JPH04282305A - Skin-care cosmetics - Google Patents

Abstract

PURPOSE:To produce the subject skin-care cosmetics capable of preventing dark skin and aging by blending 8-beta-D-glucopyranosyl-7-hydroxy-3-(3',4'- dihydroxyphenyl)-4H-1-benzopyran-4-one, a glucoside obtained from the root of pueraria. CONSTITUTION:A skin-care cosmetics containing 8-beta-D-glucopyranosyl-7- hydroxy-3-(3',4'-dihydroxyphenyl)-4H-1-benzopyran-4-one, excellent in safety to the skin, having effects for preventing melanism of the skin and for rapidly whitening the dark skin and capable of preventing the skin from aging.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention has excellent skin safety, has the effect of preventing skin darkening, the effect of quickly lightening dark skin, and furthermore prevents skin aging. This invention relates to effective skin cosmetics.

0002

[Prior Art and Problems to be Solved by the Invention] Darkening caused by sunburn occurs when tyrosine present in the skin is oxidized and metabolized to melanin. Therefore, preventing this oxidation is important in preventing darkening. It is essential for preventing skin irritation, age spots, and freckles, as well as preventing skin aging.

[0003] As substances having such functions, substances that capture and eliminate active oxygen, substances that inhibit the activity of tyrosinase, an enzyme involved in melanin biosynthesis, and the like are known to be effective.

[0004] JP-A-55-87712 proposes a cosmetic containing superoxide dismutase (SOD) that captures and eliminates active oxygen, but the storage stability of this product is not sufficient. However, it lacked practicality.

[0005] In addition, as a substance having a tyrosinase activity inhibiting effect, a derivative of vitamin C (Japanese Unexamined Patent Publication No. 56-13
5411), hydroquinone derivatives (Japanese Unexamined Patent Publication No. 1983)
-56912)) have been proposed.

[0006] However, these whitening cosmetics either have insufficient storage stability, do not have sufficient whitening effects, or have the effect of lightening dark skin. However, it poses a problem in terms of skin safety, and it has been difficult to obtain a skin-whitening cosmetic that is excellent enough to have a positive whitening effect.

[0007] An object of the present invention is to provide a skin cosmetic that does not cause skin irritation, has the effect of suppressing melanin pigment formation, the effect of quickly lightening dark skin, and has the effect of preventing skin aging. There is a particular thing.

[0008]

[Means for Solving the Problems] The present invention provides 8-β-D-
Glucopyranosyl-7-hydroxy-3-(3',4'
-dihydroxyphenyl)-4H-1-benzopyran-
This skin cosmetic is characterized by containing 4-one (hereinafter abbreviated as PG1).

PG1 used in the skin cosmetic of the present invention is a known glycoside [Planta Medica (Planta Medica)].
medica), p. 250, 1988] and kudzu root by a known method (described in the above-mentioned document).

[0010] The amount of PG1 used in the present invention is preferably 0.0001 based on the total weight of the skin cosmetic composition of the present invention.
~2.0% by weight.

[0011] The skin cosmetic of the present invention had the excellent effect of suppressing the production of melanin and lipid peroxide and preventing pigmentation due to the action of PG1 on the skin.

The skin cosmetics of the present invention can be applied to lotions, milky lotions, creams, packs, etc., for example. In addition to the above, pigments, fragrances, preservatives, surfactants, pigments, and the like may be appropriately incorporated into the skin cosmetic of the present invention within the scope of achieving the object of the present invention.

[0013]

[Examples] The present invention will be explained in detail below based on Examples and Comparative Examples. In addition, ■ skin irritation test described in Examples,
■Active oxygen elimination test, ■Tyrosinase activity inhibition rate measurement test, ■Skin color brightness recovery test, and ■Whitening practical test are shown below.

■Skin irritation test 0.05g of sample was applied to the skin of the flexor side of the forearm of 25 subjects who were exposed to summer sunlight for 6 hours (3 hours a day for 2 days) using a circular linen cloth with a diameter of 1.0cm. After 24 hours of occlusive application using a cloth-attached patch test bandage, each sample was evaluated for the skin condition of 25 subjects according to the criteria in Table 1. The judgment result is based on the stronger reaction between 1 hour and 24 hours after the removal of the bandage, and the evaluation is (±).
It is shown in the number of people above.

[0015]

[Table 1]

■ Active oxygen scavenging test 0.05 mol sodium carbonate solution (pH 10.2) 2
．． 4 ml, 3 mmol xanthine 0.1 ml, 3 mmol ethylenediaminetetraacetate 0.1 ml
, 0.15% calf serum albumin 0.1ml, 0.75
Millimole Nitro Blue Tetrazolium 0.1ml
, add 0.1 ml of the sample solution, and pre-incubate at 25°C for 10 minutes. Add 0.1 ml of 0.17 units/ml xanthine oxidase to this, heat at 25°C for 20 minutes, and then measure the absorbance at a wavelength of 560 nm (T
1) was measured.

On the other hand, the absorbance (T2) when 0.1 ml of water was added instead of xanthine oxidase, and the absorbance (T3) when 0.1 ml of water was added instead of the sample solution.
), the sample solution, and the absorbance (T4) of a solution to which 0.2 ml of water was added instead of xanthine oxidase were measured, and the inhibition rate (%) was calculated using the following formula.

[0018] As a result, evaluation was made according to the following classification.

①Tyrosinase activity inhibition rate measurement test The measurement principle is to measure dobachrome produced by the action of tyrosinase on tyrosine. The reaction composition was 1.0 ml of L-tyrosine (0.3 mg/ml), 1.0 ml of McCleben buffer (pH 6.8), and 0.9 ml of sample solution.
Prepare a total volume of 2.9 ml, incubate at 37°C for 10 minutes, add 0.1 ml of tyrosinase (1 mg/ml, mushroom, manufactured by Sigma),
C. for 15 minutes, and the absorbance at 475 nm was measured. The inactivation of tyrosinase enzyme inhibitory activity was calculated using the following formula.

(A): Addition of buffer solution instead of sample (B): Addition of sample (C): Addition of buffer solution instead of tyrosinase (D):
As a result, adding buffer instead of tyrosinase and sample
Evaluation was made according to the following classification.

■Skin color brightness recovery test The back skin of 20 test subjects was irradiated with ultraviolet rays in the UV-B region twice the minimum amount of erythema, and one week later, the irradiated areas were divided into sample application areas and non-application areas. were set, and the reference brightness (Vo value, Vo' value) of each skin was measured. Subsequently, the sample was continuously applied to the application site once a day for 3 months.
After 13 weeks, skin brightness (V
n... value, Vn'... value) was measured, and skin color recovery evaluation was performed according to the criteria shown in Table 2.

[0022]

[Table 2]

The brightness of the skin (Munsell colorimeter V value) was calculated from the X, Y, and Z values obtained by measurement with a high-speed spectrocolorimeter. Moreover, the evaluation was shown as the average value of the evaluation scores of 20 test subjects after 13 weeks.

■Practical skin whitening test The skin on the flexor side of the forearm of 20 subjects who were exposed to sunlight for 3 hours (1.5 hours a day for 2 days) in the summer was tested. Starting from the day after exposure to sunlight, and 7 days after exposure to sunlight, the samples were applied once in the morning and once in the evening for 13 weeks on the flexor side of the right forearm. The evaluation was expressed by the number of subjects who answered that the skin area to which the sample was applied was fairer (light skin) than other skin areas.

Examples 1 to 4, Comparative Examples 1 to 3 [Skin cream] Skin creams having the compositions shown in Table 3 were prepared and various tests were carried out, and the results are shown in Table 4.

[0026]

[Table 3]

[0027]

[Table 4]

(2) Preparation method Component (B) is uniformly dissolved in component (C) and heated to 80°C. Furthermore, component (A) was heated to 80°C and added to (
C) Inject and stir the ingredients. Next, the mixture is cooled to a temperature of 30° C. while stirring.

(3) Properties As shown in Table 4, the skin creams of the present invention of Examples 1 to 4 showed good results in all tests.

On the other hand, as is clear from Comparative Examples 1 and 2, PG
Skin cream that does not contain 1 or contains 0.0
Skin creams containing less than 0.001 wt% were inferior in various properties. Further, as is clear from Comparative Example 3, the skin cream containing arbutin, a hydroquinone derivative, was also inferior in various properties.

[0031]

As described above, the present invention provides a useful skin cosmetic that does not cause skin irritation, has an excellent effect of suppressing melanin pigment formation, quickly lightens dark skin, and prevents aging. It is clear that they will provide a fee.

Claims (1)

[Claims] [Claim 1] 8-β-D-glucopyranosyl-7-
A skin cosmetic comprising hydroxy-3-(3',4'-dihydroxyphenyl)-4H-1-benzopyran-4-one.