JPS63253013A - Melanization inhibitor - Google Patents

Abstract

PURPOSE:To obtain a melanization inhibitor, having both melanization inhibitory action and decoloring and reducing action of the formed melanin pigment, by blending bicalein or/and bicalin or a contained extract thereof. CONSTITUTION:A melanization inhibitor, obtained by blending bicalein expressed by formula I and/or bicalein expressed by formula II or bicalein-containing extract and/or bicalin-containing extract in an extract obtained from Scutellariae Radix (root of Scutellaria baicalensis Georg.) as an essential ingredient, capable of providing removing or preventing effects on liver spot of the skin by blending in a recipe of a coating agent for external use, e.g. cosmetic or quasi-drug, since the extract has action of both inhibiting activation of tyrosinase to prevent formation of colored melanin and simultaneously reducing the formed colored melanin pigment or a precursor thereof to provide a colorless substance.

Description

[Detailed description of the invention] [B] Purpose of the invention The present invention relates to a melanin production inhibitor.

(Industrial Field of Application) The present invention can be incorporated into the formulation of external application materials such as cosmetics, pharmaceuticals, and quasi-drugs to obtain stain removal or stain prevention effects on the skin.

(Prior Art) Known examples of melanin production inhibitors include SH group preparations such as cysteine and glutathione, ascorbic acid, and placenta extract.

The main substance used in the present invention is baicalein or baicalin. These substances are known to be contained in the fruit of jujube and Scutellaria.

Scutellaria root It is one of the herbal medicines called ``scutellariae'' in Chinese medicine or diurnal medicine. Research on the application of baicalein, baicalin, or IL extracts from Scutellariae has been conducted for a long time.

When we researched technical literature regarding its use in topical preparations, we found some publications, for example, as shown in the following table (Table 1). Items marked with an asterisk (*) in Table 1 are inventions of the present inventors.

Table 1 Publications related to Scutellariae (problems to be solved by the invention) As melanin production inhibitors, drugs that are mainly applied externally and used in skin (skin) cosmetics include 1, for example:
Applications of thiol compounds such as glutathione and cysteine are known. However, it has a strong off-odor and is easily oxidized, causing problems in formulating it into cosmetics. Ascorbic acid and its derivatives have also been used, but they have the disadvantage of being unstable in aqueous solutions.

On the other hand, when we investigate the publications related to Scutellariae, which is the starting material of the present invention, we find that there are some examples:
No. 04 and JP-A-61-122209 disclose that the extract has moisturizing and stain-preventing effects, and its use as a cosmetic.

Furthermore, although JP-A-62-1006 discloses a whitening effect, it does not disclose what ingredients are used, and it has been completely unknown until now.

On the other hand, the present inventors have already published Japanese Patent Application Laid-Open No. 61-50918.
No., JP-A-61-50921, JP-A-61-1705
No. 51, we have conducted research on the applications of baicalein or baicalin.

As a result of further research, we discovered that baicalein and baicalin are the main substances that inhibit melanin production, and also found that they have a reductive depigmenting effect on the melanin pigment produced. It was.

Namely, the substance according to the present invention is known as one of the biochemical melanin production mechanisms. It was discovered that by suppressing the activation of tyrosinase, it has the effect of both preventing the production of colored melanin and making the colored melanin that has already formed colorless.

[mouth] Structure of the invention (1) Baicalein or baicalin alone (2)
A combination of baicalein and baicalin, (3) a picalein-containing extract, or a baicalin-containing extract alone, (
4) A melanin production inhibitor characterized by the combination of a baicalein-containing extract and a baicalin-containing extract, and the combination of any one of the above (1) to (4).

Specifically, the details will be described below with experimental examples and the like.

Experimental Example 1 A method was adopted in which a specimen or standard solution was added to tyrosine in a constant temperature bath at 37°C, and -tyrosinase was allowed to act for 20 minutes, and the dopachrome produced was measured using an absorbance meter at 475 nm.

The reaction composition is as shown in the first order.

(Reaction composition) L-tyrosine (0.3mg/ml) -==4.0
ml Pine pine buff y - (p[,5)・1.
0m1a semi-liquid or sample・・・・・・・・・・・・・・・
......L, Gml tyrosinase (2500
units/ml) ...0.1 ml (sample used in the experiment) Baicalein (manufactured by Maru Falcos) Specimen A in Table 2 is 70% containing 0.3% baicalein.
A mixed solution of ethanol solution and 1,3-butylene glycol was prepared.

Sample B was a mixture of sample A and purified water.

Sample C was a mixture of sample A and purified water.

Standard solution A was a mixture of 70% ethanol solution and 1.3-butylene glycol.

Standard solution B was a mixture of standard solution A and purified water.

Table 2: Standard solution C is a mixture of standard solution A and purified water.
Tyrosinase activity inhibition effect "Experimental Example 2" This is carried out in the same manner as in Experimental Example 1 above.

As the specimen in Table 3, extract containing 50% icarein (ethanol = 1.3-butylene glycol: water =
5H3Nia mixed solution).

The standard solution is ethanol = 1.3-butylene glycol
:Water==5:3:'l.

Table 3 Tyrosinase activity inhibition effect [Experimental example 3J This is carried out in the same manner as in Experimental Example 1 above.

(Reaction composition) L-tyrosine (0,3Il1g/ml)...
・・・-・1.0ml Matsukurupine Bakfur (PH
6,5)・1.0wl standard solution or sample ・・・・・・・・・
・・・・・・・・・・・・・・・0.5ml tyrosinase (2500 units/ml) ・・・・・・=0.2m
l As the sample in Table 4, baicalein was mixed with methanol 4
It was used after being dissolved in ≠.

The standard solution was a methanol solution.

Table 4 Tyrosinase activity inhibitory effect Looking at the results of the tyrosinase activity inhibitory effect in Experimental Examples 1 to 3, it is found that if the amount of tyrosinase is approximately 0.5 mg, the inhibition rate is As a result, the value was approximately 70%.

r Experiment N4J In a constant temperature bath at 37°C, add 20% of tyrosine and tyrosinase.
Dopachrome is produced by allowing it to act for minutes.

Therefore, the sample or standard solution was added as a first step, and after 1 minute, 475
A method of measurement using a nm absorbance meter was adopted.

(Reaction composition) L-Tyrodi: / (0.3tH/wrl) ・・・・・
・・・・・・・A, 0taL pine pine buffer (pi(G, S) ・1.01al standard solution or sample ・・・・・・・・・・・・・・・・・・・・・1 .0
ml tyrosinase (2500unHs/ml) ==・
...O, 1ml As the sample in Table 5, baikasiin 5
The extract containing 0% was dissolved in (ethanol = 1,3-butylene glycol: water = 5:3 mixed solution).

The standard solution was a mixture of ethanol:1,3-butylene glycol:water=5:3.

Table 5 Reductive decolorization effect [Experiment example 5] It is carried out in the same manner as in Experimental Example 4 described above.

In addition, sample A in Table 6 was prepared by dissolving baicalein in methanol.

Specimen B was an extract containing 4250% Baikasi dissolved in methanol.

Standard solution A was a methanol solution.

Standard solution B was a methanol solution.

Table 6 Reductive Decolorization Effect The reductive decolorization effect in Experimental Examples 4 to 5 is the reaction of tyrosine to melanin polymer, which is produced by dopachrome (which exhibits a red to brown color), and then this dopachrome is reduced. The decolorization ratio was determined.

Although the reduction decolorization rate is not that high,
It was found that Doperchrome decolorizes the melanin polymer even when it has further progressed to become the melanin polymer.

"Experimental Example 6" In a constant temperature bath at 37°C, add tyrosine to tyrosinase.
By reacting for 10 hours or more, a melanin precipitate is generated. However, in this reaction composition,
When baicalein is added.

It was confirmed that no precipitate (melanin polymer) was generated. Figure 1 shows the poor condition of both solutions put into a beaker containing 1 Om 1 container.

This can be confirmed directly with the naked eye. Incidentally, the reaction composition is as shown in the first order.

L-tyrosine (0.3mg/ml) ・−・−・−=
-・1. onl pine curpine buffer (PH6,
5)・1. O+al sample or standard solution (methanol solution)...0.5 intestine 1 was used.

"Experiment Example 7" A healthy boy was selected as the subject, and a large thick black cloth was placed on the left and right sides of the skin on his back. Install two holes and cover them in advance.

Next, ultraviolet light (Toshiba fluorescent lamp: FL-20SE
and FL-20BLB) were connected in parallel with three lights each, and irradiated from a distance of about 15 cm from the back skin for a certain period of time to see the effect of application.

In other words, it is a step of artificially forming darkening.

Changes in skin tone due to the transfer of melanin pigment produced by melanocytes in the basal layer of the skin to the epidermal layer, which creates erythema, can be observed by visual observation and skin color in non-irradiated areas. A method of comparison and evaluation was adopted.

The application sample used was one containing 0.3% of baicalein (-Maru Falcos 1) in accordance with the prescription for parent tree ointment stipulated in the Japanese Pharmacy Law.It was applied 2 to 3 times a day. The time of day was not specified, and the application was carried out continuously for 40 days, with the essential conditions being generally in the morning and in the evening.

The ointment containing baicalein was applied to the left side of the back irradiation site, and the ointment without additives was applied to the right side.

As shown in Table 7 of the results, it can be seen that the formation of darkening on the skin is suppressed.

In addition, the wavelength range of ultraviolet rays! From the light source used, 270-32
0 nm, and between 320 and 400 nm.

In other words, for the erythema that forms after UV irradiation,
Table 7 shows how the blackening (black melanin pigment) on the left and right sides of the back can be suppressed by continuing to apply the ointment immediately, in comparison with the additive-free ointment.

Table 7 Skin black melanin pigment production inhibitory effect In the above experimental examples 1 to 7, baicalein was used.
Icarin, which has sugars bound to it, also exhibits a similar effect, and extracts containing high amounts of icarein and baicalin also exhibit similar effects.

However, with baicalin! Gourd Its action is slower than that of baicalein. In other words, it is unique in that it only exerts its effect on suppressing melanin production after the sugar is cleaved into aglycone. Therefore, to obtain rapid action, baicalein is advantageous, and to obtain slow action, use its aglycone baicalin, and to retain both functions.

The sugar bound to baicalein, which is best used in combination, is cleaved by glucuronidase in the body, heat treatment, etc., or the reaction progresses to baicalin by long-term exposure to harsh ultraviolet rays, etc. ,
Therefore, for example.

Baicalin can also be used in the formulation of cosmetics that undergo heat treatment, such as skin creams and emulsions.

(c) Effects of the Invention The present invention uses baicalein or baicalin as a melanin production inhibitor. Although it is related to a new method of use, it is not necessary to use a pure product, and an extract containing baicalein or baicalin among extracts extracted from Scutellariae may be used.

Next, to explain the mechanism of action of the effects of the present invention, from the biochemical reaction mechanism shown in Figure 2, it is possible to suppress the activation of tyrosinase related to (A) and CB). , at the same time, was generated. Colored Substances (Melanin Precursors) [3] to [5] Furthermore, the colored melanin pigment shown in [6] has both effects as a jA color substance by reducing it.

That is, if we add a new idea to the mechanism of tyrosinase activity inhibition shown in Experimental Examples 1 to 3.

It has an inhibitory effect by binding to the tyrosinase enzyme protein (including competitive inhibition and non-competitive inhibition), and produces chelate compounds with the metals (iron and copper) necessary for the activation of the enzyme, and iron ions and copper necessary for the 1*element reaction. It is thought to have the effect of removing ions and suppressing enzyme reactions (tyrosinase activity suppressing effect).

In addition, the reductive decolorization effect shown in Experimental Examples 4 to 7 is due to the already generated dopachrome (which exhibits a red to brown color).
This is to reduce and decolorize the melanin, and for this reason, the production of *color melanin is suppressed.

Even if the reaction proceeds further than dopachrome and melanin is produced, it exhibits a special reductive decolorizing effect as shown in FIG.

From the results shown in Experimental Examples 1 to 7, the present invention is a melanin production inhibitor that has an inhibitory effect on tyrosinase activity.

As described above, only a very limited number of substances are known that can suppress the stages before and after the production of melanin, dopachrome, dopaquinone, etc., and the present invention is useful for cosmetics, etc. This is considered desirable when using

[Brief explanation of drawings]

Figure 1 shows the state of melanin precipitation, A is the standard solution, B
indicates that colored melanin cannot be observed when baicalein is added. Incidentally, the amount of baicalein shown in B is the state when 0.1 mg was added. Figure 2 shows the chemical reaction mechanism by which melanin is produced. It is a formula. FIG. 4 is the structural formula of baicalein (CI%H1°OS).

Claims (1)

[Scope of Claims] [1] (1) Baicalein or baicalin alone, (2) a combination of baicalein and baicalin, (3) baicalein-containing extract or baicalin-containing extract alone, (4)
A melanin production inhibitor characterized by a combination of a baicalein-containing extract and a baicalin-containing extract, and any one of the components (1) to (4) above.