JP6374579B2 - Skin moisturizing function improving agent containing cyclic dipeptide as active ingredient - Google Patents

Description

  The present invention relates to a skin moisturizing function improving agent containing a specific cyclic dipeptide or a salt thereof as an active ingredient. More specifically, a skin moisturizing function improving agent comprising a specific cyclic dipeptide having an amino acid as a structural unit or a salt thereof as an active ingredient, use of the agent for improving the skin moisturizing function, and improving the skin moisturizing function. On how to do. The invention also relates to compositions containing certain cyclic dipeptides.

  A “dipeptide” in which two amino acids are bonded has attracted attention as a functional substance. Dipeptides can add physical properties and new functions not found in simple amino acids, and are expected to have a range of applications beyond amino acids. The physiological activity exhibited by dipeptides contained in milk, wheat, sesame, soybeans, pork, sardines and the like has been reported so far. There is a report (Non-patent Document 1) that the progression of arteriosclerosis is suppressed by administering a dipeptide (Trp-His) in which tryptophan and histidine are bound to an animal. In addition, as a component related to beauty, collagen synthesis is used for prolyl hydroxyproline (Pro-Hyp) and leucylhydroxyproline (Leu-Hyp), which are dipeptides detected in blood at high concentrations after oral intake of collagen peptides. A promoting action has been reported, and intake of collagen peptide is expected to contribute to the maintenance and enhancement of skin elasticity (Patent Document 1). Such dipeptides are used as active ingredients of pharmaceuticals and the like for the purpose of maintaining health and preventing / ameliorating lifestyle-related diseases.

  In recent years, diketopiperazine derivatives, which are cyclic dipeptides having a cyclic structure generated by dehydration condensation of an amino group and a carboxyl group present at the end of a dipeptide, have been developed. The cyclic dipeptide has been reported to have various physiological activities, and demand is expected to expand in the medical and pharmacological fields. For example, Patent Document 2 reports that a cyclic dipeptide having a 2,5-diketopiperazine structure has an antidepressant action, a learning motivation improving action, and the like. In Non-Patent Document 2, cyclic dipeptide [Cyclo (His-Pro)] suppresses central nervous system effects such as lowering body temperature and suppressing appetite, suppressing prolactin secretion, and growth hormone secretion. It is described that it exhibits many physiological activities such as promoting hormone-like effects, such as cyclic dipeptides [Cyclo (Leu-Gly)] exhibiting an improved memory function, and cyclic dipeptides [Cyclo (Asp-Pro)] It has been reported that it exhibits an action to suppress fat preference. Non-Patent Document 3 discloses an anti-cancer effect on cyclic dipeptide [Cyclo (Trp-Pro)], an antibacterial action on cyclic dipeptide [Cyclo (His-Pro)] and [Cyclo (Gly-Pro)], and a cyclic dipeptide [ Cyclo (His-Pro)] is neuroprotective, cyclic dipeptide [Cyclo (Gly-Pro)] is memory function improving, cyclic dipeptide [Cyclo (Tyr-Pro)] and [Cyclo (Phe-Pro)] are biological It is described that it acts as a herbicide. However, regarding the physiological activity of the cyclic dipeptide, it is thought that there are still many unclear functions.

JP 2010-024200 A Special table 2012-517998 gazette

British Journal of Nutrition, 103 (3), 309-313, 2010 Bioscience and industry, 60 (7), 454-457, 2002 Chemical Reviews, 112, 3641-3716, 2012

  An object of the present invention is to provide an agent having an action for improving the skin moisturizing function, use of the agent for improving the skin moisturizing function, and a method for improving the skin moisturizing function.

  As a result of intensive studies, the present inventors have found that cyclic dipeptides are higher in fat solubility and better in gastrointestinal permeability and membrane permeability than linear dipeptides. Furthermore, the specific cyclic dipeptide has an action to promote serine palmitoyltransferase (SPT) gene expression, an action to promote filaggrin gene expression, an action to promote hyaluronic acid synthase 3 gene expression, and an action to promote transglutaminase 3 gene expression. As a result, it was considered that the moisture retention function of the skin was remarkably improved, and the present invention was completed.

That is, the present invention relates to the following, but is not limited thereto.
(1). A skin moisturizing function improving agent comprising, as an active ingredient, a cyclic dipeptide or a salt thereof having an amino acid as a structural unit,
The agent, wherein the cyclic dipeptide or a salt thereof contains at least one amino acid selected from the group consisting of proline, hydroxyproline, alanine and glycine as a constituent unit.
(2). The agent according to (1), wherein the cyclic dipeptide or a salt thereof is cycloglycylhydroxyproline [Cyclo (Gly-Hyp)], cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycyl One or more selected from the group consisting of glycine [Cyclo (Gly-Gly)], cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala)] The said agent which is included.
(3). The agent according to (1) or (2), wherein the skin moisturizing function improving effect is caused by an increase in the production amount of ceramide.
(4). The agent according to (3), wherein the increase in the production amount of ceramide is caused by the promotion of expression of a serine palmitoyltransferase (SPT) gene.
(5). The agent according to (1) or (2), wherein the action of improving the moisturizing function of the skin is caused by the promotion of filaggrin gene expression.
(6). The agent according to (1) or (2), wherein the skin moisturizing function-improving action is caused by promoting expression of the hyaluronic acid synthase 3 gene.
(7). The agent according to (1) or (2), wherein the skin moisturizing function-improving action is caused by promoting expression of the transglutaminase 3 gene.
(8). The agent according to any one of (1) to (7), which has an effect of preventing rough skin.
(9). The agent according to any one of (1) to (8), which has an atopic dermatitis improving action.
(10). The composition containing the agent in any one of (1)-(9).
(11). The composition according to (10), which is labeled with a function exhibited by improving the skin moisturizing function.
(12). A composition in which the total amount of cyclic dipeptide or a salt thereof having amino acid as a structural unit is 1.0 × 10 ^{2 to} 1.0 × 10 ⁶ ppm,
The cyclic dipeptide or a salt thereof includes cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] and cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)],
The content of each of the cyclic dipeptides or salts thereof in the composition is
(I) Cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] or a salt thereof: 1.0 × 10 ^{2 to} 9.0 × 10 ⁵ ppm
(Ii) Cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)] or a salt thereof: 1.0 × 10 to 6.0 × 10 ⁵ ppm
Said composition.
(13). The composition according to (12),
The content of each of the cyclic dipeptides or salts thereof in the composition is
(I) Cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] or a salt thereof: 1.0 × 10 ^{3 to} 3.0 × 10 ⁵ ppm
(Ii) Cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)] or a salt thereof: 1.0 × 10 ^{2 to} 6.0 × 10 ⁴ ppm
Said composition.
(14). The composition according to (12),
The content of each of the cyclic dipeptides or salts thereof in the composition is
(I) Cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] or a salt thereof: 5.0 × 10 ^{3 to} 3.0 × 10 ⁴ ppm
(Ii) Cyclohydroxyprolyl glutamic acid [Cyclo (Hyp-Glu)] or a salt thereof: 4.0 × 10 ^{2 to} 6.0 × 10 ³ ppm
Said composition.
(15). The composition according to any one of (12) to (14),
The cyclic dipeptide or a salt thereof further comprises cycloglycylglycine [Cyclo (Gly-Gly)], cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala)]. Including one or more selected from the group,
Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof, cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof, and cycloprolylalanine [Cyclo (Pro-Ala)] in the composition Or the salt content is
(Iii) Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof: 1.0 × 10 to 8.0 × 10 ⁵ ppm
(Iv) Cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof: 1.0 × 10 to 9.0 × 10 ⁵ ppm
(V) Cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof: 1.0 × 10 to 9.0 × 10 ⁵ ppm
Said composition.
(16). (15) The composition according to
Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof, cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof, and cycloprolylalanine [Cyclo (Pro-Ala)] in the composition Or the salt content is
(Iii) Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof: 1.0 × 10 ^{2 to} 8.0 × 10 ⁴ ppm
(Iv) Cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof: 1.0 × 10 ^{2 to} 1.0 × 10 ⁵ ppm
(V) Cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof: 1.5 × 10 ^{2 to} 1.0 × 10 ⁵ ppm
Said composition.
(17). (15) The composition according to
Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof, cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof, and cycloprolylalanine [Cyclo (Pro-Ala)] in the composition Or the salt content is
(Iii) Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof: 6.0 × 10 ^{2 to} 8.0 × 10 ³ ppm
(Iv) Cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof: 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ ppm
(V) Cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof: 1.5 × 10 ^{3 to} 1.0 × 10 ⁴ ppm
Said composition.
(18). A composition in which the total amount of cyclic dipeptide or a salt thereof having amino acid as a structural unit is 1.0 × 10 ^{2 to} 1.0 × 10 ⁶ ppm,
The cyclic dipeptide or a salt thereof may be cycloglycylhydroxyproline [Cyclo (Gly-Hyp)], cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)], cyclohexane. Including prolyl hydroxyproline [Cyclo (Pro-Hyp)] and cycloprolyl alanine [Cyclo (Pro-Ala)],
The content of each of the cyclic dipeptides or salts thereof in the composition is
(I) Cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] or a salt thereof: 5.0 × 10 ^{3 to} 3.0 × 10 ⁴ ppm
(Ii) Cyclohydroxyprolyl glutamic acid [Cyclo (Hyp-Glu)] or a salt thereof: 4.0 × 10 ^{2 to} 6.0 × 10 ³ ppm
(Iii) Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof: 6.0 × 10 ^{2 to} 8.0 × 10 ³ ppm
(Iv) Cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof: 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ ppm
(V) Cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof: 1.5 × 10 ^{3 to} 1.0 × 10 ⁴ ppm
Said composition.
(19). The composition according to any one of (12) to (18), wherein the cyclic dipeptide having an amino acid as a structural unit or a salt thereof is obtained from collagen.
(20). The composition according to any one of (12) to (19), which is labeled with a function exhibited by improving the skin moisturizing function.
(21). The composition according to any one of (12) to (20), which is a food or drink.
(22). Use of a cyclic dipeptide having an amino acid as a structural unit or a salt thereof for improving the skin moisturizing function,
The cyclic dipeptide or a salt thereof may be cycloglycylhydroxyproline [Cyclo (Gly-Hyp)], cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)], cyclohexane. The use as described above, comprising one or two or more selected from the group consisting of prolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala)].
(23). A method for improving the skin moisturizing function, using as an active ingredient a cyclic dipeptide having amino acid as a structural unit or a salt thereof,
The cyclic dipeptide or a salt thereof may be cycloglycylhydroxyproline [Cyclo (Gly-Hyp)], cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)], cyclohexane. The method as described above, which comprises one or more selected from the group consisting of prolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala)].

  According to the present invention, a specific cyclic dipeptide or a salt thereof can be used as an agent for improving the moisture retention function of the skin. In the present invention, the effect of increasing ceramide production resulting from the SPT gene expression promoting action of a specific cyclic dipeptide or a salt thereof, and the increase of filaggrin production accompanying the action of promoting the expression of a filaggrin gene possessed by a specific cyclic dipeptide or a salt thereof By using the effect, an excellent moisturizing effect can be obtained, and an effect of improving dry skin and rough skin can be achieved. The improvement of the moisturizing function of the skin according to the present invention leads to providing a new means for improving the symptoms of atopic dermatitis and ichthyosis vulgaris.

FIG. 1 shows the effect of cyclic dipeptide on the expression of SPT gene involved in ceramide synthesis. FIG. 2 shows the effect of cyclic dipeptide on filaggrin gene expression. FIG. 3 shows the permeability of linear and cyclic dipeptides to the Caco-2 cell membrane.

  One embodiment of the present invention is an agent for improving the skin moisturizing function, which comprises a specific cyclic dipeptide or a salt thereof as an active ingredient. In the present specification, cyclic dipeptides or salts thereof may be collectively referred to simply as cyclic dipeptides.

<Cyclic dipeptide>
The cyclic dipeptide as used herein is characterized by having an amino acid as a structural unit, and means a dipeptide having a diketopiperazine structure formed by dehydration condensation of an amino group and a carboxyl group of an amino acid. In the present specification, as long as the amino acid composition of the cyclic dipeptide is the same, any order thereof may be used, for example, [Cyclo (Pro-Hyp)] and [Cyclo (Hyp-Pro)]. Represent the same cyclic dipeptide.

  Cyclic dipeptides have two amino acid terminal moieties attached via an amide bond, so they are more lipophilic than linear dipeptides that have a polar carboxyl group or amino group exposed at the molecular end. Is characterized by high. Therefore, when used as a skin external preparation, higher skin permeability can be expected as compared with a linear dipeptide.

  The present invention comprises a cyclic dipeptide containing at least one amino acid selected from the group consisting of proline, hydroxyproline, alanine and glycine as a structural unit or a salt thereof as an active ingredient. More preferably, cycloglycylhydroxyproline [Cyclo (Gly-Hyp)], cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)], cycloprolylhydroxyproline A cyclic dipeptide containing at least one selected from the group consisting of [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof as an active ingredient. is there.

  Among these, from the viewpoint of the effect of increasing ceramide production, cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] is particularly preferable as the cyclic dipeptide which is an active ingredient. In addition, from the viewpoint of the effect of promoting the expression of filaggrin gene, cyclic dipeptides which are active ingredients include cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)], cycloprotein. Rylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala)] are particularly preferred.

  In the present specification, the salt of the cyclic dipeptide refers to any pharmacologically acceptable salt of the cyclic dipeptide (including inorganic salts and organic salts), for example, sodium salt, potassium salt of the cyclic dipeptide, Calcium salt, magnesium salt, ammonium salt, hydrochloride, sulfate, nitrate, phosphate, organic acid salt (acetate, citrate, maleate, malate, oxalate, lactate, succinate, Fumarate, propionate, formate, benzoate, picrate, benzenesulfonate, and the like), but are not limited thereto. Cyclic dipeptide salts can be readily prepared by those skilled in the art by any method known in the art.

  The cyclic dipeptide used in the present invention can be prepared according to a method known in the art. For example, it may be produced by a chemical synthesis method, an enzymatic method, or a microbial fermentation method, or may be synthesized by dehydration and cyclization of a linear peptide, as disclosed in JP 2003-252896 A, Journal of Peptide Science, 10, 737-737, 2004. For example, collagen or a collagen peptide obtained by enzymatic treatment or heat treatment of collagen, and a treatment product obtained by further heat treatment can be used as an active ingredient. That is, in the present invention, the cyclic dipeptide having an amino acid as a structural unit may be obtained from collagen. Moreover, if the specific cyclic dipeptide in the processed collagen product does not satisfy a specific content, the specific cyclic dipeptide that is deficient can be added as appropriate.

  Specifically, the treatment product obtained by heat treating a solution containing collagen or collagen peptide is, for example, a condition in which collagen peptide is dissolved in water at a concentration of 20 to 500 g / mL, preferably at a temperature higher than 100 ° C. And heated for 5 minutes to 120 hours, preferably 3 to 10 hours. Moreover, it can heat at 100-170 degreeC more preferably, More preferably, it is 110-150 degreeC, More preferably, it can heat at 120-140 degreeC. Furthermore, the heating time is more preferably 30 to 600 minutes, and even more preferably about 180 to 600 minutes. Therefore, as a preferable specific example, a collagen peptide is dissolved in water at a concentration of 20 to 500 g / mL and prepared by heating at 100 to 170 ° C. for 3 to 10 hours. If necessary, the obtained processed product may be subjected to treatments such as filtration, centrifugation, concentration, ultrafiltration, lyophilization, and powdering.

  The cyclic dipeptide or salt thereof obtained as described above improves the moisturizing function of the skin by increasing the production amount of ceramide and / or filaggrin.

<Ceramide and serine palmitoyltransferase (SPT)>
In the present specification, ceramide is a kind of sphingolipid, and is composed of sphingolipid, glycosphingolipid, or a mixture thereof. Ceramide plays an important role in the skin moisturizing function and barrier function in the stratum corneum, which is the outermost layer of the skin. Ceramide is also known to have a skin moisturizing effect by constructing an intercellular lamellar structure in the stratum corneum after being produced and secreted in epidermal cells, and has a skin protective effect and a rough skin preventing effect. It has been. In skin diseases such as dry skin, rough skin, atopic dermatitis, senile psoriasis and psoriasis, normal metabolism of ceramide is impeded, the amount of ceramide in the stratum corneum is reduced, skin moisturizing function and barrier function It has been reported a lot that causes the decrease of Therefore, if ceramide production in epidermal cells can be increased and the amount of ceramide in the stratum corneum can be increased, the skin's moisturizing function and barrier function can be enhanced, skin diseases associated with a decrease in the amount of ceramide in the stratum corneum, For example, it is useful for the prevention and improvement of dry skin, rough skin, atopic dermatitis, senile psoriasis and psoriasis.

  In this specification, serine palmitoyltransferase (SPT) refers to an enzyme involved in the synthesis of ceramide. In the first stage of ceramide synthesis, it is known that palmitoyl CoA and a non-essential amino acid L-serine are condensed by SPT to produce 3-ketosphinganine. In ceramide synthase-deficient mice (SPT knockout mice), ceramide levels in the epidermis are reduced compared to wild-type mice, resulting in deterioration of the moisturizing function (Journal of Investigative Dermatology, 133 (11), 2555-2565, 2013). Therefore, by promoting the expression of the SPT gene, ceramide production in the body is increased, and an effect of improving the skin moisturizing function can be obtained.

<Filagrin>
In the present specification, filaggrin refers to a filament aggregating protein and is a protein having a molecular weight of about 40 kDa that plays an important role in the formation of the stratum corneum. In particular, it is known to play an important role in promoting epidermal differentiation and maintaining the barrier function of the skin. It has been reported that filaggrin is involved in various skin diseases, and mutations in the filaggrin gene are a major factor in the development of atopic dermatitis and ichthyosis vulgaris (Nature Genetics, 38, 441-446, 2006). In addition, it is known that the nociceptin antagonist JTC801 promotes the expression of filaggrin protein and improves the symptoms of atopic dermatitis (Journal of Allergy and Clinical Immunology, 133 (1), 139-146.e1-10 , 2014). Furthermore, it has been reported that aqueous solvent extracts of plants such as matababi, noni, bonito and oil tea increase filaggrin production.

<Hyaluronic acid synthase 3>
In this specification, hyaluronan synthase 3 (HAS3) is one of the three isoforms (HAS1, HAS2, HAS3) of hyaluronan synthase present in mammals. Is involved in hyaluronic acid synthesis. Here, hyaluronic acid is a kind of mucopolysaccharide present in the living body. Since this hyaluronic acid has high water retention, it improves skin moisturizing function, prevents wrinkles and sagging, maintains skin and articular cartilage function, improves presbyopia and eyestrain, improves transport of various nutrients through cell activation, It plays an important role in alleviating menstrual pain and improving menopause. Therefore, by promoting the expression of HAS3, the amount of hyaluronic acid in the living body is increased, and the effect of improving the skin moisturizing function can be obtained.

<Transglutaminase 3>
In this specification, transglutaminase 3 is a kind of enzyme mainly involved in cross-linking between proteins, and exists in a wide variety of organisms ranging from microorganisms to mammals. In particular, it is abundant in the skin, and plays a role of enhancing the barrier function of the skin or enhancing the moisturizing function by forming a cross-link between proteins present in the skin. Therefore, by promoting the expression of transglutaminase 3, an effect of improving the barrier function and the moisturizing function can be obtained.

<Skin moisturizing function improving agent>
The improvement of the skin moisturizing function referred to in this specification can be objectively evaluated such as an increase in stratum corneum water content, a decrease in transepidermal water loss (TEWL), skin findings, and the degree of itching. It means that the moisture retention function of the skin is improved based on the index.

  The skin moisturizing function improving agent of the present invention increases the production amount of ceramide. Specifically, the skin moisturizing function improving agent of the present invention promotes the expression of the SPT gene involved in the synthesis of ceramide. Therefore, the skin moisturizing function improving effect of the agent of the present invention is attributed to the SPT gene expression promoting action involved in the synthesis of ceramide and the subsequent increase in the production amount of ceramide.

  Moreover, the skin moisturizing function-improving agent of the present invention increases the production amount of filaggrin that plays an important role in the formation of the stratum corneum. Specifically, the skin moisturizing function improving agent of the present invention promotes the expression of filaggrin gene. Therefore, the skin moisturizing function improving effect of the agent of the present invention is attributed to the filaggrin gene expression promoting effect and the subsequent increase effect of filaggrin production.

The content of the cyclic dipeptide or the salt thereof in the skin moisturizing function improving agent of the present invention may be an amount that can achieve the desired effect of the present invention in consideration of its administration form, administration method, etc. It is not particularly limited. For example, when a collagen extract is used, the total content of the cyclic dipeptide or a salt thereof in the present invention is 1.0 × 10 ² ppm or more, preferably 5.0 × 10 ² ppm or more, more preferably 1.0 ×. It is 10 ³ ppm or more, preferably 1.0 × 10 ⁶ ppm or less, more preferably 1.0 × 10 ⁵ ppm or less. Further, in the skin moisturizing function improving agent, cycloglycylhydroxyproline [Cyclo (Gly-Hyp)], cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)] The content of cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala)], or the corresponding salt is as follows.
(1) Cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] or a salt thereof: 1.0 × 10 ^{2 to} 3.0 × 10 ⁶ ppm, preferably 1.0 × 10 ^{3 to} 3.0 × 10 ⁵ ppm, more preferably 5.0 × 10 ^{3 to} 3.0 × 10 ⁴ ppm, even more preferably 5.7 × 10 ^{3 to} 2.4 × 10 ⁴ ppm
(2) Cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)] or a salt thereof: 1.0 × 10 to 6.0 × 10 ⁵ ppm, preferably 1.0 × 10 ^{2 to} 6.0 × 10 ⁴ ppm , More preferably 4.0 × 10 ^{2 to} 6.0 × 10 ³ ppm, even more preferably 4.7 × 10 ^{2 to} 5.6 × 10 ³ ppm
(3) Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof: 1.0 × 10 to 8.0 × 10 ⁵ ppm, preferably 1.0 × 10 ^{2 to} 8.0 × 10 ⁴ ppm, More preferably 6.0 × 10 ^{2 to} 8.0 × 10 ³ ppm, and even more preferably 6.1 × 10 ^{2 to} 7.6 × 10 ³ ppm.
(4) Cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof: 1.0 × 10 to 1.0 × 10 ⁶ ppm, preferably 1.0 × 10 ^{2 to} 1.0 × 10 ⁵ ppm , More preferably 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ ppm, and even more preferably 1.5 × 10 ^{3 to} 8.5 × 10 ³ ppm
(5) Cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof: 1.0 × 10 to 1.0 × 10 ⁶ ppm, preferably 1.5 × 10 ^{2 to} 1.0 × 10 ⁵ ppm, More preferably 1.5 × 10 ^{3 to} 1.0 × 10 ⁴ ppm, and even more preferably 1.9 × 10 ^{3 to} 7.1 × 10 ³ ppm.
When a synthetic product or purified product is used as the cyclic dipeptide or a salt thereof, the total content of the cyclic dipeptide or a salt thereof in the skin moisturizing function improving agent of the present invention is not particularly limited. 0.0 × 10 ² ppm or more, preferably 5.0 × 10 ² ppm or more, more preferably 2.0 × 10 ³ ppm or more, and 2.5 × 10 ⁶ ppm or less, preferably 2.5 × 10 ^5. ppm or less, more preferably 2.5 × 10 ⁴ ppm or less. In addition, when a synthetic product or purified product is used as the cyclic dipeptide or a salt thereof, cycloglycylhydroxyproline [Cyclo (Gly-Hyp)], cyclohydroxyprolylglutamic acid, which is included in the skin moisturizing function improving agent of the present invention. [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)], cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala)], or The content of each corresponding salt is not particularly limited, but is, for example, 1.0 × 10 ² ppm or more, preferably 5.0 × 10 ² ppm or more, more preferably 2.0 × 10 ³ ppm. The above is 5.0 × 10 ⁵ ppm or less, preferably 5.0 × 10 ⁴ ppm or less, more preferably 5.0 × 10 ³ ppm or less, and even more preferably 4.4 × 10 ³ ppm or less. .

  The content of the cyclic dipeptide or a salt thereof can be measured according to a known method, and can be measured by, for example, subjecting it to LC-MS / MS.

In the present specification, cyclic dipeptides or salts thereof may be collectively referred to simply as cyclic dipeptides. Unless otherwise specified, “ppm” used in the present specification means ppm of weight / volume (w / v), and 1.0 ppm is converted to 1.0 × 10 ⁻³ mg / mL, It is converted to 1.0 × 10 ⁻⁴ wt%.

  The skin moisturizing function-improving agent of the present invention has the feature of containing an effective amount of the aforementioned cyclic dipeptide or a salt thereof, thereby increasing the production amount of ceramide and obtaining the effect of improving the skin moisturizing function. . In addition, the production amount of filaggrin can be increased to obtain a skin protecting effect and a rough skin preventing effect. Examples of diseases that require these effects include dry skin, rough skin, atopic dermatitis, senile xeroderma, vulgaris ichthyosis and psoriasis, and can be suitably used for the prevention and treatment of these diseases.

  The present invention can provide, for example, explicitly or implicitly indicating that it is used for prevention of rough skin, improvement of atopic dermatitis, improvement of skin moisturizing function, dry skin, rough skin and It is extremely useful for subjects with atopic dermatitis.

  Although this invention can be provided with the form of an agent as an example, it is not limited to this form. The skin moisturizing function improving agent of the present invention can also be provided as a composition containing the agent. As an example, it can be provided in the form of a medicine or the like, but is not limited to this form.

  According to the form, the agent of the present invention can contain any additive used in addition to the cyclic dipeptide or a salt thereof, and any component used in ordinary agents. Examples of these additives and / or components include vitamins such as vitamin E and vitamin C, physiologically active components such as minerals, nutritional components, and fragrances, as well as excipients and binders incorporated in the formulation. , Emulsifiers, tonicity agents (isotonic agents), buffers, solubilizers, preservatives, stabilizers, antioxidants, colorants, coagulants, coating agents, and the like, but are not limited thereto.

  The skin moisturizing function-improving agent of the present invention can be applied to any therapeutic use (medical use) or non-therapeutic use (non-medical use). Specific examples include pharmaceuticals, quasi-drugs, cosmetics, etc., and those that do not belong to these under the Pharmaceutical Affairs Law, but are used as compositions that explicitly or implicitly promote moisturizing improvement effects. Or in dosage forms.

  The skin moisturizing function-improving agent of the present invention is administered by an appropriate method according to the form. For example, oral solid preparations such as tablets, coated tablets, granules, powders and capsules, oral liquid preparations such as internal liquids and syrups, parenterals such as injections, external preparations, suppositories and transdermal absorption agents However, it is not limited to these.

<External preparation for skin>
The skin moisturizing function-improving agent of the present invention can be used by applying to the skin as a skin external preparation in order to obtain the skin moisturizing function improving effect, skin roughening preventing effect, etc., as well as a poultice, cosmetic, bath preparation and subcutaneous. The dosage form as an injection can be arbitrarily selected according to the purpose. In particular, it can be widely used as cosmetics, and can be in the form of creams, ointments, emulsions, solutions, gels, powders, granules, etc., and packs, lotions, powders, sticks, etc. . The preparation forms are also wide forms such as aqueous solution system, solubilization system, emulsification system, powder system, oil liquid system, gel system, ointment system, aerosol system, water-oil two-layer system and water-oil-powder three-layer system. can do. In other words, if it is a basic cosmetic, face wash, lotion, lotion, milk, cream, gel, essence (beauty serum), pack, mask, massage agent, foundation, lipstick, bath preparation, shampoo, hair conditioner, hair tonic It can be widely used in forms such as ointments, pastes, and sheet products (absorbent articles such as sanitary products, wipes, wet tissues, etc.). And the dosage form and form of this invention are not limited to these.

  In addition, in making these dosage forms, various oil agents, surfactants, gelling agents, preservatives, antioxidants, solvents, alcohol, water, chelating agents, thickeners, ultraviolet absorbers, emulsion stabilizers, pH A regulator, a pigment, a fragrance, and the like can be appropriately blended.

  The dosage of the skin moisturizing function-improving agent of the present invention is not particularly limited, and is appropriately set depending on the form, administration method, purpose of use, and age, weight and symptom of the patient or animal to be administered. The effective human intake of the cyclic dipeptide of the present invention or a salt thereof in the present invention is not constant, but for example, it is preferably 10 mg or more, more preferably 100 mg or more per day for a human with a body weight of 50 kg. Further, administration may be performed once or several times within one day within a desired dose range. The administration period is also arbitrary. Here, the effective human intake of the cyclic dipeptide of the present invention or a salt thereof is the total intake of the cyclic dipeptide or a salt thereof showing an effective effect in humans, and the type of the cyclic dipeptide is not particularly limited.

  When an animal is administered to a subject, the amount used per day for about 20 g per mouse varies depending on conditions such as the content of the active ingredient in the agent, the state of the subject of application, body weight, sex, and age. However, the total amount of the cyclic dipeptide or its salt is preferably 10 mg / kg or more, more preferably 100 mg / kg or more.

<Cyclic dipeptide-containing composition>
One embodiment of the present invention is a composition containing a cyclic dipeptide having an amino acid as a structural unit or a salt thereof. The total content of the cyclic dipeptide or the salt thereof in the composition of the present invention is 1.0 × 10 ² ppm or more, preferably 5.0 × 10 ² ppm or more, more preferably 1.0 × 10 ³ ppm or more. Yes, 1.0 × 10 ⁶ ppm or less, preferably 1.0 × 10 ⁵ ppm or less.

  One embodiment of the present invention is a composition containing at least cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] and cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)] as a cyclic dipeptide or a salt thereof. More preferably, as the cyclic dipeptide or a salt thereof, cycloglycylglycine [Cyclo (Gly-Gly)], cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala) )]. A composition containing one or more selected from the group consisting of:

The cyclic dipeptide-containing composition of the present invention is a composition containing at least cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] and cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], It has the characteristics that each content in it is the following ranges.
(I) Cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] or a salt thereof: 1.0 × 10 ^{2 to} 9.0 × 10 ⁵ ppm, preferably 1.0 × 10 ^{3 to} 3.0 × 10 ⁵ ppm, more preferably 5.0 × 10 ^{3 to} 3.0 × 10 ⁴ ppm, even more preferably 5.7 × 10 ^{3 to} 2.4 × 10 ⁴ ppm
(Ii) Cyclohydroxyprolyl glutamic acid [Cyclo (Hyp-Glu)] or a salt thereof: 1.0 × 10 to 6.0 × 10 ⁵ ppm, preferably 1.0 × 10 ^{2 to} 6.0 × 10 ⁴ ppm , More preferably 4.0 × 10 ^{2 to} 6.0 × 10 ³ ppm, even more preferably 4.7 × 10 ^{2 to} 5.6 × 10 ³ ppm
Preferably, the cyclic dipeptide-containing composition of the present invention contains at least cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] and cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], One or two selected from the group consisting of glycylglycine [Cyclo (Gly-Gly)], cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala)] In the composition, cycloglycylglycine [Cyclo (Gly-Gly)], cycloprolylhydroxyproline [Cyclo (Pro-Hyp)], and cycloprolylalanine [Cyclo (Pro-Hyp)]. Ala)] is in the following range.
(Iii) Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof: 1.0 × 10 to 8.0 × 10 ⁵ ppm, preferably 1.0 × 10 ^{2 to} 8.0 × 10 ⁴ ppm, More preferably 6.0 × 10 ^{2 to} 8.0 × 10 ³ ppm, and even more preferably 6.1 × 10 ^{2 to} 7.6 × 10 ³ ppm.
(Iv) Cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof: 1.0 × 10 to 9.0 × 10 ⁵ ppm, preferably 1.0 × 10 ^{2 to} 1.0 × 10 ⁵ ppm , More preferably 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ ppm, and even more preferably 1.5 × 10 ^{3 to} 8.5 × 10 ³ ppm
(V) Cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof: 1.0 × 10 to 9.0 × 10 ⁵ ppm, preferably 1.5 × 10 ^{2 to} 1.0 × 10 ⁵ ppm, More preferably 1.5 × 10 ^{3 to} 1.0 × 10 ⁴ ppm, and even more preferably 1.9 × 10 ^{3 to} 7.1 × 10 ³ ppm.
Most preferably, the cyclic dipeptide-containing composition of the present invention is a composition in which the total amount of cyclic dipeptide having amino acid as a structural unit or a salt thereof is 1.0 × 10 ^{2 to} 1.0 × 10 ⁶ ppm, The cyclic dipeptide or a salt thereof may be cycloglycylhydroxyproline [Cyclo (Gly-Hyp)], cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)], cyclohexane. Proyl hydroxyproline [Cyclo (Pro-Hyp)] and cycloprolyl alanine [Cyclo (Pro-Ala)], the content of each of the cyclic dipeptide or its salt in the composition is in the following range Is a composition.
(I) Cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] or a salt thereof: 5.0 × 10 ^{3 to} 3.0 × 10 ⁴ ppm
(Ii) Cyclohydroxyprolyl glutamic acid [Cyclo (Hyp-Glu)] or a salt thereof: 4.0 × 10 ^{2 to} 6.0 × 10 ³ ppm
(Iii) Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof: 6.0 × 10 ^{2 to} 8.0 × 10 ³ ppm
(Iv) Cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof: 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ ppm
(V) Cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof: 1.5 × 10 ^{3 to} 1.0 × 10 ⁴ ppm
In the cyclic dipeptide in the composition of the present invention, the proportion of cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] is preferably 0.001% by weight or more, from the viewpoint of the effect of increasing ceramide production, 0.01% by weight % Or more is more preferable, and 0.1% by weight or more is more preferable. Moreover, although an upper limit is not specifically limited, From a viewpoint of solubilization performance, 90 weight% or less is preferable, 50 weight% or less is more preferable, 10 weight% or less is more preferable, 1 weight% or less is still more preferable. Cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)], cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo ( Pro-Ala)] is preferably 0.002% by weight or more, more preferably 0.02% by weight or more, and further preferably 0.2% by weight or more from the viewpoint of the effect of promoting the expression of filaggrin gene. . Moreover, although an upper limit is not specifically limited, From a viewpoint of solubilization performance, 90 weight% or less is preferable, 70 weight% or less is more preferable, 10 weight% or less is more preferable, 1 weight% or less is still more preferable.

  The composition of the present invention has various physiological effects. In particular, the ceramide production can be increased and the effect of improving the skin moisturizing function can be obtained by having the characteristic of containing an effective amount of the aforementioned specific cyclic dipeptide or a salt thereof. Further, by promoting the expression of the filaggrin gene and increasing the production amount of filaggrin, it is possible to obtain a skin protecting effect and a rough skin preventing effect. Examples of diseases that require these effects include dry skin, rough skin, atopic dermatitis, senile xeroderma, vulgaris ichthyosis and psoriasis, and can be suitably used for the prevention and treatment of these diseases.

  The composition of the present invention is, for example, expressly or implicitly used for improving the moisturizing function of the skin, and for preventing and / or improving dry skin, rough skin, and atopic dermatitis. It is extremely useful for dry skin, weak skin, atopic dermatitis, and the like.

  One aspect of the present invention is an extract composition containing the specific cyclic dipeptide or a salt thereof. The extract composition is, for example, a product prepared by processing the specific cyclic dipeptide or a material containing the constituent amino acids of the cyclic dipeptide, as it is, or by diluting, concentrating and purifying the preparation according to a known method. It is a composition containing, and it is formulated as it is, and it is not included in drugs, quasi drugs, or the Pharmaceutical Affairs Law, but as with drugs and quasi drugs, for example, dry skin and rough skin, It can be used as a raw material for compositions purchased with the expectation of the prevention and / or amelioration effect of atopic dermatitis, and compositions that explicitly or implicitly appeal for these prevention and / or improvement effects. For the content of each cyclic dipeptide or a salt thereof in the extract composition, see the above description.

  The composition of this invention can contain the arbitrary components used for an arbitrary additive and a normal agent in the raw material containing the said specific cyclic dipeptide or its salt, for example. Examples of these additives and / or ingredients include vitamins such as vitamin E and vitamin C, minerals, physiologically active ingredients such as nutrients and fragrances, as well as solvents, dispersants and emulsifiers incorporated in the formulation. , Buffers, stabilizers, excipients, binders, disintegrants, lubricants, and the like. Add these additives, etc., according to known methods, oral solid preparations such as tablets, coated tablets, granules, powders, capsules, oral liquid preparations such as oral liquids and syrups, injections, external preparations, It can be formulated into parenteral preparations such as suppositories and transdermal absorption agents, but is not limited thereto. Moreover, these compositions can be taken with water or the like as it is. Moreover, after preparing the form (for example, powder form and granule form) which can be mix | blended easily, it can use as raw materials, such as a pharmaceutical, a quasi-drug, cosmetics, food-drinks, etc., for example.

  The composition of the present invention can be arbitrarily selected depending on the purpose as a cosmetic agent such as a cataplasm, a cosmetic agent, a bath agent and a subcutaneous injection agent. In particular, it can be widely used as cosmetics, and can be in the form of creams, ointments, emulsions, solutions, gels, powders, granules, etc., and packs, lotions, powders, sticks, etc. . The preparation forms are also aqueous, solubilized, emulsified, powder, oil-liquid, gel, ointment, aerosol, water-oil two-layer and water-oil-powder three-layer. can do. In other words, if it is a basic cosmetic, face wash, lotion, lotion, milk, cream, gel, essence (beauty serum), pack, mask, massage agent, foundation, lipstick, bath preparation, shampoo, hair conditioner, hair tonic It can be widely used in forms such as ointments, pastes, and sheet products (absorbent articles such as sanitary products, wiping wipes, and wet tissues). And it is not limited to the dosage form and form of this invention.

  In addition, in making these dosage forms, various oil agents, surfactants, gelling agents, preservatives, antioxidants, solvents, alcohol, water, chelating agents, thickeners, ultraviolet absorbers, emulsion stabilizers, pH A regulator, a pigment, a fragrance, and the like can be appropriately blended.

  Although the composition of this invention is not specifically limited, For example, the pharmaceutical containing the said cyclic dipeptide or its salt, a quasi-drug, cosmetics, food-drinks (beverages, foodstuffs, etc.), etc. are mentioned. The content of the cyclic dipeptide or a salt thereof in these compositions is as described above.

  The beverage of the present invention may be prepared according to a known beverage production method by mixing a predetermined amount of the cyclic dipeptide or a salt thereof with the raw material when preparing a known beverage, for example, You may prepare by adding the said cyclic dipeptide or its salt to a well-known drink composition so that it may become the said predetermined amount, and melt | dissolving and / or suspending. In addition, a well-known drink may originally contain the said cyclic dipeptide or its salt, and if the cyclic dipeptide of this invention becomes a predetermined amount, it can mix | blend and prepare suitably.

  Specific examples of the beverage of the present invention include oolong tea beverage, black tea beverage, green tea beverage, fruit juice beverage, vegetable juice, sports drink, isotonic beverage, enhanced water, mineral water, near water, nutritional drink, beauty drink, various alcohols A drink etc. can be mentioned. In addition, the beverage may contain an antioxidant, a fragrance, an organic acid, an organic acid salt, an inorganic acid, an inorganic acid salt, an inorganic salt, a pigment, an emulsifier, a preservative, a seasoning, a sweetener, and an acidity as necessary. Additives such as ingredients, gums, oils, vitamins, amino acids, fruit juice extracts, vegetable extracts, pH adjusters, and quality stabilizers may be used alone or in combination.

  One aspect of the present invention is a food containing the cyclic dipeptide or a salt thereof. A food is a composition used mainly for ingestion by meals and snacks. The content of the cyclic dipeptide or a salt thereof in the food of the present invention is as described above.

  The food of the present invention may be prepared according to a known food production method, for example, by mixing a predetermined amount of the cyclic dipeptide or a salt thereof with the raw material when preparing a known food. You may prepare by adding the said cyclic dipeptide or its salt to a well-known food so that it may become the said predetermined amount. In addition, a well-known food may originally contain the said cyclic dipeptide or its salt, and if the cyclic dipeptide of this invention becomes a predetermined amount, it can mix | blend and prepare suitably.

  Specific examples of the food of the present invention include, for example, health foods, functional foods (including special health foods, conditional special health foods, and nutritional functional foods), special-purpose foods, health supplements, and the like. .

  The composition of the present invention can be applied by an appropriate method according to the form. The application method is not particularly limited, but includes all aspects such as ingestion, taking, drinking, and application.

  The composition of the present invention is, for example, expressly or implicitly used for improving the moisturizing function of the skin, and for preventing and / or improving dry skin, rough skin, and atopic dermatitis. It is extremely useful for dry skin, weak skin, atopic dermatitis, and the like.

  In another aspect, the present invention relates to the composition, which is labeled with a function exhibited by improving the skin moisturizing function. Such display or function display is not particularly limited. For example, “improving moisture retention of skin”, “maintaining moisture retention of skin”, “maintaining skin moisture”, “maintaining skin beauty” ”,“ Prevent dry skin ”,“ Improve dry skin ”,“ Prevent rough skin ”,“ Improve rough skin ”,“ Prevent atopic dermatitis ”, or“ Improve atopic dermatitis ” And so on. In the present invention, indications such as the indication and the function indication may be attached to the composition itself, or may be attached to a container or packaging of the composition.

  In the present specification, the subject of ingestion of the composition of the present invention is preferably a human, but domestic animals such as cattle, horses and goats, pet animals such as dogs, cats and rabbits, or mice, rats and guinea pigs. Or a laboratory animal such as a monkey.

  The intake of the composition of the present invention is appropriately set depending on the form, administration method, purpose of use, and age, weight, and symptom of the patient or patient who is the intake target of the composition, and is not particularly limited. The effective human intake of the specific cyclic dipeptide or a salt thereof in the present invention is not constant, but for example, it is preferably 10 mg or more, more preferably 100 mg or more, per day for a human weighing 50 kg. Further, the administration may be performed once or divided into several times within one day within a desired dose range. The administration period is also arbitrary. Here, the effective human intake of the specific cyclic dipeptide or a salt thereof is the total intake of the cyclic dipeptide or a salt thereof showing an effective effect in humans.

  When an animal is administered to a subject (relative to about 20 g per mouse), the amount used per day is the content of the active ingredient in the composition, the state of the subject of application, body weight, sex, age, etc. Usually, the total amount of cyclic dipeptide or a salt thereof is preferably 10 mg / kg or more, more preferably 100 mg / kg or more, although it varies depending on conditions.

<Use to improve skin moisturizing function>
One embodiment of the present invention is to use a specific cyclic dipeptide having an amino acid as a structural unit or a salt thereof for improving the moisturizing function of the skin. Preferably, a cyclic dipeptide or a salt thereof containing at least one amino acid selected from the group consisting of proline, hydroxyproline, alanine and glycine, more preferably cycloglycylhydroxyproline [Cyclo (Gly-Hyp)], cyclo Hydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)], cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala )], One or more cyclic dipeptides or salts thereof are used to improve the skin moisturizing function. Examples include, but are not limited to, use for preventing or treating dry skin, rough skin, atopic dermatitis, senile xeroderma, ichthyosis vulgaris and psoriasis. The use is in a human or non-human animal and may be a therapeutic or non-therapeutic use. Here, “non-therapeutic” is a concept that does not include a medical act, that is, a treatment act on the human body by treatment.

<Method of improving skin moisturizing function>
The present invention also provides a method of improving skin moisturizing function comprising administering to an individual in need of improving skin moisturizing function, an effective amount of a specific cyclic dipeptide or a salt thereof. Preferably, a cyclic dipeptide or a salt thereof containing at least one amino acid selected from the group consisting of proline, hydroxyproline, alanine and glycine, more preferably cycloglycylhydroxyproline [Cyclo (Gly-Hyp)], cyclo Hydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)], cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala )] Is provided, comprising administering a therapeutically effective amount of one or more cyclic dipeptides or salts thereof, or a composition containing these components, to improve the skin moisturizing function Is. The individual requiring improvement of the skin moisturizing function is the same as the administration subject of the skin moisturizing function improving agent of the present invention.

  In the present specification, the therapeutically effective amount refers to an amount that improves skin moisturizing when the cyclic dipeptide of the present invention or a salt thereof is administered to the individual as compared to an individual that is not administered. . The specific effective amount is appropriately set according to the administration form, administration method, purpose of use, age, weight, symptoms, etc. of the individual and is not constant.

  In the method of the present invention, the specific cyclic dipeptide or a salt thereof may be administered as it is or as a composition containing the specific cyclic dipeptide or a salt thereof so that the therapeutically effective amount is obtained.

  According to the method of the present invention, it is possible to improve the skin moisturizing function without causing side effects.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this does not limit the scope of the present invention. Those skilled in the art can use the method of the present invention with various changes and modifications, and these are also included in the scope of the present invention.
Example 1: Effect of cyclic dipeptide on expression of SPT gene (SPTLC1) involved in ceramide synthesis pathway in human epidermal keratinocytes (FIG. 1)
Normal human epidermal keratinocytes (NHEK) are seeded in a 12-well plate (Corning) at 1.0 × 10 ⁵ cells / mL / well, cultured in KGM (Lonza), a special medium, for 24 hours, and then the final concentration The cyclic dipeptide was added so as to be 500 μM. The cyclic dipeptide was synthesized by commissioning at Kobe Natural Products Chemical Co., Ltd. After 24 hours, RNA was extracted from the cells using isogen (Nippon Gene), and the RNA was purified using RNeasy Mini Kit (Quiagen). CDNA was synthesized using High-Capacity cDNA Reverse Transcription Kit (Lifetechnologies), and the expression of the gene was examined by quantitative PCR using Fast Universal PCR Master Mix (Lifetechnologies). In the analysis, the comparative Ct method using the Gapdh gene as an internal standard gene was applied. The expression level of the gene is shown as a relative expression level with respect to the sample non-added group. Data were expressed as mean ± standard error, and statistical test was significant at p <0.05 using Student's t-test.

As shown in Fig. 1, as a result of adding Cyclo (Gly-Hyp) to NHEK cells and culturing for 24 hours, the expression level of SPT gene (SPTLC1) in the cells is significantly increased compared to the sample-free group Was shown to do.
Example 2: Effect of cyclic dipeptide on filaggrin gene expression in human epidermal keratinocytes (FIG. 2)
The test was carried out according to Example 1.

As a result of the test, as shown in FIG. 2, Cyclo (Gly-Gly), Cyclo (Pro-Hyp), Cyclo (Pro-Ala) and Cyclo (Hyp-Glu) were added to NHEK cells and cultured for 24 hours. As a result, it was shown that the level of intracellular filaggrin gene expression increased significantly compared to the non-added group. It was also shown that the increase in filaggrin gene expression was greatest when Cyclo (Hyp-Glu) was added.
Example 3: Evaluation of Caco-2 cell membrane permeability of linear and cyclic dipeptides (Fig. 3)
Membrane permeability through Caco-2 cell monolayer membrane, which is commonly used for evaluating the absorbability of compounds as gastrointestinal model cells, was evaluated. Caco-2 cells cultured for 25-35 days on a transwell (Corning, 24 well, diameter 6.5 mm) were subjected to the test. The test was started by adding a buffer containing linear Pro-Hyp (Bachem Feinchemikalien AG) or cyclic Pro-Hyp at a concentration of 30 μg / mL to the luminal side (Apical side). After 60 minutes from the basal side (basal side), 120 minutes later, the buffer was recovered, the compound concentration was quantified by LC-MS / MS, and membrane permeability was analyzed. The membrane permeability was evaluated by the value (unit: μL) obtained by dividing the total permeation amount (ng) by the initial concentration (μg / mL).

As a result of the experiment, as shown in FIG. 3, it was shown that the linear Pro-Hyp has extremely low membrane permeability to the Caco-2 cell monolayer and hardly permeates the membrane. On the other hand, cyclic Pro-Hyp is shown to permeate to the basement membrane side over time after being added to the luminal side of Caco-2 cell monolayer, and the membrane permeability of cyclic Pro-Hyp is high Has been demonstrated. This result showed that cyclic Pro-Hyp has higher gastrointestinal permeability and membrane permeability than linear Pro-Hyp.
Example 4: Effect of cyclic dipeptide on hyaluronic acid synthase 3 (HAS3) gene expression in normal human dermal fibroblasts (NHDF) Normal human dermal fibroblasts (NHDF) in DMEM medium (37 ° C, 10% FBS) The cells were seeded at a concentration of 5.0 × 10 ⁵ cells / well in a 6-well microplate using 5% CO ₂ ), and pre-cultured until subconfluent. Next, cyclic dipeptide (4 concentrations) and positive target (N-acetylglucosamine, 1 concentration) were added and further cultured for 24 hours, then washed once with PBS (-), and NucleoSpin (R) RNA RNA was extracted by (Takara Bio). Using the extracted RNA, a reverse transcription reaction was performed with PrimeScript® RT Master Mix (Takara Bio) to prepare cDNA. Thereafter, the expression of the gene was examined by quantitative PCR using SYBR (R) Premix Ex Taq II (Takara Bio). In the analysis, the comparative Ct method using the Gapdh gene as an internal standard gene was applied. The expression level of the gene is shown as a relative expression level with respect to the sample non-added group. Table 1 shows the relative values (expression ratio, standard deviation) when the gene expression level of the sample non-addition group is 1.

As a result of experiments, the mRNA expression level of hyaluronic acid synthase (HAS) 3 involved in the maintenance of the skin barrier function and moisturizing function increased for a plurality of cyclic dipeptide preparations and positive controls.
Example 5: Effect of cyclic dipeptide on transglutaminase 3 (TGM3) gene expression in normal human epidermal keratinocytes (NHEK) Normal human epidermal keratinocytes (NHEK) in Epilife-KG2 medium (37 ° C, containing 10% FBS) The cells were seeded at a concentration of 5.0 × 10 ⁵ cells / well in a 6-well microplate using 5% CO ₂ ), and pre-cultured until subconfluent. Next, after adding a test product (4 concentrations) and a positive target (prolactin, 1 concentration) and further culturing for 24 hours, the cells were washed once with PBS (-) and NucleoSpin (R) RNA (Takara Bio) ) To extract RNA. Using the extracted RNA, a reverse transcription reaction was performed with PrimeScript® RT Master Mix (Takara Bio) to prepare cDNA. Thereafter, the expression of the gene was examined by quantitative PCR using SYBR (R) Premix Ex Taq II (Takara Bio). In the analysis, the comparative Ct method using the Gapdh gene as an internal standard gene was applied. The expression level of the gene is shown as a relative expression level with respect to the sample non-added group. Table 2 shows the relative values (expression ratio, standard deviation) when the gene expression level of the sample non-added group is 1. In Table 2, “Hylys” means an abbreviation of “hydroxylysine”.

  As a result of the experiment, the mRNA expression level of transglutaminase (TGM) 3 involved in maintaining the skin barrier function and the moisturizing function increased for a plurality of cyclic dipeptide preparations and positive controls.

  The present invention provides an agent for improving the skin moisturizing function, which utilizes the effect of increasing the production of ceramide and filaggrin possessed by a specific cyclic dipeptide. Since cyclic dipeptide has high fat solubility and excellent gastrointestinal permeability and membrane permeability, a high moisturizing effect is obtained when used as an internal use or an external preparation. Therefore, since the present invention can provide an effective and new means for improving symptoms such as dry skin, rough skin, and atopic dermatitis, it is highly industrially applicable.

Claims (16)

A composition for improving the moisturizing function of the skin, wherein the total amount of cyclic dipeptide having amino acid as a structural unit or a salt thereof is 1.0 × 10 ^{2 to} 1.0 × 10 ⁶ ppm,
The cyclic dipeptide or a salt thereof includes cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] and cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)],
The content of each of the cyclic dipeptides or salts thereof in the composition is
(I) Cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] or a salt thereof: 1.0 × 10 ^{2 to} 9.0 × 10 ⁵ ppm
(Ii) Cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)] or a salt thereof: 1.0 × 10 to 6.0 × 10 ⁵ ppm
Said composition. A composition according to claim 1, comprising:
The content of each of the cyclic dipeptides or salts thereof in the composition is
(I) Cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] or a salt thereof: 1.0 × 10 ^{3 to} 3.0 × 10 ⁵ ppm
(Ii) Cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)] or a salt thereof: 1.0 × 10 ^{2 to} 6.0 × 10 ⁴ ppm
Said composition. A composition according to claim 1, comprising:
The content of each of the cyclic dipeptides or salts thereof in the composition is
(I) Cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] or a salt thereof: 5.0 × 10 ^{3 to} 3.0 × 10 ⁴ ppm
(Ii) Cyclohydroxyprolyl glutamic acid [Cyclo (Hyp-Glu)] or a salt thereof: 4.0 × 10 ^{2 to} 6.0 × 10 ³ ppm
Said composition. It is a composition as described in any one of Claims 1-3, Comprising:
The cyclic dipeptide or a salt thereof further comprises cycloglycylglycine [Cyclo (Gly-Gly)], cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] and cycloprolylalanine [Cyclo (Pro-Ala)]. Including one or more selected from the group,
Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof, cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof, and cycloprolylalanine [Cyclo (Pro-Ala)] in the composition Or the salt content is
(Iii) Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof: 1.0 × 10 to 8.0 × 10 ⁵ ppm
(Iv) Cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof: 1.0 × 10 to 9.0 × 10 ⁵ ppm
(V) Cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof: 1.0 × 10 to 9.0 × 10 ⁵ ppm
Said composition. A composition according to claim 4, wherein
Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof, cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof, and cycloprolylalanine [Cyclo (Pro-Ala)] in the composition Or the salt content is
(Iii) Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof: 1.0 × 10 ^{2 to} 8.0 × 10 ⁴ ppm
(Iv) Cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof: 1.0 × 10 ^{2 to} 1.0 × 10 ⁵ ppm
(V) Cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof: 1.5 × 10 ^{2 to} 1.0 × 10 ⁵ ppm
Said composition. A composition according to claim 4, wherein
Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof, cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof, and cycloprolylalanine [Cyclo (Pro-Ala)] in the composition Or the salt content is
(Iii) Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof: 6.0 × 10 ^{2 to} 8.0 × 10 ³ ppm
(Iv) Cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof: 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ ppm
(V) Cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof: 1.5 × 10 ^{3 to} 1.0 × 10 ⁴ ppm
Said composition. A composition for improving the moisturizing function of the skin, wherein the total amount of cyclic dipeptide having amino acid as a structural unit or a salt thereof is 1.0 × 10 ^{2 to} 1.0 × 10 ⁶ ppm,
The cyclic dipeptide or a salt thereof may be cycloglycylhydroxyproline [Cyclo (Gly-Hyp)], cyclohydroxyprolylglutamic acid [Cyclo (Hyp-Glu)], cycloglycylglycine [Cyclo (Gly-Gly)], cyclohexane. Including prolyl hydroxyproline [Cyclo (Pro-Hyp)] and cycloprolyl alanine [Cyclo (Pro-Ala)],
The content of each of the cyclic dipeptides or salts thereof in the composition is
(I) Cycloglycylhydroxyproline [Cyclo (Gly-Hyp)] or a salt thereof: 5.0 × 10 ^{3 to} 3.0 × 10 ⁴ ppm
(Ii) Cyclohydroxyprolyl glutamic acid [Cyclo (Hyp-Glu)] or a salt thereof: 4.0 × 10 ^{2 to} 6.0 × 10 ³ ppm
(Iii) Cycloglycylglycine [Cyclo (Gly-Gly)] or a salt thereof: 6.0 × 10 ^{2 to} 8.0 × 10 ³ ppm
(Iv) Cycloprolylhydroxyproline [Cyclo (Pro-Hyp)] or a salt thereof: 1.0 × 10 ^{3 to} 1.0 × 10 ⁴ ppm
(V) Cycloprolylalanine [Cyclo (Pro-Ala)] or a salt thereof: 1.5 × 10 ^{3 to} 1.0 × 10 ⁴ ppm
Said composition.   The composition according to any one of claims 1 to 7, wherein the cyclic dipeptide having an amino acid as a structural unit or a salt thereof is obtained from collagen.   The composition as described in any one of Claims 1-8 which attached | subjected the display of the function exhibited by the moisture retention function improvement of skin.   The composition according to any one of claims 1 to 9, which is a food or drink.   The composition according to any one of claims 1 to 10, wherein the skin moisturizing function improving effect is caused by an increase in the production amount of ceramide.   The composition according to claim 11, wherein the increase in the amount of ceramide produced is due to the enhanced expression of serine palmitoyltransferase (SPT) gene.   The composition according to any one of 1 to 10, wherein the skin moisturizing function improving action is caused by the promotion of filaggrin gene expression.   The composition according to any one of claims 1 to 10, wherein the action of improving the skin moisturizing function is caused by promoting expression of the hyaluronic acid synthase 3 gene.   The composition according to any one of claims 1 to 10, wherein the action of improving the skin moisturizing function is caused by the promotion of expression of the transglutaminase 3 gene.   The composition according to any one of claims 1 to 15, which has an effect of preventing rough skin.

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