JP5531263B2 - Tyrosinase activity inhibitor and whitening cosmetic containing the same - Google Patents

Description

  The present invention relates to a tyrosinase activity inhibitor, and more particularly to a tyrosinase activity inhibitor that effectively inhibits tyrosinase related to melanin production and a whitening cosmetic using the same.

  Currently, many whitening cosmetics are on the market for the purpose of preventing sunburn, spots, freckles and the like on the skin. These whitening cosmetics contain components that prevent the production of melanin, which is a pigment substance, and many of them are tyrosinase activity inhibitors that inhibit tyrosinase, which is the rate-limiting enzyme for melanin production.

  As typical tyrosinase activity inhibitors, kojic acid, arbutin and the like are known. Of these, kojic acid is produced in the fermentation product of Aspergillus oryzae, and its tyrosinase inhibitory activity is high, but there are reports of carcinogenicity by oral ingestion and side effects such as leukocyte reduction, etc. It is hard to say that is sufficiently secured. Arbutin is a compound that can be obtained from an extract of walnut and bilberry, and its safety has been almost confirmed. However, there is a problem that its tyrosinase inhibitory activity is weaker than that of kojic acid.

Furthermore, although reports on obtaining tyrosinase activity-inhibiting components obtained from plants other than the above have been made (Patent Documents 1 to 6 and the like), there is still a strong demand for providing new tyrosinase activity-inhibiting components. there were.
JP-A-5-294819 JP-A-6-305978 JP 10-114670 A JP 2003-55189 A JP 2006-176420 A JP 2006-69954 A

  An object of the present invention is to provide a novel tyrosinase activity inhibitor having excellent activity and high safety.

  The inventors of the present invention focused on plant resources in Okinawa Prefecture and conducted an extensive search for those having tyrosinase inhibitory activity. As a result, they found that legumes have excellent tyrosinase inhibitory activity and completed the present invention.

  That is, the present invention is a tyrosinase activity inhibitor containing a leguminous plant extract as an active ingredient.

  Moreover, this invention is the skin external preparation and whitening cosmetics containing the said tyrosinase tyrosinase activity inhibitor.

  The extract of legumes which is an active ingredient of the tyrosinase activity inhibitor of the present invention has excellent tyrosinase inhibitory activity and high safety.

  Therefore, the tyrosinase activity inhibitor of the present invention can be used as a whitening component in a skin external preparation, a whitening cosmetic, or the like.

  The active ingredient of the tyrosinase activity inhibitor of the present invention is an extract obtained by subjecting legumes to an extraction treatment. As the legumes, preferably, the mossena (Cassia glauca Lam), medhagi (Lespedeza cuneata (Dum.Cours.) G. Dom), junkeboku (Peltophorum Peltophorum), osmbo butterfly (Caesalpinia pulcherrima Sw), Examples include Lespedeza liukiuensis), Acacia confusa, and Hamasena (Ormocarpum cochinchinense). Examples of the extraction solvent include water and lower alcohols, but a mixed solution of water and lower alcohols is preferable.

  The leguminous plant extraction treatment may be performed, for example, after drying the leaves, flowers, leaf stems or whole grass of legumes, cutting or crushing them, adding 5 to 20 times by weight of the extraction solvent, and adding room temperature It is carried out by dipping at 100 to 100 ° C., preferably 30 to 50 ° C., for 12 to 150 hours, preferably 24 to 48 hours. In this extraction, it is preferable to shake or mechanically stir.

  Subsequently, the extract of legumes can be obtained by clarifying this extract by solid-liquid separation means using industrial filter paper, diatomaceous earth, centrifugal separation, membrane filter or the like.

  This leguminous plant extract can be further purified by using a known purification means, for example, appropriate various column chromatography, ultrafiltration, or the like, if necessary, to obtain a tyrosinase activity inhibitor. Moreover, it can also be set as the tyrosinase activity inhibitor pulverized by the well-known drying means, for example, spray drying, freeze drying, drum drying etc. as needed.

  The tyrosinase activity inhibitor of the present invention obtained as described above can be used by blending with a skin external preparation or a whitening cosmetic composition according to a conventional method.

  For example, in the case of whitening cosmetics, the tyrosinase activity inhibitor is mixed in a known cosmetic base with, for example, about 0.001 to 5% by mass, and a cosmetic liquid, milky lotion, cream, paste is added according to a conventional method. And it is sufficient.

  EXAMPLES Next, although a reference example and an Example are given and this invention is demonstrated in more detail, this invention is not restrict | limited at all by these Examples.

Reference example 1
Acquisition of legume extract:
As leguminous plants, Mokusenna, Medhagi, Junkeiboku, Giant butterfly, Ryukyuhagi, Soshijuju and Hamasena were obtained and subjected to the following extraction operation to obtain a leguminous plant extract as a plant extract.

(Extraction operation)
Each legume was cut into a suitable size for each part, and then each was dried at 60 ° C. for 12 hours, and pulverized using a centrifugal pulverizer (MRK-Retschm, ZM-100). What passed through a 0.5 mm screen was collected, and this was subjected to solvent extraction using a high-speed solvent extraction device (manufactured by Nippon Dionex, ASE-200). That is, each 2 g of sample by dry weight was loaded into an extraction cell together with 8 g of diatomaceous earth, and 50% ethanol solution was used to extract 50 ml in total at an extraction temperature of 80 ° C., an extraction time of 10 minutes, a pressure of 1500 psi, and two extractions. A plant extract was obtained.

Example 1
The plant extract obtained in Reference Example 1 was diluted 10 times with ion-exchanged water (hereinafter referred to as “sample solution”) and subjected to a tyrosinase inhibitory activity test. First, tyrosinase (derived from mushrooms, manufactured by Sigma) was adjusted to 40 U / ml with ion-exchanged water to obtain an enzyme solution. In addition, 3,4-dihydroxy-L-phenylalanine (hereinafter referred to as “DOPA”; manufactured by Sigma) was adjusted to 2.5 mM with ion-exchanged water to obtain a substrate solution. Furthermore, 1 / 15M phosphate buffer (pH 6.8) was used as a buffer solution.

  The enzyme reaction was performed in a 96-well microplate. To each well of the microplate, 100 μl of buffer solution, 40 μl of enzyme solution and 20 μl of sample solution were added, mixed well, and pre-incubated at 23 ° C. for 3 minutes. After pre-incubation, 50 μl of the substrate solution was added, and the absorbance at 490 nm (As0) was immediately measured. The enzyme reaction was performed at 23 ° C. for 10 minutes, and the absorbance (As10) after 10 minutes of the reaction was measured. Furthermore, the reaction was carried out in the same manner in a system in which 20 μl of a 5% ethanol solution was added instead of 20 μl of the sample solution and a system in which 40 μl of a buffer solution was added instead of 40 μl of the enzyme solution, and the absorbance immediately after the start of the reaction and after 10 minutes in each case (Ac0, Ac10 and Ab0, Ab10) were measured. Tyrosinase inhibitory activity was calculated by the following formula.

Tyrosinase inhibition rate (%) = 100 − [[(As10−Ab10) −
(As0−Ab0)] / (Ac10−Ac0) × 100]

Table 1 shows the tyrosinase inhibitory activity in each sample solution. In addition, the sample solution was dried under reduced pressure and re-dissolved in a 5% ethanol solution at a predetermined concentration. The concentration was decreased stepwise and the tyrosinase inhibitory activity test was conducted. The tyrosinase inhibitory activity was reduced to 50%. The concentration of tyrosinase in the sample solution (IC ₅₀ , mg / ml) was determined by interpolation. The results are shown in Table 2.

  As apparent from Tables 1 and 2, the legume extract of the present invention had excellent tyrosinase inhibitory activity.

Example 2
Whitening cosmetics:
A whitening cosmetic was prepared by the following composition and production method. This product had an excellent whitening effect.
(Composition) (mass%)
(1) Mokusenna extract ^* 0.1
(2) Dipropylene glycol 5
(3) PEG400 5
(4) Ethanol 10
(5) Xanthan gum 0.5
(6) POE (6-20) sorbitan monostearic acid 1
Esters (7) Oleyl alcohol 0.5
(8) Ascorbic acid 2
(9) Vitamin E acetate 0.2
(10) Amount of purified water remaining
* Extract of moxenna (flower) from Example 1

(Production method)
(A) (5), (2), (3) and (8) are sequentially dissolved in this order in (10).
(B) (1), (6), (7) and (9) are sequentially dissolved in this order in (4).
(C) The aqueous solution obtained in (a) and the ethanol aqueous solution obtained in (b) are mixed using a vacuum emulsifier, and then filled into a container to obtain an emulsion whitening cosmetic.

  The legume extract of the present invention had excellent tyrosinase inhibitory activity.

  Therefore, the tyrosinase activity inhibitor which uses this leguminous plant extract as an active ingredient can be advantageously used as an active ingredient of a skin external preparation or a whitening cosmetic.

Claims (4)

  A tyrosinase activity inhibitor comprising as an active ingredient a leguminous plant extract selected from the group consisting of Moxena, Medhagi, Junkeiboku, Ogochou, Ryukyuhagi, Soushiju and Hamasenna.   The tyrosinase activity inhibitor according to claim 1, wherein the leguminous plant extract is extracted from a mixture of water and a lower alcohol. A whitening cosmetic comprising a tyrosinase activity inhibitor comprising, as an active ingredient, a leguminous plant extract selected from the group consisting of Medhagi, Junkeiboku, Ogocho butterfly, Ryukyuhagi, Soushiju and Hamasena. The whitening cosmetic composition according to claim 3, wherein the leguminous plant extract is extracted from a mixture of water and a lower alcohol.