Pigmentation inhibitor, melanosome phagocytosis inhibitor, and epidermal differentiation agent

Abstract

To provide a new technique for inhibiting formation of pigmented spots.SOLUTION: The present invention provides a pigmented spot formation inhibitor including vitamin B6 as an active ingredient.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a pigment spot formation inhibitor, a melanosome phagocytosis enhancement inhibitor, and an epidermal differentiation ability improver.

Background Art

[0002] Pigment spots are formed by an increase in melanin due to a decrease in metabolism with aging or exposure of the skin to ultraviolet rays, and their formation is accelerated by enhanced melanosome phagocytosis of epidermal keratinocytes and a decrease in epidermal differentiation ability (for example, Non-Patent Document 1). Therefore, in order to suppress the formation of pigment spots, it is important to inhibit enhanced melanosome phagocytosis and improve epidermal differentiation ability.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, vitamin B6 compounds represented by pyridoxine are known to be effective in alleviating various symptoms such as angular cheilitis, cheilitis, glossitis, acute and chronic eczema, seborrheic eczema, contact dermatitis, etc. (for example, Non-Patent Document 2), but there is no report on whether they have an effect of inhibiting enhanced melanosome phagocytosis, an effect of improving epidermal differentiation ability, or an effect of inhibiting pigment spot formation.

[0005] An object of the present invention is to provide a new technique for suppressing the formation of pigment spots.

Means for Solving the Problems

[0006] The problem to be solved by the present invention is as follows: <1> ~ <13> The problem was solved by the following means. <1> A pigment spot formation inhibitor containing vitamin B6 as an active ingredient (hereinafter also referred to as the pigment spot formation inhibitor of the present invention). <2> A melanosome phagocytosis-enhancing inhibitor containing vitamin B6 as an active ingredient (hereinafter also referred to as the melanosome phagocytosis-enhancing inhibitor of the present invention). <3> An epidermal differentiation ability improving agent containing vitamin B6 as an active ingredient (hereinafter also referred to as the epidermal differentiation ability improving agent of the present invention). <4> The aforementioned vitamin B6 is one or more selected from pyridoxine, pyridoxal, pyridoxamine, and their salts. <1> ~ <3> The agent described in any of the following.

[0007] <5> Use of vitamin B6 derivatives for the manufacture of pigment spot formation inhibitors. <6> Use of vitamin B6 derivatives to suppress the formation of pigment spots. <7> A method for inhibiting the formation of pigment spots, which includes a step using vitamin B6. <8> Use of vitamin B6 derivatives for the manufacture of melanosome phagocytosis inhibitors. <9> Use of vitamin B6 derivatives to suppress the increased phagocytosis of melanosomes. <10> A method for inhibiting enhanced melanosome phagocytosis, which includes a step using vitamin B6. <11> Use of vitamin B6 derivatives for the manufacture of epidermal differentiation ability improving agents. <12> Use of vitamin B6 derivatives to improve epidermal differentiation ability. <13> A method for improving epidermal differentiation ability, including a step using vitamin B6. [Effects of the Invention]

[0008] The melanosome phagocytosis enhancement inhibitor of the present invention has an excellent melanosome phagocytosis enhancement inhibitory effect. The epidermal differentiation ability improving agent of the present invention has an excellent effect in improving epidermal differentiation ability. Therefore, according to the present invention, a pigment spot formation inhibitor with excellent pigment spot formation inhibitory effect can be provided. [Brief explanation of the drawing]

[0009] [Figure 1] A diagram showing the inhibitory effect of pyridoxine on melanosome phagocytosis (under UVB irradiation). [Figure 2] A diagram showing the inhibitory effect of pyridoxine on melanosome phagocytosis (BSO treatment). [Figure 3] A diagram showing the effect of pyridoxine on improving epidermal differentiation ability. [Modes for carrying out the invention]

[0010] The pigment spot formation inhibitor, the melanosome phagocytosis enhancement inhibitor, and the epidermal differentiation ability improving agent of the present invention all contain vitamin B6 as an active ingredient.

[0011] Examples of vitamin B6 include one or more selected from pyridoxine, pyridoxal, and pyridoxamine, as well as their salts (e.g., alkaline earth metal salts such as calcium salts; inorganic salts such as hydrochloride and phosphate). Among these, one or more selected from pyridoxine and its salts are preferred from the viewpoint of inhibiting melanosome phagocytosis, improving epidermal differentiation ability, and inhibiting pigment spot formation, and one or more selected from pyridoxine and pyridoxine hydrochloride are more preferred. Vitamin B6 compounds may be either commercially available or synthesized using known methods.

[0012] Furthermore, as shown in the examples below, vitamin B6 compounds exhibit excellent effects in inhibiting melanosome phagocytosis and improving epidermal differentiation. Therefore, vitamin B6 compounds can suppress the increased phagocytosis of melanosomes in epidermal keratinocytes, improve epidermal differentiation, and are useful as inhibitors of pigmented lesion formation. Furthermore, vitamin B6 compounds can act as inhibitors of increased melanosome phagocytosis, improve epidermal differentiation, and inhibit pigmented lesion formation, and can be used for suppressing increased melanosome phagocytosis, improving epidermal differentiation, and inhibiting pigmented lesion formation. They can also be used to manufacture inhibitors of increased melanosome phagocytosis, improve epidermal differentiation, and inhibit pigmented lesion formation. In addition, the melanophagocytosis hyperactivity inhibitor, the epidermal differentiation ability improver, and the pigmented spot formation inhibitor can be used as pharmaceuticals, quasi-drugs, cosmetics, or foods effective for suppressing melanophagocytosis hyperactivity, improving epidermal differentiation ability, and suppressing pigmented spot formation, or as materials to be incorporated into pharmaceuticals, quasi-drugs, cosmetics, or foods. Here, "suppressing melanophagocytosis hyperactivity" means suppressing the hyperactivity of melanophagocytosis in epidermal keratinocytes, and "improving epidermal differentiation ability" means improving the decline in epidermal differentiation ability (particularly the decline in epidermal differentiation ability due to melanophagocytosis hyperactivity). Also, "suppressing pigmented spot formation" means suppressing the formation of skin pigmented spots (particularly skin pigmented spot formation due to melanophagocytosis hyperactivity and / or decline in epidermal differentiation ability).

[0013] In addition, the above "use" can be administration or ingestion to humans or non-human animals, and can be either therapeutic use or non-therapeutic use. Note that "non-therapeutic" is a concept that does not include medical acts, that is, a concept that does not include methods of operating on, treating, or diagnosing humans, and more specifically, a concept that does not include methods of a doctor or a person receiving a doctor's instruction performing surgery, treatment, or diagnosis on a human.

[0014] Note that foods can be health functional foods that take suppressing melanophagocytosis hyperactivity, improving epidermal differentiation ability, and suppressing pigmented spot formation as concepts and display the same, such as foods with functional claims, foods for specified health uses, nutritional functional foods, etc. Specific forms include tablets, capsule agents (soft capsules and hard capsules), granules, drink agents, confectionery (jelly, gummy, chocolate, etc.) for the purpose of suppressing melanophagocytosis hyperactivity, improving epidermal differentiation ability, suppressing pigmented spot formation, etc., and it is also possible to use them as materials to be added to supplements and foods in liquid or powder form.

[0015] The application means of the melanophagocytosis hyperactivity inhibitor, the epidermal differentiation ability improver, and the pigmented spot formation inhibitor of the present invention can be any of oral administration, injection, external application to the skin, etc., but oral administration or external application to the skin is preferred. Note that "skin" is a concept that includes the skin of the face, body, hands and feet, and scalp. When the melanosome phagocytosis enhancement inhibitor, epidermal differentiation ability improving agent, and pigment spot formation inhibitor of the present invention are administered orally, the dosage forms may include solid preparations such as tablets, granules, and capsules; semi-solid preparations; and liquid preparations. These dosage forms may be used for pharmaceuticals, quasi-drugs, or foods. Furthermore, when used as an oral administration composition, in addition to the above-mentioned active ingredients, additives such as excipients, disintegrants, binders, and lubricants may be included. When the melanosome phagocytosis enhancement inhibitor, epidermal differentiation ability improving agent, and pigment spot formation inhibitor of the present invention are used as topical skin preparations, the dosage forms include ointments, creams, emulsions, gels, pastes, lotions, etc. In these topical skin preparations, in addition to the above-mentioned active ingredients, various components commonly used as bases or additives in topical preparations may be included. For example, solid, semi-solid, or liquid oils such as natural animal and vegetable oils and fats, semi-synthetic oils and fats, hydrocarbon oils, higher fatty acids, higher alcohols, ester oils, silicone oils, and fluorinated oils; water; alcohols such as lower alcohols, sugar alcohols, and sterols; plant-derived polymers such as gum arabic and tragacanth; microbial polymers such as xanthan gum and dextran; starch-derived polymers such as carboxymethyl starch; cellulose-derived polymers such as sodium carboxymethylcellulose; surfactants such as various anionic, cationic, nonionic, and amphoteric surfactants; oil-soluble gelling agents such as metal soaps, dextrin fatty acid esters, and sucrose fatty acid esters; inorganic powders such as titanium dioxide, magnesium carbonate, mica, and hydroxyapatite; organic powders such as polyamide powder; colored pigments; pearl pigments; humectants; preservatives; pH adjusters; chelating agents; cooling agents; anti-inflammatory agents; and skin-beautifying ingredients such as whitening agents, cell activators, and blood circulation promoters.

[0016] In the melanosome phagocytosis enhancement inhibitor, epidermal differentiation ability improving agent, and pigment spot formation inhibitor of the present invention, the vitamin B6 content is preferably 0.001 to 90% by mass, more preferably 0.01 to 20% by mass, and even more preferably 0.1 to 10% by mass. The melanosome phagocytosis enhancement inhibitor, epidermal differentiation ability improving agent, and pigment spot formation inhibitor of the present invention are administered by ingestion or topical application in the form of vitamin B6, preferably 0.1 to 100 mg, more preferably 1 to 50 mg, and even more preferably 5 to 50 mg per day to adults. [Examples]

[0017] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0018] [Test Example 1: Enhanced phagocytosis of fluorescent beads by UVB irradiation and the inhibitory effect of VB6 on enhanced phagocytosis] Add 0.1 mL / well of culture medium (HuMedia-KG2: manufactured by Kurabo Industries Ltd.) to a 96-well plate, and add 2.5 × 10⁶ Normal Human Epidermal Keratinocytes (NHEK). 4 After seeding at a density of cells / well, the cells were incubated for 24 hours. These were then divided into four groups. For group 1 (Vitamin B6 + UVB group), the medium was changed to pyridoxine-containing medium (pyridoxine 1 mM) and incubated for 24 hours, with UVB exposure at 20 mJ / cm² using a Philips UVB broadband lamp. 2 After irradiation, the cells were cultured for 24 hours. For the second group (vitamin B6 group), the culture medium was changed to a pyridoxine-containing medium (pyridoxine 1 mM) and cultured for 24 hours. For the third group (UVB group), UVB was applied at 20 mJ / cm using a Philips UVB broadband lamp. 2 After irradiation, the cells were cultured for 24 hours, while the fourth group (untreated, unirradiated group) was cultured for 48 hours. Subsequently, fluorescent beads (Thermo Fisher Scientific) were incorporated into each group of NHEK proteins as pseudo-melanosomes for 4 hours, and the amount of fluorescent beads incorporated per unit protein was measured using a microplate reader (Tecan). The results are shown in Figure 1.

[0019] [Test Example 2: Enhanced phagocytosis of fluorescent beads by BSO treatment and inhibitory effect of VB6 on enhanced phagocytosis] Add 0.1 mL / well of culture medium (HuMedia-KG2) to a 96-well plate and add 2.5 × 10⁶ Normal Human Epidermal Keratinocytes (NHEK). 4 After seeding at a density of cells / well, the cells were incubated for 24 hours. These were then divided into four groups: Group 1 (Vitamin B6 + BSO group) was treated with 50 μM butionine sulfoximine (BSO: Sigma-Aldrich) for 24 hours, then cultured for 24 hours in pyridoxine-containing medium (pyridoxine 0.25 mM, 0.5 mM, or 1 mM). Group 2 (Vitamin B6 group) was cultured for 24 hours in pyridoxine-containing medium (pyridoxine 0.25 mM, 0.5 mM, or 1 mM). Group 3 (BSO group) was treated with 50 μM butionine sulfoximine (BSO) for 24 hours, then cultured for 24 hours in KG2 medium. Group 4 (no additive group) was cultured for 48 hours as is. Subsequently, fluorescent beads (Thermo Fisher Scientific) were incorporated into each group of NHEK for 4 hours, and the amount of fluorescent beads incorporated per unit protein was measured using a microplate reader (Tecan). The results are shown in Figure 2.

[0020] [Test Example 3: Effect of improving decreased epidermal differentiation ability caused by phagocytosis of fluorescent beads] Add 0.1 mL / well of culture medium (HuMedia-KG2) to a 96-well plate and add 2.5 × 10⁶ Normal Human Epidermal Keratinocytes (NHEK). 4After seeding at a density of cells / well, the cells were incubated for 24 hours. These were divided into three groups: Group 1 (Vitamin B6 + Beads group) was cultured for 24 hours in pyridoxine-containing medium (pyridoxine 1 mM), then incorporated fluorescent beads (Thermo Fisher Scientific) as pseudo-melanosomes for 4 hours, and then cultured for another 20 hours in fresh medium (HuMedia-KG2). Group 2 (Beads group) was cultured for 24 hours, then incorporated fluorescent beads (Thermo Fisher Scientific) as pseudo-melanosomes for 4 hours, and then cultured for another 20 hours in fresh medium (HuMedia-KG2). Group 3 (Control group) was cultured for 48 hours as usual. Subsequently, total RNA was extracted from NHEK cells in each group, and cDNA was constructed by reverse transcription. Real-time PCR was performed using this cDNA as a template to detect the gene expression levels of keratin-10, involucrin, and loricrin. The results are shown in Figure 3.

Claims

[Claim 1] A melanosome phagocytosis-enhancing inhibitor for suppressing the formation of pigment spots due to age-related metabolic decline, comprising vitamin B6 compounds, wherein the vitamin B6 compounds are one or more selected from pyridoxine and its salts.

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