Method for suppressing adhesion of air pollutants

Abstract

To provide an anti-pollution agent that reduces skin damage caused by air pollutants.SOLUTION: An anti-pollution agent contains hydrolyzed sericin as an active ingredient. The hydrolyzed sericin preferably has an average weight molecular weight of 3,000-50,000. A method for suppressing attachment of air pollutants includes applying, spraying or sticking an anti-pollution agent containing hydrolyzed sericin as an active ingredient to the skin of a subject, thereby suppressing the attachment of air pollutants to the skin.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an anti-pollution agent. [Background technology]

[0002] The skin is constantly exposed to external stimuli such as ultraviolet rays and air pollutants. Ultraviolet rays have long been studied as a factor that affects the skin, and many materials are known that mitigate damage caused by ultraviolet rays.

[0003] Air pollutants are said to damage cells by adhering to and penetrating the skin. Perhaps because air pollutants are a mixture of various chemical substances, the mechanisms of cell damage are extremely diverse, including oxidation, inflammation, and abnormalities in cell metabolism and gene expression. In recent years, research into the effects of air pollutants on the skin has progressed, and ingredients that protect the skin from air pollutants have been discovered.

[0004] For example, Patent Document 1 discloses a pollution prevention agent characterized by containing mannosylerythritol lipid (MEL), and Patent Document 2 discloses an anti-pollution agent containing hyaluronic acid and / or a salt thereof as an active ingredient.

[0005] As described above, methods proposed for protecting the skin from air pollutants include preventing substances that may cause damage from coming into contact with the skin and / or mitigating the effects of substances that do come into contact with the skin (by preventing oxidation or neutralizing them).

[0006] Sericin, a silk protein, contains many hydrophilic amino acids and has excellent biocompatibility, and its application in foods, cosmetics, medicines, etc. has been considered, and some applications have been put to practical use. For example, Patent Document 3 discloses an antioxidant containing sericin as an active ingredient, Patent Document 4 discloses cell protection after ultraviolet irradiation, erythema suppression, pigmentation suppression, wrinkle formation suppression, and treatment of skin disorders, Patent Document 5 discloses a filaggrin production promoter containing sericin as an active ingredient, and Patent Document 6 discloses a surfactant made of sericin. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] WO2019 / 167458 issue [Patent Document 2] JP 2017-186276 A [Patent Document 3] Japanese Patent Application Publication No. 10-140154 [Patent Document 4] JP 2003-252744 A [Patent Document 5] JP 2014-159389 A [Patent Document 6] JP 2008-221209 A Summary of the Invention [Problem to be solved by the invention]

[0008] The pollution prevention agent of Patent Document 1 is effective in preventing air pollutants from adhering to the skin, but is ineffective in mitigating skin damage (cell damage) caused by adhering air pollutants. The anti-pollution agent of Patent Document 2 is effective in mitigating skin damage caused by air pollutants by preventing the adhesion and penetration of air pollutants, but the effect is not sufficient. Patent Documents 3 to 6 do not mention or suggest the effect of sericin in protecting the skin from air pollutants.

[0009] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an anti-pollution agent that alleviates damage to the skin caused by air pollutants. [Means for solving the problem]

[0010] The present inventors have discovered that hydrolyzed sericin has the effect of inhibiting adhesion of air pollutants to the skin and the effect of alleviating damage to the skin caused by air pollutants, and have completed the present invention.

[0011] According to an embodiment of the present invention Method for suppressing adhesion of air pollutants teeth, A method for suppressing adhesion of air pollutants to the skin by applying, spraying or attaching an anti-pollution agent containing hydrolyzed sericin as an active ingredient to the skin. It is. Effect of the Invention

[0012] According to an embodiment of the present invention, an anti-pollution agent that alleviates damage to the skin caused by air pollutants can be provided. [Brief description of the drawings]

[0013] [Figure 1] 1 is an image showing the adhesion prevention effect of Example 1. [Diagram 2] 1 is an image showing the adhesion prevention effect of Example 3. [Diagram 3] 1 is an image showing the adhesion prevention effect of Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An anti-pollution agent according to an embodiment of the present invention contains hydrolyzed sericin as an active ingredient.

[0015] In the present invention, anti-pollution refers to the effect of alleviating skin damage caused by air pollutants. More specifically, it includes not only suppressing adhesion of air pollutants to the skin, but also alleviating skin damage by comprehensively suppressing metabolic disorders, inflammation, oxidation, etc. of cells caused by adhesion and penetration of air pollutants into the skin.

[0016] In the present invention, air pollutants refer to substances that have adverse effects on the skin. For example, they include, but are not limited to, chemical substances and foreign substances such as smoke from automobiles, thermal power plants, incinerators, fireplaces, cigarettes, etc., particulate matter from volcanic eruptions, soil particles, etc., carbon monoxide, sulfur oxides (sulfur dioxide, etc.), nitrogen oxides (nitrogen dioxide, etc.) and other exhaust gases from pollen, dust, combustion, etc., photochemical oxidants such as ozone (O3) and polycyclic aromatic hydrocarbons (PAHs) that are generated by photochemical reactions between hydrocarbons and nitrogen oxides, exhaust gases and fine particles such as volatile organic compounds (VOCs) (aldehydes such as formaldehyde, PAHs, dioxins, etc.) that are generated from combustion and petroleum products, and fine particles such as asbestos that are generated from minerals and industrial products.

[0017] The hydrolyzed sericin used in the present invention is easily available as a hydrolyzate from silkworm cocoons, raw silk, etc. That is, the hydrolyzed sericin used in the present invention can be obtained by partially hydrolyzing and eluting sericin from raw materials such as silkworm cocoons and raw silk by, for example, hydrolysis with high-temperature high-pressure water, acid hydrolysis using hydrochloric acid, sulfuric acid, phosphoric acid, etc., alkali hydrolysis using sodium hydroxide, sodium carbonate, etc., or enzymatic hydrolysis using proteases derived from microorganisms or plants. A high-purity aqueous solution of sericin hydrolyzate can be obtained by purifying the resulting solution according to a known protein separation and purification method. Furthermore, the hydrolyzed sericin may be dried by treatment such as hot air drying, reduced pressure drying, or freeze drying to obtain a solid.

[0018] The hydrolyzed sericin preferably contains 20-40 mol% serine as an amino acid composition. When the serine content is 20 mol% or more, the various actions and effects of sericin, particularly water retention, can be fully obtained. The hydrolyzed sericin preferably contains 55-75 mol% hydrophilic amino acids. When the hydrophilic amino acid content is 55-75 mol%, it absorbs moisture in the air and forms a conductive antistatic film on the skin surface, thereby suppressing adhesion of air pollutants to the skin. The amino acid composition can be measured and determined by a post-column derivatization-fluorescence detection method using a high-performance liquid chromatograph amino acid analysis system LC-10 (manufactured by Shimadzu Corporation).

[0019] The weight-average molecular weight of hydrolyzed sericin is usually distributed in the range of 1,000 to 150,000, and any of them can be used in the present invention. According to a preferred embodiment of the present invention, the weight-average molecular weight of hydrolyzed sericin is preferably 3,000 to 50,000, more preferably 10,000 to 30,000. A weight-average molecular weight of 3,000 or more is considered to be advantageous in terms of exerting physiological activities such as antioxidant properties and protecting the skin from air pollutants. In addition, a weight-average molecular weight of 10,000 or more is considered to be advantageous in terms of easily forming a polymer film on the skin and suppressing adhesion of air pollutants to the skin. In addition, a weight-average molecular weight of 50,000 or less is considered to be advantageous in terms of preventing deterioration in handleability due to a decrease in water solubility of the hydrolyzed sericin itself and precipitation of the hydrolyzed sericin over time, thereby maintaining the stability of the anti-pollution agent. The weight average molecular weight can be determined by GPC analysis using a high performance liquid chromatograph CLASS-LC10 (manufactured by Shimadzu Corporation).

[0020] The hydrolyzed sericin used in the present invention has an amino acid composition similar to that of natural moisturizing factors, and contains a high proportion of amino acids having hydroxyl groups and amino acids having carboxyl groups. As a result, it is highly hydrophilic, has strong adhesion to the skin, and is expected to be highly effective in improving the skin environment (moisture content) of the stratum corneum.

[0021] According to the study by the present inventors, it was found that hydrolyzed sericin has an effect of suppressing damage to skin epidermal cells caused by air pollutants, and has an antistatic effect (see Evaluation Tests 2 and 3). The hydrolyzed sericin used in the present invention has high water retention and amphiphilic action, and is therefore considered to form a conductive antistatic film on the skin surface, thereby exerting an antistatic effect. In addition, the hydrolyzed sericin of the present invention forms a polymer film (coating), which is considered to physically inhibit adhesion of air pollutants to the skin. If an effect of suppressing adhesion of air pollutants can be obtained, it is considered to be advantageous in mitigating damage to the skin. Note that the explanation of these action mechanisms is one theoretical consideration, and does not limit the present invention.

[0022] More specifically, hydrolyzed sericin has an excellent effect of preventing adhesion of air pollutants due to the above-mentioned antistatic effect and physical inhibition, and therefore can alleviate skin damage caused by air pollutants. In addition, hydrolyzed sericin itself can alleviate skin damage by comprehensively suppressing metabolic disorders, inflammation, oxidation, etc. of cells caused by air pollutants. Furthermore, hydrolyzed sericin itself has an anti-inflammatory effect and a barrier function improving effect, so it is expected to suppress and improve inflammation and rough skin caused by air pollutants.

[0023] The anti-pollution agent according to the present embodiment refers to hydrolyzed sericin itself or a composition obtained by dispersing or dissolving hydrolyzed sericin in a solvent. The solvent is not particularly limited as long as it can disperse or dissolve hydrolyzed sericin, and any water-soluble base can be used. Examples of water-soluble bases include water, ethanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-butylene glycol, 1,3-propanediol, pentylene glycol, and glycerin. These water-soluble bases may be used alone or in combination.

[0024] In the anti-pollution agent of the present invention, the content of hydrolyzed sericin is not particularly limited, and can be appropriately adjusted depending on the formulation of the anti-pollution agent and the composition ratio of other ingredients.

[0025] For example, when the anti-pollution agent is a composition in which hydrolyzed sericin is dispersed or dissolved in a solvent, the content is preferably 0.001 to 20% by mass, more preferably 0.01 to 10% by mass, based on the total amount of the anti-pollution agent. By having a content of 0.001% by mass or more, a sufficient polymer film of hydrolyzed sericin is formed on the skin surface, and the antistatic effect of hydrolyzed sericin is considered to be advantageous in suppressing adhesion of air pollutants to the skin and protecting the skin from air pollutants. In addition, the moisturizing effect is sufficiently exerted, so that the effect of improving the barrier function of the skin is excellent. By having a content of 20% by mass or less, the anti-pollution agent has excellent stability over time and is easy to handle when compounding the anti-pollution agent.

[0026] The anti-pollution agent according to the present invention can be appropriately blended with moisturizers, UV absorbers, emulsifiers, thickeners, surfactants, chelating agents, oily components, alcohols, coloring materials, powdered components, vitamins, anti-inflammatory agents, pH adjusters, preservatives, extracts derived from animals, plants, fish and shellfish, or microorganisms, fragrances, etc., as necessary, within the scope that does not impair the effects of the present invention.

[0027] The dosage form of the anti-pollution agent of the present invention is not particularly limited as long as it does not impair the effects of the present invention, and may be any dosage form that can be applied, sprayed, or stuck to the skin, hair, etc. For example, lotion, beauty essence, milky lotion, cream, gel, pack, spray, roll-on, stick, soap, sheet, mousse, ointment, foundation, lip cream, bath additive, hair tonic, hair lotion, soap, facial cleanser, body shampoo, etc. can be appropriately selected.

[0028] By adding the various components as described above to the anti-pollution agent of the present invention, it is expected that the agent will provide effects such as moisturizing effect, cell activation effect, anti-aging effect, and skin roughness improving effect, depending on the components.

[0029] The anti-pollution agent of the present invention can be used by applying, spraying or attaching it to an object on which it is desired to prevent adhesion of air pollutants, such as hair and skin.

[0030] The anti-pollution agent of the present invention can be used daily, and the active ingredient hydrolyzed sericin acts to suppress adhesion of air pollutants to the skin and alleviate skin damage caused by the attached air pollutants. Therefore, the anti-pollution agent of the present invention can suppress the occurrence of skin damage caused by air pollutants and alleviate skin damage, and the anti-inflammatory effect of the hydrolyzed sericin itself is expected to suppress inflammation caused by air pollutants. Therefore, it can be suitably used as a skin external preparation used to protect the skin from the external environment. Furthermore, in addition to the effect of preventing adhesion of air pollutants and the anti-inflammatory effect, hydrolyzed sericin has an effect of improving barrier function, so that it is expected to show useful effects on the skin through different mechanisms, and by using it as a skin external preparation, it is expected that various skin symptoms, such as dry skin, rough skin, atopic dermatitis, and psoriasis, caused by inflammation caused by air pollutants, can be effectively prevented and improved. In addition, the anti-pollution agent of the present invention contains hydrolyzed sericin as an active ingredient, and is advantageous in terms of excellent safety. EXAMPLES

[0031] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. The blend amounts are expressed in mass % unless otherwise specified.

[0032] <Materials used in the examples> In this example, hydrolyzed sericin prepared by the following method was used.

[0033] [Preparation of hydrolyzed sericin (I) powder (weight average molecular weight 4,000)] Silkworm cocoons from which pupae had been removed were treated with 1.0% by mass sodium carbonate aqueous solution (pH 11-12) at 95°C for 2 hours to extract hydrolyzed sericin. The resulting extract was filtered through a filter with an average pore size of 0.2 μm to remove aggregates, and the filtrate was desalted using a dialysis membrane to obtain a sericin hydrolyzate extract with a concentration of 0.9% by mass. This extract was freeze-dried to obtain hydrolyzed sericin powder. The molecular weight distribution of this hydrolyzed sericin was 1,000-40,000, the weight average molecular weight was 4,000, and the amino acid composition contained 27 mol% serine and 61 mol% hydrophilic amino acids.

[0034] [Preparation of hydrolyzed sericin (II) powder (weight average molecular weight 8,000)] A powder of hydrolyzed sericin (II) having a molecular weight distribution of 1,000 to 80,000, a weight average molecular weight of 8,000, a serine content of 26 mol%, and a hydrophilic amino acid content of 61 mol% was obtained in the same manner as in the preparation of powder of hydrolyzed sericin (I), except that 0.5 mass% sodium carbonate (pH 11-12) was used instead of 1.0 mass% sodium carbonate (pH 11-12).

[0035] [Preparation of hydrolyzed sericin (III) powder (weight average molecular weight 13,000)] A powder of hydrolyzed sericin (III) having a molecular weight distribution of 2,000 to 120,000, a weight average molecular weight of 13,000, a serine content of 31 mol%, and a hydrophilic amino acid content of 71 mol% was obtained in the same manner as in the preparation of powder of hydrolyzed sericin (I), except that 0.3 mass% sodium carbonate (pH 11-12) was used instead of 1.0 mass% sodium carbonate (pH 11-12).

[0036] [Preparation of hydrolyzed sericin (IV) powder (weight average molecular weight 25,000)] A powder of hydrolyzed sericin (IV) was obtained in the same manner as in the preparation of powder of hydrolyzed sericin (I), except that 0.15% by mass sodium carbonate (pH 11-12) was used instead of 1.0% by mass sodium carbonate (pH 11-12). The powder had a molecular weight distribution of 3,000-200,000, a weight average molecular weight of 25,000, a serine content of 32 mol%, and a hydrophilic amino acid content of 71 mol%.

[0037] [others] Betaine: Aminocoat (registered trademark) (manufactured by Asahi Kasei Finechem Corporation)

[0038] [Evaluation test 1 (Effect of hydrolyzed sericin on inhibiting adhesion of pollutants)] The hydrolyzed sericins (I)-(IV) were evaluated for their ability to inhibit adhesion of pollutants to human skin. The inner arm of a healthy subject was used as the test site. The test site was washed with soap and conditioned at room temperature of 25°C and relative humidity of 50% for 20 minutes. A Kimwipe (cut to 2cm x 2cm and used, manufactured by Nippon Paper Crecia Co., Ltd.) impregnated with 150μL of the anti-pollution agent of Example 1 was placed on the test site and left to stand for 10 minutes. The Kimwipe was removed and the test site was allowed to dry naturally. 0.01g of carbon black was applied to the dried test site. After exposing the test site to carbon black for 5 minutes, it was washed with running water in a shower for 10 seconds and the moisture on the surface was removed without rubbing. The adhesion of the carbon black was evaluated visually and with a microscope (for example, USB microscope M3 (manufactured by Scalar Co., Ltd.)). The test site of Comparative Example 1 was used as a control and evaluated based on the following evaluation criteria. Examples 2 to 6 and Comparative Examples 1 to 3 were also evaluated in the same manner. [Evaluation Criteria] ◎: Significantly less adhesion than the control ○: Adhesion is slightly less than the control △: Same adhesion as the control ×: More adhesion than the control

[0039] [Evaluation test 2 (antistatic effect of hydrolyzed sericin)] The antistatic effects of hydrolyzed sericins (III) and (IV) were evaluated. Nylon fabric (knitted, 78 courses / 25.4 mm, 80 wel / 25.4 mm, weight 0.025 g / cm 2 A cloth (7 cm x 3 cm) was impregnated with 2.5 mL of the anti-pollution agent of Example 3 and then dried at 35°C for 24 hours to completely evaporate the water. The dried test cloth was conditioned for 2 hours in an incubator at 40°C and a relative humidity of 75%, simulating the temperature and humidity on the surface of human skin, to prepare a test cloth. The test cloth was a friction cloth (polyester cloth, knitted, 100 courses / 25.4 mm, 66 wells / 25.4 mm, basis weight 0.02 g / cm 2 The test cloth was rubbed 50 times with a cloth measuring 1.5 mm x 1.7 cm x 3 cm, and the electrostatic potential of the test cloth surface was measured with a digital electrostatic potential meter (KSD-0103, manufactured by Kasuga Electric Co., Ltd.). Three test cloths and three friction cloths were prepared, and the average of the measured values ​​was taken as the electrostatic potential. Examples 4 to 6 and Comparative Examples 1 to 3 were also evaluated in the same manner.

[0040] [Table 1]

[0041] The contaminant adhesion prevention effect and antistatic effect of each sample are shown in Table 1. From Table 1, the antistatic effect was confirmed in the antipollution agents of Examples 3 to 6 containing hydrolyzed sericin. Moreover, the effect was almost the same as that of betaine, which is known to have an antistatic effect (Comparative Examples 2 and 3). Moreover, the anti-pollution agents of Examples 1 to 6, which contain hydrolyzed sericin, were found to have an effect of inhibiting adhesion of pollutants. Some of the evaluation results are shown in the figures. FIG. 1 is a photograph showing the adhesion prevention effect of Example 1, FIG. 2 is a photograph showing the adhesion prevention effect of Example 3, and FIG. 3 is a photograph showing the adhesion prevention effect of Comparative Example 1. Example 1 had a slightly lower adhesion amount than the control (Comparative Example 1) (FIGS. 1 and 3), and Example 3 had a significantly lower adhesion amount than the control (Comparative Example 1) (FIGS. 2 and 3). In Table 1, the examples marked with "◎" in the column for adhesion prevention effect had an adhesion amount similar to that of Example 3, the examples marked with "◯" had an adhesion amount similar to that of Example 1, and the comparative examples marked with "△" had an adhesion amount similar to that of Comparative Example 1. An excellent adhesion inhibitory effect was observed in Examples 3 and 4, which contained hydrolyzed sericin (III) and (IV) (weight-average molecular weights of 13,000 and 25,000, respectively). Moreover, an excellent adhesion inhibitory effect was observed as the content of hydrolyzed sericin increased (Examples 3, 5, and 6). The effect was superior to that of betaine (Comparative Examples 2 and 3), which is known to have an antistatic effect. This is believed to be because, in addition to the antistatic effect of hydrolyzed sericin, the hydrolyzed sericin formed a polymer film on the skin, physically inhibiting the adhesion of carbon black to the skin.

[0042] [Evaluation test 3 (Effect of hydrolyzed sericin on alleviating damage to skin epidermal cells)] The effect of hydrolyzed sericin (IV) on alleviating damage to skin epidermal cells was evaluated. The test used air pollution model substances (environmental standard sample NIES CRM No. 28, urban air dust Urban Aerosols (UA), National Institute for Environmental Studies) and a 3D skin culture model (LabCyte EPI-MODEL 6D, Japan Tissue Engineering Co., Ltd.). The above-mentioned hydrolyzed sericin (IV) was dissolved in purified water to a concentration of 2 mass % to prepare an anti-pollution agent of Example 7. In addition, purified water in which hydrolyzed sericin was not dissolved was prepared as Comparative Example 1. First, the 3D skin culture model was pre-cultured in an incubator for 24 hours. 25 μL each of the anti-pollution agent of Example 7 and UA was added to the epithelial side of the 3D skin culture model and cultured for 48 hours. The concentration of UA was 12.5% ​​by mass. 15 minutes, 1 hour, 3 hours, 8 hours, and 24 hours after adding the anti-pollution agent of Example 7 and UA, the epithelial side of the 3D skin culture model was washed 15 times with phosphate buffered saline (PBS). The number of cells after culture was measured using an intracellular metabolic activity measurement kit (Cell Counting Kit-8, Dojindo Laboratories). That is, after culturing the 3D skin culture model in a medium containing 10% Cell Counting Kit-8 reagent for 2 hours, the absorbance at wavelengths of 450 nm and 620 nm was measured, and the difference was taken as the measured value. For example, a Multiskan FC absorbance microplate reader (manufactured by Thermo Fisher Scientific Co., Ltd.) can be used to measure the absorbance. The cell viability of each sample was calculated based on the measured value 15 minutes after the addition of the anti-pollution agent and UA, which had no effect on the 3D skin culture model, as 100%, and the viability was calculated 1 hour, 3 hours, 8 hours, and 24 hours after the addition. Comparative Example 1 was also evaluated in the same manner.

[0043] The cell viability of each sample is shown in Table 2. As can be seen from Table 2, the addition of UA reduced the cell viability, but the anti-pollution agent of Example 7 containing hydrolyzed sericin mitigated the reduction in cell viability caused by UA. In other words, the effect of mitigating damage to skin epidermal cells by hydrolyzed sericin was confirmed.

[0044] [Table 2]

Claims

[Claim 1] A method for inhibiting adhesion of air pollutants to the skin by applying, spraying or sticking an anti-pollution agent containing hydrolyzed sericin as an active ingredient to the skin.

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