JP7504346B2 - Skin Composition - Google Patents

Description

The present invention relates to a skin composition that has wrinkle improving and whitening effects.

Shinorine is a type of mycosporine-like amino acids (MAAs), a group of rare natural amino acids, and is known to be one of the naturally occurring substances with the highest ultraviolet absorbing capacity. It has particularly high absorption capacity in the UVA region, which is the cause of skin aging such as spots, wrinkles, and sagging. It has a maximum absorption in the UV-A2 region (320-340 nm), a region that cannot be fully covered by existing ultraviolet absorbents. In nature, shinorine is found in aquatic organisms such as red algae, coral, and cyanobacteria.

Shinorine is a water-soluble substance, which has great merit when formulated into quasi-drugs and cosmetics. MAAs containing shinorine work to reduce damage to elastin and collagen in the skin caused by ultraviolet rays. It has also been suggested to promote the production of hyaluronic acid, making it a promising substance with strong anti-aging effects.

It is known that shinorine is used as a quasi-drug or cosmetic ingredient (Patent Document 1). A method for producing shinorine is also known (Patent Document 2).

JP 2018-52883 A Patent No. 5927593 Publication

The object of the present invention is to provide a skin composition that has excellent wrinkle improving and whitening effects.

As a result of extensive research, the inventors of the present invention discovered that the coexistence of microsporin-like amino acids and antioxidants provides excellent wrinkle-improving and whitening effects, and thus completed the present invention.

That is, the present invention provides the following.
(1) (i) Shinorine;
(ii) a composition for inhibiting tyrosinase activity , comprising at least one antioxidant selected from the group consisting of kojic acid, hydroquinone, and ascorbic acid.
(2) A tyrosinase activity inhibitory composition according to (1), comprising a seaweed extract containing shinorine.

The present invention provides a skin composition that has excellent wrinkle improving and whitening effects.

The skin composition of the present invention may be a cosmetic product or a quasi-drug product such as a whitening cosmetic product or an anti-wrinkle cosmetic product. Examples of the form of the skin composition include, but are not limited to, a lotion, milky lotion, cream, beauty serum, UV cream, BB cream, makeup base, etc.

The microsporin-like amino acids contained as essential components in the skin composition of the present invention and the method for producing them are known and commercially available, so commercially available products can be used. Examples of microsporin-like amino acids include shinorine, paricine, porphyra 334, mycosporine glycine, and the like. Of these, shinorine is preferred. These microsporin-like amino acids may be contained alone or in combination. In addition, these microsporin-like amino acids are contained in seaweed extracts (green algae extracts, brown algae extracts, red algae extracts), so the seaweed extracts may be included in the composition without purifying each microsporin-like amino acid.

The amount of microsporin-like amino acid in the composition (the total amount when multiple types are included) is not particularly limited and is appropriately set within the range that exhibits wrinkle improvement and whitening effects, but is usually about 0.01 μg to 100 μg, preferably about 0.05 μg to 50 μg, and more preferably about 0.1 μg to 5.0 μg per 1 mL of the total composition.

The antioxidant contained as an essential component in the skin composition of the present invention is not particularly limited as long as it is an antioxidant that can be applied to the skin, and various antioxidants known to be used as components of cosmetics or quasi-drugs can be used. Examples of such antioxidants include, but are not limited to, tranexamic acid, kojic acid, retinol, coenzyme Q10, hydroquinone, tocopherol, ascorbic acid, β-carotene, BHT, sodium sulfite, sodium metabisulfite, and derivatives thereof. Of these, tranexamic acid, kojic acid, retinol, coenzyme Q10, hydroquinone, tocopherol, ascorbic acid, and β-carotene are preferred. The antioxidants can be used alone or in combination of two or more. The amount of antioxidant in the composition (the total amount when two or more antioxidants are used) is not particularly limited and is appropriately set within the range that exhibits wrinkle improvement and whitening effects, but is usually about 0.01 μg to 100 μg mass% per 1 mL of the total composition, preferably about 0.05 μg to 50 μg, and more preferably about 0.1 μg to 10 μg.

A particularly excellent wrinkle-improving effect can be obtained by blending at least one selected from the group consisting of tranexamic acid, kojic acid, retinol, coenzyme Q10, hydroquinone, tocopherol, ascorbic acid, and β-carotene among the above antioxidants. The wrinkle-improving effect can be evaluated by the effect of promoting hyaluronic acid production or the effect of promoting collagen production, as specifically described in the Examples below. Furthermore, a particularly excellent whitening effect can be obtained by blending at least one selected from the group consisting of kojic acid, hydroquinone, ascorbic acid, and tranexamic acid among the above antioxidants. The whitening effect can be evaluated by the effect of inhibiting tyrosinase activity, as specifically described in the Examples below.

The skin composition of the present invention exerts wrinkle-improving and whitening effects, and can therefore be used as a wrinkle-improving agent or whitening cosmetic. Of course, it can also be used as a cosmetic composition that exerts both wrinkle-improving and whitening effects at the same time. In this case, it is preferable to use an antioxidant that is excellent in both wrinkle-improving and whitening effects, that is, at least one selected from the group consisting of kojic acid, hydroquinone, ascorbic acid, and tranexamic acid.

The cosmetic composition of the present invention may contain the above-mentioned components in a solvent, and the solvent is preferably water (a small amount (about 5% by mass or less) of ethanol may be contained). When the solvent is water, the cosmetic composition is in the form of a lotion. In the case of a lotion, the cosmetic composition of the present invention can be produced by adding each component to water and homogenizing it. The cosmetic composition of the present invention is not limited to the form of a lotion, and can also be in the form of a cream or gel by a well-known method. When the cosmetic composition is in the form of a cream, as is well known, it can be made into the form of a cream by adding additives such as glyceryl monostearate, polyethylene glycol monostearate, polysorbate, polyoxyethylene hydrogenated castor oil, polyoxyethylene lauryl ethers, for example, in an amount of about 0.10% by mass to 20.00% by mass. Furthermore, when forming a gel, as is well known, additives such as carboxyvinyl polymers, (acrylates/alkyl acrylate) crosspolymers, polyacrylamide, gelatin, hydroxyethyl cellulose, xanthan gum, sodium dilauroyl glutamate lysine, acrylates crosspolymers, bentonites, hectorites, (acrylates/steareth-20 itaconate) copolymers, hydroxypropyl starch phosphate, sodium polyglutamate, polyvinylpyrrolidone, (vinylpyrrolidone/VA) copolymers, stearoxyhydroxypropylmethylcellulose, polyvinyl alcohol, and tremella fuciformis polysaccharides can be added in an amount of, for example, about 0.01% to 10.00% by mass to form a gel.

The cosmetic composition of the present invention may further contain various additives used in cosmetics in addition to the essential components described above. Examples of such additives include, but are not limited to, antibacterial agents, moisturizing agents, and anti-inflammatory agents. Examples of antibacterial agents include parabens, phenoxyethanol, pentylene glycol, glyceryl caprate, isopropylmethylphenol, O-cymen-5-ol, and octanediol. Examples of moisturizing agents include glycerin, butylene glycol, sodium hyaluronate, ceramides, sodium chondroitin sulfate, collagen, licorice leaf extract, Gynostemma pentaphyllum leaf extract, and Alpinia speciosa leaf extract. Examples of anti-inflammatory agents include dipotassium glycyrrhizinate, allantoin, Scutellaria baicalensis extract, Panax ginseng extract, chamomile extract, and licorice flavonoids.

The present invention will be specifically described below based on examples. However, the present invention is not limited to the following examples.

Examples 1 to 18, Comparative Examples 1 to 19 Hyaluronic acid production promoting effect (wrinkle improvement effect) test Compositions were prepared by dissolving 1 μg of shinorine and various antioxidants shown in Table 1 in the amounts shown in Table 1 in 1 mL of purified water. For comparison, a composition was prepared by dissolving 1 μg of shinorine alone in 1 mL of purified water (Comparative Example 1) and a composition was prepared by dissolving only an antioxidant shown in Table 1 in 1 mL of purified water (Comparative Examples 2 to 19). Purified water was used as a negative control, and N-acetylglucosamine (GlcNac) was used as a positive control.

The hyaluronic acid production promotion effect was evaluated as follows. Human dermal fibroblasts (Kurabo Industries, Ltd.) were placed in each well of a 24-well plate at 5 x 10,000 cells/ml. They were cultured for 72 hours at 37°C in 5% carbon dioxide using 5% FCS-MEM (Fetal Calf Serum-Minimum Essential Amino Acids Media). After that, the medium was replaced with 0.5% FCS-MEM, and the sample was added to a final concentration of 10 μg/ml. N-acetylglucosamine, the positive control, was added to a final concentration of 0.1 mMol. The amount of hyaluronic acid in each culture supernatant 24 hours after addition was quantified. The binding protein sandwich method using hyaluronic acid binding protein (HABP) and biotin-labeled HABP was used. Absorbance was measured at 450 nm using a microplate reader. The hyaluronic acid production promotion rate was calculated by setting the amount of hyaluronic acid in the negative control as 100. The results are shown in Table 2 below.

As shown in Table 1, the amount of hyaluronic acid in each Example was greater than the sum of the amount when only shinorine was included (Comparative Example 1) and the amount when only the corresponding concentration of each antioxidant was included (Comparative Examples 2 to 19). This demonstrates that the combined use of shinorine and various antioxidants produces a synergistic effect on the amount of hyaluronic acid produced.

Examples 19-21, Comparative Examples 20-23 Skin Whitening Effect Test 0.5 μg of shinorine and 0.5 μg of each antioxidant shown in Table 2 below were dissolved in 1 mL of purified water (Examples 19-21). For comparison, 0.5 μg of shinorine was dissolved in 1 mL of purified water (Comparative Example 20). In addition, 0.5 μg of each antioxidant was dissolved in 1 mL of purified water (Comparative Examples 20-23).

In the melanin production process, tyrosinase catalyzes the hydroxylation reaction of tyrosine to L-DOPA and the oxidation reaction of L-DOPA to dopaquinone, and directly affects the biosynthesis of melanin from tyrosine in the body. Inhibition of tyrosinase leads to inhibition of melanin production. The effect of the composition of the present invention in inhibiting tyrosinase activity was investigated.

333 μl of 2.5 mM L-tyrosine aqueous solution was added to 600 μl of 0.1 M phosphate buffer (pH 6.5). Both reagents were incubated at 25°C. Next, 33 μl of sample solution (DMSO solution) was added and stirred, and 33 μl of tyrosinase aqueous solution (1380 units/ml) was added to start the enzyme reaction. A spectrophotometer was used for measurement. The inside of the measuring device was set to be kept at 25°C. Activity was evaluated using the change in absorbance (405 nm) of melanin synthesized by tyrosinase as an indicator. The results are shown in Table 2 below.

As shown in Table 2, the tyrosinase inhibition percentage in each Example was greater than the sum of the percentages when only shinorine was included (Comparative Example 20) and when only the corresponding concentrations of each antioxidant were included (Comparative Examples 21 to 23), demonstrating that the combined use of shinorine with various antioxidants exerts a synergistic effect on the inhibitory activity of tyrosinase.

Examples 23 to 62, Comparative Examples 24 to 64 Collagen Production Promotion Effect (Wrinkle Improvement Effect) Test After normal human fibroblasts were exposed to the test substances for 48 hours, intracellular collagen and non-collagen proteins were stained by a standard method using staining solutions (Sirius Red and Fast Green), and a test was performed to quantify the amount of collagen in the cells.

As a preliminary test, human fibroblasts cultured for 24 hours were exposed to the test substance (1.0 mL) for 48 hours, and the cell viability was determined using the MTT method to confirm the test substance concentration that did not affect the cells. The substances contained in 1.0 mL of the test substance were 50% ethanol, the total amount of the test substance, and the remainder was water.

In this test, human fibroblasts were cultured in a test plate for 24 hours, and the medium was replaced with one mixed with 1.0 mL of the test substance and cultured for 48 hours. The cells were stained with Sirius Red and Fast Green, and collagen and protein were extracted by standard methods. The absorbance (570 nm) was measured to determine the amount of collagen per total protein. There were three samples in each case. 3-O-ethyl ascorbic acid was used as a positive control (data not shown). The results are shown in Table 3 below.

As shown in Table 3, no collagen was produced when shinorine was used alone (1 μg) (Comparative Example 64), whereas when shinorine was used in combination with each antioxidant, the absorbance was greater than when each antioxidant was used alone. Therefore, a synergistic effect was confirmed by using shinorine in combination with each antioxidant.

Claims (2)

(1) Shinorin and
(2) A composition for inhibiting tyrosinase activity , comprising at least one antioxidant selected from the group consisting of kojic acid, hydroquinone, and ascorbic acid. The tyrosinase activity inhibitor composition according to claim 1 , comprising a seaweed extract containing shinorine.