JP7635905B2 - Desmoglein reducer - Google Patents

Description

The present invention relates to a desmoglein-reducing agent and an external skin preparation containing a desmoglein-reducing agent.

Increased levels of desmosomal proteins are known to be one of the causes of deterioration of skin conditions, such as rough skin and peeling of the stratum corneum caused by sunburn or dryness.
As a method for controlling the amount of desmosomal proteins, a method has been reported in which decomposition of desmosomal proteins accumulated in the stratum corneum with proteases is used to improve acne, dandruff, and desquamation (Patent Document 1).

Among desmosomal proteins, desmoglein in particular is known to be involved in adhesion between epidermal cells and keratinocytes (Patent Documents 2-4).

As a prior art, Patent Document 2 reports an agent for reducing desmoglein in stratum corneum cells, which contains astaxanthin.
Furthermore, Patent Document 4 reports an orally administered agent for inhibiting intercellular adhesion in the skin, which contains licorice extract as an active ingredient.

Incidentally, Patent Documents 5-7 report that extracts of Wild Thyme (T. serpyllum) and extracts of Thymus plants of the Lamiaceae family have effects of improving moisture retention, anti-inflammatory effects, preventing skin aging, and protecting against ultraviolet rays.

Special Publication No. 7-505383 JP 2016-37501 A Patent No. 4002635 Patent No. 4197194 JP 2001-122729 A JP 2006-16337 A JP 2009-256270 A

Given the above prior art, the objective of the present invention is to provide a new technology for reducing desmogleins.

As a result of intensive research, the inventors discovered that certain fatty acids or fatty acid derivatives have the effect of reducing desmoglein, and thus completed the present invention.

The present invention, which solves the above problems, is a desmoglein reducer containing as an active ingredient one or more selected from the group consisting of fatty acids, hydroxy fatty acids, and esters thereof, represented by any one of the following general formulas (1) to (4):
General formula (1)
C_nH_2nO_m(n = an integer of 18 or more, m = 2 or 3)

General formula (2)
C_nH_2n-2O_m(n = an integer of 18 or more, m = 2 or 3)

General formula (3)
C_nH_2n-4O_m(n = integer 19 or more, m = 2 or 3)

General formula (4)
C_nH_2n-6O_m(n = integer 18 or greater, m = 2 or 3)

In a preferred embodiment of the present invention, the active ingredient is one or more selected from the following Group A.
(Group A)
Saturated fatty acids having 18 or more carbon atoms or their esters, hydroxy monounsaturated fatty acids having 18 or more carbon atoms or their esters, esters of diunsaturated fatty acids having 18 or more carbon atoms

In a preferred embodiment of the present invention, the active ingredient is one or more selected from the following Group B:
(Group B)
Stearic acid, ricinoleic acid, methyl linoleate, methyl ricinoleate

In a preferred embodiment of the present invention, the desmoglein-reducing agent is used to inhibit intercellular adhesion of human epidermal keratinocytes.

In a preferred embodiment of the present invention, the desmoglein reducer is used to reduce desmoglein 1.

In a preferred embodiment of the present invention, the desmoglein reducer is used to prevent or improve sensitive skin.

In a preferred embodiment of the present invention, the desmoglein reducer is used to improve skin brightness.

In a preferred embodiment of the present invention, the desmoglein reducer is used to improve skin clarity.

In a preferred embodiment of the present invention, the desmoglein reducing agent is used to soften the skin.

In a preferred embodiment of the present invention, the desmoglein reducer is used to aid in the penetration of medicinal ingredients into the skin.

In a preferred embodiment of the present invention, the desmoglein reducing agent is used to improve and/or prevent stratum corneum desquamation.

The present invention, which solves the above problem, is a composition containing the desmoglein reducer.

In a preferred embodiment of the present invention, the composition is a cosmetic or a pharmaceutical.

The present invention makes it possible to reduce desmoglein present on human skin.

FIG. 1 shows the results of a control and examples of components 1 to 3. FIG. 1 shows the results of the examples of components 4 to 6. FIG. 1 shows the results of the examples of components 7 to 9.

(1) Active Ingredient The desmoglein-reducing agent of the present invention contains as an active ingredient one or more selected from the group consisting of fatty acids, hydroxy fatty acids, fatty acid esters, and hydroxy fatty acid esters represented by any one of the following general formulas (1) to (4):

General formula (1)
C_nH_2nO_m(n = an integer of 18 or more, m = 2 or 3)

General formula (2)
C_nH_2n-2O_m(n = an integer of 18 or more, m = 2 or 3)

General formula (3)
C_nH_2n-4O_m(n = integer 19 or more, m = 2 or 3)

General formula (4)
C_nH_2n-6O_m(n = integer 18 or greater, m = 2 or 3)

Examples of the compound represented by the general formula (1) include saturated fatty acids having 18 or more carbon atoms, hydroxy saturated fatty acids having 18 or more carbon atoms, and esters thereof.
Specific examples include saturated fatty acids such as stearic acid, arachidic acid, behenic acid, and lignoceric acid, hydroxy fatty acids such as hydroxystearic acid, hydroxyarachidic acid, hydroxybehenic acid, and hydroxylignoceric acid, and alkyl esters of these fatty acids or hydroxy fatty acids. The number of carbon atoms in the alkyl ester is not particularly limited, but it preferably has an alkyl group having 1 to 8 carbon atoms, more preferably has an alkyl group having 1 to 6 carbon atoms, even more preferably has an alkyl group having 1 to 4 carbon atoms, and particularly preferably has an alkyl group having 1 to 3 carbon atoms.
A preferred example of the compound represented by formula (1) is stearic acid.

Examples of the compound represented by the general formula (2) include monovalent unsaturated fatty acids having 18 or more carbon atoms, monovalent hydroxy unsaturated fatty acids having 18 or more carbon atoms, and esters of these.
Specific examples include monounsaturated fatty acids such as oleic acid, vaccenic acid, gadoleic acid, eicosenoic acid, erucic acid, etc., hydroxyunsaturated fatty acids such as ricinoleic acid, etc., and alkyl esters of these fatty acids or hydroxy fatty acids. The number of carbon atoms in the alkyl ester is not particularly limited, but it preferably has an alkyl group having 1 to 8 carbon atoms, more preferably has an alkyl group having 1 to 6 carbon atoms, even more preferably has an alkyl group having 1 to 4 carbon atoms, and particularly preferably has an alkyl group having 1 to 3 carbon atoms.
As the compound represented by the general formula (2), ricinoleic acid and methyl ricinoleate are preferred.

Examples of the compound represented by general formula (3) include divalent unsaturated fatty acids having 19 or more carbon atoms, divalent hydroxy unsaturated fatty acids having 19 or more carbon atoms, and esters of these. In addition, the compound may be a compound in which a hydrogen atom in the hydroxy group of a divalent hydroxy unsaturated fatty acid or an ester thereof is substituted with an alkyl group having 1 to 3 carbon atoms.
Specific examples include diunsaturated fatty acids such as eicosadienoic acid and docosadienoic acid, alkyl esters of diunsaturated fatty acids such as linoleic acid, eicosadienoic acid and docosadienoic acid, and alkyl esters of hydroxyunsaturated fatty acids such as methoprene. The number of carbon atoms in the alkyl ester is not particularly limited, but it preferably has an alkyl group having 1 to 8 carbon atoms, more preferably has an alkyl group having 1 to 6 carbon atoms, even more preferably has an alkyl group having 1 to 4 carbon atoms, and particularly preferably has an alkyl group having 1 to 3 carbon atoms.
As the compound represented by the general formula (3), methyl linoleate and methoprene are preferred, and methyl linoleate is more preferred.

Examples of the compound represented by the general formula (4) include trivalent unsaturated fatty acids having 18 or more carbon atoms, trivalent hydroxy unsaturated fatty acids having 18 or more carbon atoms, and esters of these.
Specific examples include trivalent unsaturated fatty acids such as linoleic acid, pinoleic acid, eleostearic acid, mead acid, and eicosatrienoic acid, and alkyl esters thereof. The number of carbon atoms in the alkyl ester is not particularly limited, but it is preferable that the alkyl ester has an alkyl group having 1 to 8 carbon atoms.
The compound represented by formula (4) is preferably linoleic acid.

The hydrocarbon chains in the compounds represented by the above general formulas (1) to (4) (including those in which some hydrogen atoms are replaced by hydroxyl groups) may be linear or branched.

The active ingredient in the desmoglein reducer of the present invention is preferably one or more components selected from the following Group A among the compounds represented by the above general formulas (1) to (4), and more preferably one or more components selected from the following Group A'.
(Group A)
Saturated fatty acids having 18 or more carbon atoms or their esters, hydroxy monounsaturated fatty acids having 18 or more carbon atoms or their esters, esters of diunsaturated fatty acids having 18 or more carbon atoms (Group A')
Saturated fatty acids having 18 or more carbon atoms, hydroxy monounsaturated fatty acids having 18 or more carbon atoms or their esters, esters of diunsaturated fatty acids having 18 or more carbon atoms

As the active ingredient, one or more selected from the following Group B are particularly preferred.
(Group B)
Stearic acid, ricinoleic acid, methyl linoleate, methyl ricinoleate

(2) Desmoglein-reducing Agent The desmoglein-reducing agent of the present invention preferably targets desmoglein 1 for reduction.

The desmoglein-reducing agent of the present invention is preferably used for improving and/or preventing sensitive skin.
Here, in this specification, "sensitive skin" refers to a skin type with reduced resistance to external stimuli (dryness, ultraviolet rays, application of chemical compounds) (reduced skin irritation threshold).

More specifically, "sensitive skin" in this specification refers to the skin types listed in (1) and/or (2).

(1) "Skin that reacts to substances such as topical medicines, cosmetics, plants, ultraviolet rays, and metals and is prone to skin problems. Also, skin that is hypersensitive to allergens (pollen, fragrances, etc.) and irritants (alcohol, etc.)."
(2) "Skin that is temporarily more susceptible to skin problems due to lack of sleep, overwork, menstruation, seasonal changes, mental stress, etc."

In addition, in this specification, "for the improvement and/or prevention of sensitive skin" refers to the improvement of skin quality with reduced resistance to external stimuli (reduced skin irritation threshold) and/or the prevention of reduced resistance to external stimuli in skin quality (reduced skin irritation threshold).

In addition, the desmoglein-reducing agent of the present invention is preferably used for inhibiting intercellular adhesion of human epidermal keratinocytes.
In this specification, the term "intercellular adhesion" refers to abnormalities in the adhesive function of the stratum corneum (progression of stratification of the stratum corneum due to increased cell adhesiveness) caused by an increase in desmosomal proteins (a group of proteins including desmoglein) (see Patent Nos. 4,197,194 and 4,002,635 for details).
In addition, in this specification, the concept of "inhibiting intercellular adhesion" includes both prevention and improvement of intercellular adhesion.

Here, by inhibiting intercellular adhesion of human epidermal keratinocytes, stratification of the stratum corneum is inhibited, and an effect of inhibiting stratum corneum desquamation can be obtained.
In other words, the desmoglein-reducing agent of the present invention can be used to prevent or improve stratum corneum desquamation.
In this specification, "stratum corneum delamination" refers to the peeling off of the stratum corneum from the skin surface in a multi-layered state. Whether or not the skin is in a state where stratum corneum delamination can be confirmed by collecting the stratum corneum by tape stripping and staining and observing the collected stratum corneum.

Furthermore, areas of the skin with low brightness have a large amount of desmoglein 1. Here, the decrease in skin brightness is thought to be due to stratification of the stratum corneum.
In view of the above findings, the active ingredient of the present invention can reduce desmoglein, thereby improving skin brightness.
That is, the active ingredient of the present invention can also be used as a skin lightening agent.
In this specification, "improving skin brightness" refers to reducing the difference in brightness between normal skin and skin whose brightness has been reduced due to the excess of desmoglein.

In addition, the desmoglein reducing agent of the present invention can provide a more transparent skin condition. In other words, the active ingredient of the present invention can also be used as an agent for improving skin transparency.

Furthermore, areas of high skin hardness contain a large amount of desmoglein 1. Here, it is believed that the cause of skin hardness is the stratification of the stratum corneum.
Based on the above findings, reducing desmoglein makes the skin softer.
In other words, the active ingredient of the present invention can reduce desmoglein, thereby softening the skin, and therefore the active ingredient of the present invention can also be used as a skin softener.

Here, by softening the skin, other medicinal ingredients can penetrate more efficiently, and therefore by reducing desmoglein with the active ingredient of the present invention, it is possible to obtain the effect of allowing medicinal ingredients such as whitening agents to penetrate the skin more efficiently.
That is, the active ingredient of the present invention can also be used as an agent for aiding the penetration of medicinal ingredients into the skin.

In particular, the active ingredient of the present invention is preferably used as a whitening ingredient penetration aid for use in combination with a whitening agent.

(3) Composition The present invention also relates to a composition containing the above-mentioned desmoglein-reducing agent.
In particular, the desmoglein-reducing agent of the present invention is preferably in the form of a composition for external use on the skin or a composition for oral administration.

Suitable examples of skin topical compositions include cosmetics and pharmaceuticals.

In particular, it is preferable for the product to be in the form of a cosmetic product that can be used continuously, such as a lotion, milky lotion, serum, cream, gel, sun care product, etc.

When the composition is prepared as an oral composition, it is preferable to prepare a food composition containing the active ingredient of the present invention.
Specifically, the composition may be in the form of a supplement having the dosage form of a general food, tablet, granule, drink, or the like.

<Preparation of fatty acid-containing PBS>
The fatty acids shown in Table 1 were selected as test samples.

Using an electronic balance, each fatty acid was dispensed into an Eppendorf tube, and methanol was added to adjust the concentration of each fatty acid to 2 μg/μL. Next, 12 mL of PBS was dispensed into a 50 mL tube, 60 μL of each fatty acid was added, and the mixture was vortexed to prepare a fatty acid-containing PBS.
As a control, 12 mL of PBS was dispensed into a 50 mL tube, 60 μL of methanol was added, and the tube was vortexed to prepare a control.

<Preparation process of stratum corneum cell samples>
The third layer of the stratum corneum was collected from the outer side of the human forearm by tape stripping, and the cellophane tape with the stratum corneum attached was cut off and attached to a glass slide. The glass slide was immersed in xylene overnight, then immersed in xylene for 10 minutes twice, and air-dried until no water droplets remained on the glass slide.

<Immunostaining test>
After air drying, the slide glass was immersed in PBS containing a fatty acid sample or a control for 24 hours. After 24 hours, the slide glass was rinsed with PBS and immersed in 4% PFA for 15 minutes to fix the keratinocytes.
The slide glass was then rinsed with PBS and immersed in 0.5% Triton X/PBS at room temperature for 5 minutes for permeabilization. After rinsing with PBS, blocking was performed with 20% Block Ace (KAC) at room temperature for 1 hour. After that, reaction with a primary antibody (anti-Desmoglein 1 mouse monoclonal, DSG1-P23; PROGEN Biotechnik GmbH) was performed at room temperature for 2 hours.

After immersion in PBS for 5 minutes three times, the sample was reacted with a secondary antibody (Goat anti-Mouse IgG (H+L) Cross-Adsorbed Secondary Antibody, Alexa Fluor 488; Invitrogen) at room temperature for 1 hour in the dark. After immersion in PBS for 5 minutes three times, the sample was rinsed twice with distilled water and then mounted.

After that, an all-in-one fluorescence microscope BZ-X800 (KEYENCE) was used to take analytical images of each sample. Three randomly selected locations were cut out from the analytical images, and the cut-out images were binarized. The area (%) of the white portion (stained desmoglein 1) was calculated, with the area of the entire binarized image taken as 100%, and the average value was calculated. The results are shown in Figures 1 to 3.

As shown in Figures 1 to 3, a significant decrease in the amount of desmoglein 1 was observed in six components, namely, methyl linoleate, methyl ricinoleate, ricinoleic acid, linolenic acid, methoprene, and stearic acid.
In particular, the four components methyl linoleate, methyl ricinoleate, ricinoleic acid, and stearic acid were found to have a significant effect of reducing the amount of desmoglein 1.

These results show that the compounds represented by the above general formulas (1) to (4) have the effect of reducing desmoglein.

The present invention can be applied to cosmetics and pharmaceuticals that improve various skin conditions.

Claims (11)

A desmoglein reducer comprising one or more active ingredients selected from the group consisting of methyl linoleate, ricinoleic acid, methyl ricinoleate, linolenic acid and methoprene . The desmoglein-reducing agent according to claim 1 for inhibiting intercellular adhesion of human epidermal keratinocytes. The desmoglein reducing agent according to claim 1 for improving and/or preventing sensitive skin. The desmoglein reducing agent according to claim 1 for improving skin brightness. The desmoglein reducing agent according to claim 1 for improving skin transparency. The desmoglein reducing agent according to claim 1 for softening the skin. The desmoglein reducing agent according to claim 1 for aiding the penetration of medicinal ingredients into the skin. The desmoglein-reducing agent according to claim 1 for improving and/or preventing stratum corneum desquamation. The desmoglein reducing agent according to any one of claims 1 to 8 , wherein the target for reduction is desmoglein 1. A composition for reducing desmoglein, comprising the desmoglein reducing agent according to any one of claims 1 to 9 . The composition according to claim 10 , which is a cosmetic or pharmaceutical product.