by preventing water evaporation from the inside of the skin. Among them, the intercellular lipids in the stratum corneum are an important element that plays a part in filling the intercellular space of the stratum corneum on the outermost surface of the skin.

[0003] It is already known that a decrease in the barrier function affects the predisposition to atopic dermatitis in which skin conditions such as dryness and inflammation are observed. On the other hand, since a decrease in the barrier function can occur in healthy individuals due to various external and internal factors, it is important to maintain a good state of the barrier function in order to maintain a healthy skin condition.

[0004] The main components of intercellular lipids that play an important role in the barrier function are ceramide, cholesterol, and free fatty acids. In order to fully exert the barrier function, there are means to promote the production of components including ceramide, but at the same time, it is also important to extend the chain length of the fatty acid moieties of ceramide and free fatty acids.

[0005] For example, Non-Patent Document 1 discloses that in the lesional skin of patients with atopic dermatitis, the proportion of long-chain fatty acids having 24 or more carbon atoms among all free fatty acids in the intercellular lipids is lower than that of healthy individuals, and the trans-epidermal water loss (TEWL) tends to be higher. As an enzyme that extends the chain length of the fatty acid moieties of ceramide and free fatty acids, ELOVL is known, and it is known that ELOVL4 shows high activity particularly for fatty acids having a chain length of 24 or more carbon atoms.

[0006] Furthermore, for example, Non-Patent Document 2 discloses that in mice in which ELOVL4 function is lost, long-chain ceramides and fatty acids decrease, and the barrier function does not work properly. Therefore, it is thought that promoting ELOVL4 production is effective in extending the chain length of ceramides and free fatty acids and enhancing barrier function, and for example, Patent Document 1 discloses an ELOVL4 production promoter containing Houttuynia cordata, etc. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-022995 [Non-patent literature]

[0008] [Non-Patent Document 1] Jeroen van Smeden et al., Experimental Dermatology, 2014, 23, 45-52 [Non-Patent Document 2] Vidyullatha Vasireddy et al., Human Molecular Genetics, 2007, Vol. 16, No. 5, 471-482 [Overview of the project] [Problems that the invention aims to solve]

[0009] As mentioned above, development of technologies related to the expression of the ELOVL4 gene is progressing, but the technology described in Patent Document 1 is a technology that promotes the expression of the ELOVL4 gene. On the other hand, the present inventors have discovered that psychological stress reduces the expression of the ELOVL4 gene. Therefore, the main objective of this technology is to provide a novel technology for suppressing the decrease in ELOVL4 gene expression caused by psychological stress. [Means for solving the problem]

[0010] The inventors diligently searched for substances that are effective in suppressing the decrease in ELOVL4 gene expression caused by psychological stress. They discovered that extracts from tea plant (Camellia sinensis), perilla (Perilla frutescens var. crispa), mallow (Malva mauritiana L.), and nettle (Urtica thunbergiana) have the effect of suppressing the decrease in ELOVL4 gene expression caused by psychological stress and improving skin barrier function, thus completing this technology.

[0011] In other words, this technology provides the following: [1] A barrier function improving agent containing one or more selected from the group consisting of tea extract, perilla extract, mallow extract, and nettle extract. [2] An ELOVL4 gene expression reduction inhibitor containing one or more selected from the group consisting of tea extract, perilla extract, mallow extract, and nettle extract. [3] The ELOVL4 gene expression reduction inhibitor described in 2, wherein the reduction in ELOVL4 gene expression is caused by psychological stress. [4] The barrier function improving agent according to 1, wherein the tea extract is an extract of unfermented tea, or the ELOVL4 gene expression reduction inhibitor according to 2 or 3. [5] A composition containing a barrier function improving agent or an ELOVL4 gene expression reduction inhibitor as described in any of 1 to 4. [6] The composition according to 5, which is a cosmetic or a topical skin preparation. [7] A screening method for skin barrier function improving components under psychological stress, using ELOVL4 gene expression levels as an indicator. [Effects of the Invention]

[0012] This technology provides a novel method for suppressing the decrease in ELOVL4 gene expression. However, the effects of this technology are not limited to those described herein, and may include any of the effects described in this specification.

Brief Description of the Drawings

[0013] [Figure 1] It is a graph of the expression level of the ELOVL4 gene. By adding an extract of Malva mauritiana L. or Perilla frutescens var. crispa, the decrease in the expression level of the ELOVL4 gene was suppressed. By adding an extract of apple or European beech buds, no decrease in the expression level of the ELOVLE4 gene was observed. [Figure 2] It is a graph of the expression level of the ELOVL4 gene. By adding an extract of Gyokuro or Urtica thunbergiana, the decrease in the expression level of the ELOVL4 gene was suppressed.

Modes for Carrying Out the Invention

[0014] Hereinafter, preferred embodiments for implementing the present technology will be described. The embodiments described below show typical embodiments of the present technology, and the scope of the present technology is not limited only to these embodiments.

[0015] 1. Inhibitor of ELOVL4 gene expression reduction, skin barrier function improver The inhibitor of ELOVL4 gene expression reduction and the skin barrier function improver according to the present technology contain one or more substances selected from extracts of Camellia sinensis, Perilla frutescens var. crispa, Malva mauritiana L., and Urtica thunbergiana.

[0016] (1) Extract of Camellia sinensis Camellia sinensis is a plant belonging to the genus Camellia of the family Theaceae, and its scientific name is Camellia sinensis. The extract of Camellia sinensis is an extract obtained by extracting the roots, stems, leaves, branches, flowers, fruits, etc. of Camellia sinensis with an appropriate solvent, and usually, a concentrated solution of the extracted solvent is used. Also, a freeze-dried product of the concentrated solution can be used in the present technology.

[0017] The specific extraction site of Camellia sinensis is not particularly limited as long as the object of the present technology is not impaired, but it is preferable to select leaves or stems, and more preferably to select leaves. Further, the extraction site may be immediately after collection, or may be used for extraction after drying. If necessary, it can also be used for extraction after performing processing such as pulverization, cutting, shredding, and shaping.

[0018] The Camellia sinensis used for extraction may be subjected to extraction such as fermented teas such as black tea and Pu-erh tea, semi-fermented teas such as oolong tea and Baozhong tea, non-fermented teas such as green tea, kettle-boiled green tea, and roasted green tea. From the viewpoint of the excellent inhibitory effect on the decrease in ELOVL4 gene expression, it is preferable to subject non-fermented tea to extraction, and more preferably to subject green tea to extraction.

[0019] The green tea used in the present technology is tea that has not fermented the leaves of Camellia sinensis. Green tea varies depending on the variety, production area, manufacturing method, etc., and gyokuro, sencha, new tea, kabusecha, powdered tea, roasted green tea, matcha, sayamacha, uji tea, longjing tea, biluochun, etc. are known. Among these, the one obtained by covering the tea leaves before harvesting to block sunlight and increasing amino acids is called gyokuro. From the viewpoint of the excellent inhibitory effect on the decrease in ELOVL4 gene expression, gyokuro is preferable.

[0020] The solvent used for extraction is not particularly limited, and usually, one or more solvents that can be used for plant extraction can be freely selected and used. For example, water, alcohols, glycols, ketones, esters, ethers, halogenated carbons, supercritical solvents (such as carbon dioxide), subcritical solvents, etc. can be mentioned. Examples of alcohols include ethanol, methanol, and propanol. Examples of glycols include ethylene glycol, diethylene glycol, butylene glycol, and propylene glycol. Examples of ketones include acetone and methyl ethyl ketone. Examples of esters include ethyl acetate, propyl acetate, and ethyl formate. These solvents may be used alone or as an aqueous solution, or may be used as an arbitrary mixed solvent of two or more or three or more. In the present technology, among these, it is particularly preferable to use ethanol.

[0021] In this technology, when ethanol is used as the extraction solvent, its concentration is not particularly limited, but it is preferably 100% by mass or less, and more preferably 90% by mass or less. Furthermore, from the viewpoint of extraction efficiency, it is preferably 50% by mass or more, and particularly preferably 70% by mass or more.

[0022] The extraction method is not particularly limited, and any extraction method commonly used in plant extraction can be freely selected and used. For example, one method involves immersing the leaves of the tea plant in the solvent for 24 hours and then filtering, or extracting while heating and stirring at a temperature below the boiling point of the solvent and then filtering.

[0023] The tea extract can be used as is as an active ingredient in the ELOVL4 gene expression inhibitor and skin barrier function improver related to this technology. However, it is also possible to further fractionate the extract to obtain a highly active fraction using appropriate separation methods (e.g., partition extraction, gel filtration, silica gel chromatography, reverse-phase or normal-phase high-performance liquid chromatography, etc.). (2) Perilla extract Perilla (Shiso) is a plant belonging to the genus Perilla in the family Lamiaceae, and its scientific name is Perilla frutescens var. crispa. Perilla extract is obtained by extracting the roots, stems, leaves, branch tips, flowers, and fruits of Perilla frutescens var. crispa with a suitable solvent, and usually a concentrated solution of the extracted solvent is used. Freeze-dried versions of this concentrated solution can also be used in this technology.

[0024] The specific part of the perilla plant used for extraction is not particularly limited as long as it does not impair the purpose of this technology, but it is preferable to select leaves or branch tips, and more preferably leaves. The extraction part may be used immediately after harvesting, or it may be dried before use. If necessary, it may also be processed by crushing, cutting, shredding, shaping, etc., before use for extraction.

[0025] The solvent used for extraction is not particularly limited, and one or more solvents that can normally be used for plant extraction can be freely selected and used. Examples include water, alcohols, glycols, ketones, esters, ethers, carbon halides, supercritical solvents (such as carbon dioxide), and subcritical solvents. Examples of alcohols include ethanol, methanol, and propanol. Examples of glycols include ethylene glycol, diethylene glycol, butylene glycol, and propylene glycol. Examples of ketones include acetone and methyl ethyl ketone. Examples of esters include ethyl acetate, propyl acetate, and ethyl formate. These solvents may be used individually or as aqueous solutions, or as a mixture of any two or three or more solvents. In this technology, the use of butylene glycol is particularly preferred.

[0026] In this technology, when butylene glycol is used as the extraction solvent, its concentration is not particularly limited, but is preferably 90% by mass or less, and more preferably 70% by mass or less. Furthermore, from the viewpoint of extraction efficiency, it is preferably 30% by mass or more, and particularly preferably 50% by mass or more.

[0027] The extraction method is not particularly limited, and any extraction method commonly used in plant extraction can be freely selected and used. For example, one method is to immerse any part of the perilla plant in the solvent for 24 hours and then filter it, or to extract the material while heating and stirring at a temperature below the boiling point of the solvent and then filter it.

[0028] The extract of perilla can be used as is as an active ingredient in the ELOVL4 gene expression inhibitor and skin barrier function improver related to this technology. However, it is also possible to further fractionate the extract to obtain a highly active fraction using appropriate separation methods (e.g., partition extraction, gel filtration, silica gel chromatography, reverse-phase or normal-phase high-performance liquid chromatography, etc.). (3) Mallow extract Malva mauritiana L. is a plant belonging to the Malvaceae family, genus Malva, and is sometimes called common mallow. Its scientific name is Malva mauritiana L. Malva mauritiana extract is obtained by extracting the roots, stems, leaves, branches, flowers, and fruits of Malva mauritiana L. with a suitable solvent, and usually a concentrated solution of the extracted solvent is used. Freeze-dried versions of this concentrate can also be used in this technology.

[0029] The specific part of the mallow plant used for extraction is not particularly limited as long as it does not impair the purpose of this technology, but it is preferable to select the stem, leaves, or flowers. The extraction part may be used immediately after harvesting, or it may be dried before extraction. If necessary, it may also be processed by crushing, cutting, shredding, shaping, etc., before extraction.

[0030] The solvent used for extraction is not particularly limited, and one or more solvents that can normally be used for plant extraction can be freely selected and used. Examples include water, alcohols, glycols, ketones, esters, ethers, carbon halides, supercritical solvents (such as carbon dioxide), and subcritical solvents. Examples of alcohols include ethanol, methanol, and propanol. Examples of glycols include ethylene glycol, diethylene glycol, butylene glycol, and propylene glycol. Examples of ketones include acetone and methyl ethyl ketone. Examples of esters include ethyl acetate, propyl acetate, and ethyl formate. These solvents may be used individually or as aqueous solutions, or as a mixture of any two or three or more solvents. In this technology, the use of butylene glycol is particularly preferred.

[0031] In this technology, when butylene glycol is used as the extraction solvent, its concentration is not particularly limited, but is preferably 100% by mass or less, and more preferably 70% by mass or less. Furthermore, from the viewpoint of extraction efficiency, it is preferably 30% by mass or more, and particularly preferably 50% by mass or more.

[0032] The extraction method is not particularly limited, and any extraction method commonly used in plant extraction can be freely selected and used. For example, one method is to immerse any part of the mallow plant in the solvent for 24 hours and then filter it, or to extract the material while heating and stirring at a temperature below the boiling point of the solvent and then filter it.

[0033] While the extract of mallow can be used as is as an active ingredient in the ELOVL4 gene expression inhibitor and skin barrier function improver related to this technology, it is also possible to further fractionate the extract to obtain a highly active fraction using appropriate separation methods (e.g., partition extraction, gel filtration, silica gel chromatography, reverse-phase or normal-phase high-performance liquid chromatography, etc.). (4) Nettle extract Nettle (Urtica thunbergiana) is a plant belonging to the Urticaceae family, genus Urtica, and is sometimes called painful nettle. Its scientific name is Urtica thunbergiana. Nettle extract is an extract obtained by extracting the roots, stems, leaves, flowers, and fruits of nettle (Urtica thunbergiana) with a suitable solvent, and usually a concentrated solution of the extracted solvent is used. Freeze-dried versions of this concentrated solution can also be used in this technology.

[0034] The specific part of the nettle used for extraction is not particularly limited as long as it does not impair the purpose of this technology, but it is preferable to select the leaves or flowers, and more preferably the leaves. The extraction part may be used immediately after harvesting, or it may be dried before extraction. If necessary, it may also be processed by crushing, cutting, shredding, molding, etc., before use for extraction.

[0035] The solvent used for extraction is not particularly limited, and one or more solvents that can normally be used for plant extraction can be freely selected and used. Examples include water, alcohols, glycols, ketones, esters, ethers, carbon halides, supercritical solvents (such as carbon dioxide), and subcritical solvents. Examples of alcohols include ethanol, methanol, and propanol. Examples of glycols include ethylene glycol, diethylene glycol, butylene glycol, and propylene glycol. Examples of ketones include acetone and methyl ethyl ketone. Examples of esters include ethyl acetate, propyl acetate, and ethyl formate. These solvents may be used individually or as aqueous solutions, or as a mixture of any two or three or more solvents. In this technology, the use of butylene glycol is particularly preferred.

[0036] In this technology, when butylene glycol is used as the extraction solvent, its concentration is not particularly limited, but is preferably 90% by mass or less, and more preferably 70% by mass or less. Furthermore, from the viewpoint of extraction efficiency, it is preferably 30% by mass or more, and particularly preferably 50% by mass or more.

[0037] The extraction method is not particularly limited, and any extraction method commonly used in plant extraction can be freely selected and used. For example, one method involves immersing any part of the nettle in the solvent for 24 hours and then filtering, or extracting while heating and stirring at a temperature below the boiling point of the solvent and then filtering.

[0038] While nettle extract can be used as is as an active ingredient in the ELOVL4 gene expression inhibitor and skin barrier function improver related to this technology, it is also possible to further fractionate the highly active fraction from the extract using appropriate separation methods (e.g., partition extraction, gel filtration, silica gel chromatography, reverse-phase or normal-phase high-performance liquid chromatography, etc.) before use.

[0039] The dry solid content concentration of the extracts of tea, perilla, mallow, and nettle used in the ELOVL4 gene expression inhibitor and skin barrier function improver related to this technology can be freely set according to the type of extraction solvent and extraction method used, as long as the effects of this technology are not impaired. In particular, the lower limit of the dry solid content concentration can be, for example, 0.00001% by mass or more, preferably 0.0001% by mass or more, and more preferably 0.0004% by mass or more. By setting the lower limit of the dry solid content concentration within this range, a higher ELOVL4 gene expression inhibitory effect and / or skin barrier function improving effect can be achieved. Furthermore, the upper limit of the dry solid content concentration can be, for example, 1% by mass or less, preferably 0.1% by mass or less, and more preferably 0.005% by mass or less. By setting the upper limit of the dry solid content concentration within this range, the generation of plant-derived odors and precipitation can be prevented.

[0040] (5) Others The ELOVL4 gene expression inhibitor and skin barrier function improving agent related to this technology may contain one or more other ingredients that can be freely selected and used in the field of cosmetics and topical skin preparations, as long as they do not impair the effects of this technology. For example, ingredients such as preservatives, emulsifiers, pH adjusters, colorants, antiseptics, and surfactants can be used.

[0041] 2. Psychological stress The psychological stress related to this technology is not particularly limited to any factor that causes tension in one's mind, but refers to stress hormones such as adrenaline, noradrenaline, and acetylcholine that are secreted from the autonomic nervous system center when the body is exposed to psychological stress, and in particular refers to adrenaline.

[0042] 3. Cosmetics The ELOVL4 gene expression inhibitor and skin barrier function improving agent related to this technology can be suitably used in all forms of cosmetics by utilizing their excellent tight junction formation promoting effect and / or skin barrier function improving effect. For example, it can be applied to skincare cosmetics such as lotions, emulsions, creams, serums, and face masks; makeup cosmetics such as foundations, concealers, makeup bases, lipsticks, blushes, eyeshadows, and eyeliners; and sunscreens. Examples of cosmetic formulations include water-based, oil-based, soluble, and emulsion types (O / W, W / O, W / O / W, O / W / O).

[0043] In addition to the ELOVL4 gene expression inhibitor and skin barrier function improving agent related to this technology, the cosmetic composition may contain one or more ingredients that can be freely selected and used in ordinary cosmetics. For example, it may contain all additives that can be commonly used in the field of cosmetics, such as base materials, preservatives, emulsifiers, colorants, antiseptics, surfactants, UV absorbers, antioxidants, humectants, fragrances, antifungal agents, extender pigments, coloring pigments, alcohol, and water.

[0044] Furthermore, because the ELOVL4 gene expression inhibitor and skin barrier function improving agent related to this technology are derived from natural ingredients, there is little need to be careful when using them in combination with other active ingredients. Therefore, in addition to the ELOVL4 gene expression inhibitor and skin barrier function improving agent related to this technology, other active ingredients can be freely added to cosmetics as needed.

[0045] In the cosmetic composition relating to this technology, the content of the ELOVL4 gene expression inhibitor and the skin barrier function improving agent is not particularly limited and can be freely set according to the purpose. In this technology, the content of the dry solids of the tea extract, perilla extract, mallow extract, or nettle extract in the cosmetic composition can be, for example, 0.00001% by mass or more, preferably 0.0001% by mass or more, and more preferably 0.0004% by mass or more. By setting the lower limit of the dry solids concentration within this range, a higher ELOVL4 gene expression inhibitory effect and / or skin barrier function improving effect can be achieved. Furthermore, the upper limit of the dry solids concentration can be, for example, 1% by mass or less, preferably 0.1% by mass or less, and more preferably 0.005% by mass or less. By setting the upper limit of the dry solids concentration within this range, the generation of plant-derived odors and precipitation can be prevented.

[0046] Cosmetics using the cosmetic formulations described above are highly safe and can be used continuously for extended periods because their active ingredients are derived from natural sources.

[0047] 4. Pharmaceuticals, quasi-drugs, and food products The ELOVL4 gene expression inhibitor and skin barrier function improving agent related to this technology can be suitably used in pharmaceuticals, quasi-drugs, and foods by utilizing their excellent tight junction formation promoting effect and / or skin barrier function improving effect. Pharmaceuticals and quasi-drugs can be formulated into desired dosage forms as appropriate, depending on the method of administration, such as oral or parenteral administration, and the dosage form is not particularly limited. For oral administration of pharmaceuticals, for example, they can be formulated into solid preparations such as powders, granules, tablets, lozenges, and capsules; and liquid preparations such as solutions, syrups, suspensions, and emulsions. For parenteral administration, for example, they can be formulated into topical skin preparations, suppositories, vaginal tablets, inhalants, nasal sprays, and injections. For quasi-drugs, for example, they can be formulated into powders, granules, tablets, lozenges, capsules, liquid preparations, syrups, topical skin preparations, ointments, and aerosols. With regard to pharmaceuticals and quasi-drugs, this technology particularly prefers to formulate them into dosage forms for topical skin preparations. Examples of topical skin preparations include topical liquids, topical gels, creams, ointments, sprays, liniments, lotions, poultices, plasters, sprays, aerosols, and patches. As for food products, they can take any form, including frozen foods, powders, sheets, bottles, cans, retort pouches, capsules, and tablets, as well as processed forms such as natural liquid foods, semi-digested nutritional foods, elemental nutritional foods, and drinks containing, for example, proteins, sugars, fats, trace elements, vitamins, emulsifiers, and flavorings. Furthermore, the types of food products are not particularly limited and include, for example, candies, chewing gum, and beverages.

[0048] Pharmaceuticals, quasi-drugs, and food products relating to this technology may contain one or more pharmacologically acceptable additives, which can be freely selected. For example, when pharmaceuticals and quasi-drugs relating to this technology are applied to topical skin preparations, they may contain all additives that are commonly used in the field of pharmaceutical and quasi-drug formulations, such as bases, surfactants, preservatives, emulsifiers, colorants, deodorizers, fragrances, stabilizers, antiseptics, antioxidants, lubricants, solubilizers, and suspending agents.

[0049] The ELOVL4 gene expression inhibitor and skin barrier function improving agent related to this technology have naturally derived active ingredients, thus requiring little caution when used in combination with other drugs. Therefore, it is possible to freely select one or more existing drugs and combine them into a single agent. For example, any drug such as antibacterial agents, anti-inflammatory analgesics, steroids, antifungal agents, antitussives, antihistamines, vitamins, and antitumor agents can be combined. Furthermore, ingredients that have preventive, ameliorative, and / or therapeutic effects on diseases and symptoms that are already known or may be discovered in the future can be used in combination as appropriate, as long as they do not impair the effects of this technology.

[0050] In pharmaceuticals, quasi-drugs, and foods relating to this technology, the content of the ELOVL4 gene expression inhibitor and the skin barrier function improving agent is not particularly limited and can be freely set according to the purpose. In this technology, the content of the dry solids of tea extract, perilla extract, mallow extract, or nettle extract in pharmaceuticals, quasi-drugs, and foods can be, for example, 0.00001% by mass or more, preferably 0.0001% by mass or more, and more preferably 0.0004% by mass or more. By setting the lower limit of the dry solids concentration within this range, a higher ELOVL4 gene expression inhibitory effect and / or skin barrier function improving effect can be achieved. Furthermore, the upper limit of the dry solids concentration can be, for example, 1% by mass or less, preferably 0.1% by mass or less, and more preferably 0.005% by mass or less. By setting the upper limit of the dry solids concentration within this range, the generation of plant-derived odors and precipitation can be prevented.

[0051] The pharmaceuticals, quasi-drugs, and food products related to this technology, as described above, have active ingredients derived from natural sources, making them highly likely to be safe for administration to patients suffering from various diseases. Furthermore, the likelihood of side effects is low even with long-term, continuous administration.

[0052] 5. A screening method for skin barrier function improving components under psychological stress, using ELOVL4 gene expression levels as an indicator. The present technology provides a screening method for components that improve skin barrier function under psychological stress, using ELOVL4 gene expression levels as an indicator. This method includes a step of providing a prepared test substance to normal human epidermal keratinocytes and determining whether the test substance is useful in improving skin barrier function, using the ELOVL4 gene expression level after the addition of adrenaline as an indicator. [Examples]

[0053] The present technology will be described in more detail below based on the following examples. The examples described below are representative examples of the present technology and should not be interpreted as narrowing the scope of the present technology.

[0054] <Preparation of Gyokuro Extract> Dried and pulverized gyokuro tea leaves were placed in an extraction solvent, and the leaf components were extracted. After removing insoluble matter by filtration, the solid content was adjusted with the solvent to obtain tea extract. Aqueous ethanol (ethanol concentration: 80 vol%) was used as the extraction solvent.

[0055] <Preparation of Perilla Extract> Dried and pulverized perilla leaves were placed in an extraction solvent, and the leaf components were extracted. After removing insoluble matter by filtration, the solid content was adjusted with the solvent to obtain perilla extract. Aqueous 1,3-butylene glycol (1,3-butylene glycol concentration: 50 vol%) was used as the extraction solvent.

[0056] <Preparation of Mallow Extract> Dried and pulverized mallow leaves, stems, and flowers were placed in an extraction solvent. After extracting the leaf components, insoluble matter was removed by filtration, and the solid content was adjusted with the solvent to obtain a mallow extract. 1,3-butylene glycol (1,3-butylene glycol concentration: 100 vol%) was used as the extraction solvent.

[0057] <Preparation of nettle extract> Dry, pulverized nettle leaves were placed in an extraction solvent to extract the leaf components. After removing insoluble matter by filtration, the solid content was adjusted with the solvent to obtain a nettle extract. The extraction solvent used was aqueous 1,3-butylene glycol (1,3-butylene glycol concentration: 50 vol%).

[0058] <Example of experiment> In the experiment, we investigated the inhibitory effect of extracts from gyokuro tea, perilla, mallow, and nettle on the decrease in ELOVL4 gene expression caused by the addition of stress hormones (adrenaline).

[0059] (1) Quantitative PCR Human epidermal keratinocytes were seeded on collagen-coated plates (Corning, #354500). After 24 hours, gyokuro extract (0.05% v / v%), perilla extract (0.05% v / v%), mallow extract (0.05% v / v%), and nettle extract (0.05% v / v%) were added to the culture medium, and the cells were cultured. 24 hours after drug addition, the stress hormone ((-)-Epinephrine (+)-bitartrate) (SIGMA) was added to the culture medium to a concentration of 10 μM. 24 hours after stress hormone addition, total RNA was extracted from the cells using RLT Reagent (QIAGEN), and reverse transcription was performed using the iScript Advanced cDNA Synthesis Kit for RT-qPCR (BioRad). The synthesized cDNA was used as a template, and quantitative PCR was performed using primers that amplified the ELOVL4 gene. The gene expression levels of each sample were standardized by the expression level of the housekeeping gene glyceraldehyde 3-phosphate dehydrogenase. Each sample was added to the culture medium to the concentrations shown in Tables 1 and 2. "Content in composition" refers to "content in the culture medium."

[0060] [Table 1]

[0061] [Table 2]

[0062] (2) Results The results are shown in Figures 1 and 2. As shown in Figures 1 and 2, it was confirmed that gyokuro extract, perilla extract, mallow extract, and nettle extract suppressed the decrease in ELOVL4 gene expression caused by the addition of stress hormones (adrenaline). These results confirm that tea extract, perilla extract, mallow extract, and nettle extract suppress the decrease in ELOVL4 gene expression caused by psychological stress and have the effect of improving skin barrier function. In addition, although apple extract and European beech bud extract are known to have a barrier function improving effect, it was found that they did not suppress the decrease in ELOVL4 gene expression caused by the addition of stress hormones.

[0063] <Prescription Examples 1-11> In formulation examples 1 to 11, cosmetics, quasi-drugs, and foods containing tea extract, perilla extract, mallow extract, or nettle extract were prepared.

[0064] [Prescription Example 1: Topical Solution] The topical solution was prepared using the following method. (Manufacturing method) A. The following components (1) to (7) were mixed and dissolved. B. The following components (8) to (11) were mixed and dissolved. CA was mixed with B to obtain the topical solution according to Formulation Example 1.

[0065] (1) Citric acid: 0.05% by mass (2) Sodium citrate: 0.2% by mass (3) Sodium pyrrolidone carboxylate (50%) solution: 0.5% by mass (4) Glycerin: 3.0% by mass (5) 1,3-Butylene glycol: 8.0% by mass (6) Tea extract: 0.5 mass (7) Purified water: remaining amount (8) Ethanol: 10.0% by mass (9) Fragrance: 0.1% by mass (10) Phenoxyethanol: 0.1% by mass (11) Polyoxyethylene (20E.O.) sorbitan monooleate: 0.5% by mass

[0066] [Prescription Example 2: Emulsion] The emulsion was prepared using the following method. (Manufacturing method) A. The following components (1) to (10) were heated and dissolved, and the temperature was maintained at 70°C. B. The following components (11) to (18) were heated and dissolved, and the temperature was maintained at 70°C. CA was emulsified with B, and then the following ingredient (19) was added and mixed. The DC was cooled, and the following component (20) was added and mixed to obtain the emulsion according to Formulation Example 2.

[0067] (1) Stearic acid: 1.0% by mass (2) Cetanol: 0.5% by mass (3) Lipophilic glyceryl monostearate: 0.5% by mass (4) Liquid paraffin: 2.0% by mass (5) Squalane: 3.0% by mass (6) Jojoba oil: 3.0% by mass (7) Cetyl palmitate: 0.2% by mass (8) Methyl parahydroxybenzoate: 0.1% by mass (9) Sorbitan monostearate: 0.3% by mass (10) Polyoxyethylene (20E.O.) sorbitan monooleate: 0.5% by mass (11) Triethanolamine: 0.5% by mass (12) 1,3-Butylene glycol: 15.0% by mass (13) Glycerin: 3.0% by mass (14) Polyethylene glycol 6000: 0.5% by mass (15) Tea extract: 0.1% by mass (16) Magnesium ascorbate phosphate: 0.5% by mass (17) Rice fermentation liquid: 1.0% by mass (18) Purified water: remaining amount (19) 1% carboxyl vinyl polymer solution: 8.0% by mass (20) Fragrance: 0.1% by mass

[0068] [Prescription Example 3: Ointment] The ointment was prepared using the following method. (Manufacturing method) A. The following components (1) to (13) were heated and dissolved, and the temperature was maintained at 70°C. B. The following components (14) to (19) were heated and dissolved, and the temperature was maintained at 70°C. CA was emulsified with B, and then the following ingredient (20) was added and mixed. The DC was cooled, and the following ingredient (21) was added and mixed to obtain the cream according to Formulation Example 3.

[0069] (1) Stearic acid: 2.5% by mass (2) Cetanol: 2.5% by mass (3) Lipophilic glyceryl monostearate: 2.0% by mass (4) Petrolatum: 2.0% by mass (5) Dipentaerythritol fatty acid ester: 2.0% by mass (6) Isotridecyl myristate: 5.0% by mass (7) Liquid paraffin: 8.0% by mass (8) Squalane: 5.0% by mass (9) Beeswax: 1.0% by mass (10) Cetyl palmitate: 2.0% by mass (11) Sorbitan sesquioleate: 0.5% by mass (12) Polyoxyethylene (20E.O.) sorbitan monooleate: 1.5% by mass (13) Phenoxyethanol: 0.2% by mass (14) Triethanolamine: 1.2% by mass (15) 1,3-Butylene glycol: 8.0% by mass (16) Glycerin: 2.0% by mass (17) Polyethylene glycol 20000: 0.5% by mass (18) Perilla extract: 1.0% by mass (19) Purified water: remaining amount (20) 1% carboxyl vinyl polymer solution: 10.0% by mass (21) Fragrance: 0.05% by mass

[0070] [Prescription Example 4: Serum] The serum was prepared using the following method. (Manufacturing method) A. The following components (1) to (8) were mixed and dissolved. B. The following components (9) to (18) were mixed and dissolved. A was added to CB and mixed to obtain the beauty serum according to Formulation Example 4.

[0071] (1) Glyceryl tri-2-ethylhexanoate: 0.1% by mass (2) Meadowhome oil: 0.05% by mass (3) Jojoba oil: 0.05% by mass (4) Methyl parahydroxybenzoate: 0.05% by mass (5) Fragrance: 0.05% by mass (6) Polyoxyethylene (20E.O.) sorbitan monooleate: 0.5% by mass (7) Polyoxyethylene hydrogenated castor oil isostearate (50 E.O.): 1.5% by mass (8) Ethanol: 5.0% by mass (9) Glycerin: 4.0% by mass (10) Dipropylene glycol: 8.0% by mass (11) 1,3-Butylene glycol: 8.0% by mass (12) Sodium lactate: 0.5% by mass (13) Sodium pyrrolidone carboxylate (50%) solution: 0.5% by mass (14) Perilla extract: 10.0% by mass (15) Arbutin: 0.2% by mass (16) Hydroxyethylcellulose: 0.08% by mass (17) Sodium alginate: 0.05% by mass (18) Purified water: remaining amount

[0072] [Prescription Example 5: Pack] The packs were prepared using the following method. (Manufacturing method) A. The following components (1) to (7) were heated and dissolved. B. The following components (8) to (12) were mixed and dissolved. After cooling CA, B was added and mixed to obtain the pack according to formulation example 5.

[0073] (1) Polyvinyl alcohol: 12.0% by mass (2) Methylcellulose: 0.1% by mass (3) Glycerin: 3.0% by mass (4) 1,3-Butylene glycol: 5.0% by mass (5) Mallow extract: 5.0% by mass (6) Clove extract: 0.5% by mass (7) Purified water: remaining amount (8) Fragrance: 0.02% by mass (9) Methyl parahydroxybenzoate: 0.05% by mass (10) Glyceryl tri-2-ethylhexanoate: 0.1% by mass (11) Polyoxyethylene (20E.O.) sorbitan monooleate: 1.0% by mass (12) Ethanol: 13.0% by mass

[0074] [Formulation Example 6: Liquid Foundation (O / W Type)] The liquid foundation was prepared using the following method. (Manufacturing method) A. The following components (1) to (7) were heated and dissolved. The following ingredients (8) to (11) were added to BA, mixed uniformly, and kept at 70°C. C. The following components (12) to (16) were heated and dissolved, and the temperature was maintained at 70°C. Add B to DC and emulsify. After cooling the ED, the following component (17) was added and mixed to obtain the liquid foundation (O / W type) according to Formulation Example 6.

[0075] (1) Stearic acid: 2.0% by mass (2) Cetanol: 0.5% by mass (3) Behenyl alcohol: 1.0% by mass (4) Vaseline: 2.5% by mass (5) Liquid paraffin: 5.0% by mass (6) Self-emulsifying glyceryl monostearate: 1.0% by mass (7) Methyl parahydroxybenzoate: 0.15% by mass (8) Titanium oxide: 6.0% by mass (9) Colored pigment: 4.0% by mass (10) Mica: 2.0% by mass (11) Talc: 4.0% by mass (12) Carboxymethylcellulose: 0.2% by mass (13) Bentonite: 0.4% by mass (14) Nettle extract: 0.01% by mass (15) 1,3-Butylene glycol: 8.0% by mass (16) Purified water: remaining amount (17) Fragrance: 0.2% by mass

[0076] [Formulation Example 7: Emulsion (O / W type)] The emulsion was prepared using the following method. (Manufacturing method) A: The following components (1) and (2) were uniformly dissolved and mixed at 70°C. B: The following components (3) to (11) were uniformly dissolved and mixed at 80°C. C: Add B to A and emulsify at 70°C. After adding and mixing the following components (12) to (17) in D:C, cool to 40°C. The following components (18) to (24), which were pre-mixed with E:D, were mixed to obtain an emulsion (O / W type).

[0077] (1) 1,3-Butylene glycol: 12.0% by mass (2) Purified water: remaining amount (3) Polyethylene glycol monostearate (40 E.O.): 0.5% by mass (4) Sorbitan sesquioleate: 0.1% by mass (5) Hydrogenated lecithin: 0.1 (6) Cholesteryl hydroxystearate: 3.0% by mass (7) Petrolatum: 2.0% by mass (8) α-olefin oligomer: 5.0% by mass (9) Shea butter: 2.0% by mass (10) Dimethylpolysiloxane (10CS): 1.0% by mass (11) Ceramide 3: 0.1% by mass (12) Cetostearyl alcohol: 2.0% by mass (13) Behenyl alcohol: 1.0% by mass (14) Methyl parahydroxybenzoate: 0.1% by mass (15) Acrylic acid / alkyl methacrylate copolymer: 0.1% by mass (16) Xanthan gum: 0.1% by mass (17) Sodium hydroxide: 0.03% by mass (18) Sodium hyaluronate: 0.0005% by mass (19) Polymethachloroyloxyethyl phosphorylcholine solution: 0.0025% by mass (20) Tea extract: 0.0001% by mass (21) Ethanol: 5% by mass (22) Astaxanthin: 0.1% by mass (23) Tocopherol: 0.01% by mass (24) Fragrance: 0.2% by mass

[0078] [Formulation Example 8: Beauty Serum (O / W type)] The serum was prepared using the following method. (Manufacturing method) A: The following components (1) to (3) were uniformly dissolved and mixed at 70°C. B: The following components (4) to (11) were uniformly dissolved and mixed at 80°C. C: Add B to A and emulsify at 70°C. After adding and mixing the following components (12) to (19) in D:C, cool to 40°C. The following pre-mixed ingredients (20) to (22) were added to E:D to obtain an oil-in-water emulsion beauty serum.

[0079] (1) 1,3-Butylene glycol: 5.0% by mass (2) Tripropylene glycol: 3.0% by mass (3) Purified water: remaining amount (4) Polyoxyethylene sorbitan monooleate (20 E.O.): 0.1% by mass (5) Polyethylene glycol monostearate (55 E.O.): 0.25% by mass (6) Macadamia nut oil fatty acid phytosteryl: 2.0% by mass (7) Light liquid isoparaffin: 3.0% by mass (8) Dimethylpolysiloxane (6CS): 3.0% by mass (9) Cholesterol: 0.1% by mass (10) Tocopherol: 0.01% by mass (11) Cetostearyl alcohol: 0.5% by mass (12) Methyl parahydroxybenzoate: 0.1% by mass (13) Carbomer: 0.15% by mass (14) (Sodium Acrylate / Sodium Acryloyldimethyl Taurate) Copolymer: 0.1% by mass (15) Sodium hydroxide: 0.05% by mass (17) Collagen: 0.1% by mass (18) Elastin: 0.1% by mass (19) Hyaluronic acid: 0.1% by mass (20) Ethanol: 5.0% by mass (21) Perilla extract: 0.005% by mass (22) Fragrance: 0.05% by mass

[0080] [Prescription Example 9: Ointment] The ointment was prepared using the following method. (Manufacturing method) A. The following components (5) to (11) were uniformly dissolved at 75°C. B. The following components (1) to (4) were uniformly dissolved at 75°C. B was gradually added to CA, emulsified at 75°C, and cooled to room temperature to obtain an ointment.

[0081] (1) Triethanolamine: 2.0% by mass (2) Glycerin: 8.0% by mass (3) Purified water: remaining amount (4) Sodium hyaluronate: 0.003% by mass (5) Mallow extract: 0.000005 mass (6) Polyquaternium-64: 0.004% by mass (7) Cetanol: 4.0% by mass (8) Vaseline: 30.0% by mass (9) Tocopherol: 0.01% by mass (10) Stearic acid: 18.0% by mass (11) Sorbitan sesquioleate: 1.5% by mass

[0082] [Prescription Example 10: Tablets] The tablets were prepared using the following method. (Manufacturing method) A. The following ingredients (1) to (7) were uniformly mixed, and tablets were obtained according to a conventional method.

[0083] (1) Lactose: 24.0% by mass (2) Crystalline cellulose: 20.0% by mass (3) Corn starch: 15.0% by mass (4) Nettle extract: 0.1% by mass (5) Glycerin fatty acid ester: 5.0% by mass (6) Silicon dioxide: 1.0% by mass (7) Dextrin: Remaining amount

[0084] [Prescription Example 11: Soft Drinks] The soft drink was prepared using the following method. (Manufacturing method) A. The following ingredients (1) to (5) were uniformly mixed, and a soft drink was obtained according to a conventional method.

[0085] (1) Fructose-glucose solution: 30.0% by mass (2) Emulsifier: 0.5% by mass (3) Tea tree extract: 0.01% by mass (4) Fragrance: 0.01% by mass (5) Purified water: remaining amount

Claims

1. A skin barrier function improving agent containing one or more extracts selected from the group consisting of tea extract, perilla extract, mallow extract, and nettle extract.

2. An ELOVL4 gene expression reduction inhibitor containing one or more extracts selected from the group consisting of tea extract, perilla extract, mallow extract, and nettle extract.

3. The ELOVL4 gene expression reduction inhibitor according to claim 2, wherein the reduction in ELOVL4 gene expression is caused by psychological stress.

4. The barrier function improving agent according to claim 1, or the ELOVL4 gene expression reduction inhibitor according to claim 2, wherein the tea extract is an extract of unfermented tea.

5. A composition containing the barrier function improving agent described in claim 1, or the ELOVL4 gene expression reduction inhibitor described in claim 2.

6. The composition according to claim 5, which is a cosmetic or a topical skin preparation.

7. A screening method for components that improve skin barrier function under psychological stress, using ELOVL4 gene expression levels as an indicator.

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