JP2011101663A - Method of evaluating wrinkleability - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of appropriately evaluating skin's wrinkleability by clarifying the relation between an oxidized protein in keratin and wrinkleability, forcibly increasing the oxidized protein in the keratin which normally increases with aging, forcibly reproducing wrinkles in an applicable region, and measuring a resultant change in the shape of the skin. <P>SOLUTION: The method of evaluating wrinkleability includes the application of an oxidizing agent to a prescribed region of the skin of a subject, the subsequent forcible formation of wrinkles by compressing and/or bending the surface of the skin including the region to which the oxidizing agent is applied, and the measurement of the depth of the formed wrinkles. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for evaluating the ease with which wrinkles are formed in the skin. More particularly, the present invention relates to a method for evaluating the ease of forming wrinkles using parameters obtained by measuring wrinkles formed by compressing and / or bending skin.

  Wrinkles, which are seen as macroscopic changes in skin, are one of the most prominent changes in the appearance of skin aging, appearing on the face, neck, and other parts of the body such as around the eyes, forehead, and mouth, There is a tendency to increase and deepen with age, which is a major cosmetic concern (Non-Patent Document 1).

  Straight wrinkles (linear wrinkles) that form the corners of the eyes and forehead, and wrinkles that form triangles and quadrilaterals with intersecting grooves found on the cheeks and nape (graphic wrinkles) are repeatedly skinned by the movement of muscles including changes in facial expressions It is believed that deformation will be added to and gradually fixed as wrinkles. It is thought that changes in the structure, function, and physical properties of the skin caused by effects such as aging, oxidation, and sunlight (ultraviolet rays) are deeply involved in the process.

  Many drugs, quasi-drugs, and cosmetics that have an effect of improving wrinkles (anti-wrinkle agents) have been proposed. In order to evaluate their effectiveness, anti-wrinkle agents are applied. It is necessary to evaluate the state of wrinkles before and after. For example, in Patent Document 1, the barrier function of the stratum corneum is lowered by tape stripping the skin or treating with soap or a detergent, and the effectiveness of the anti-wrinkle action is applied by applying a candidate substance to the relevant part. A method of evaluation is described.

  On the other hand, recent studies suggest that protein oxidation in the stratum corneum of the skin is related to aging of the skin due to aging and photoaging due to ultraviolet irradiation, and the oxidized protein in the stratum corneum (hereinafter “ It has been shown that "oxidized protein") can serve as an index for evaluating skin transparency, water retention, flexibility and elasticity (Patent Documents 2 and 3). However, the relationship between oxidized protein in the stratum corneum and wrinkle formation has not yet been elucidated.

JP 2007-68832 A JP-A-2005-249672 JP 2006-349372 A

"New Cosmetics" 2nd edition, Takeo Mitsui, 2001, 45-47, Nanzan-do

  Therefore, the problem in the present invention is to elucidate the relationship between oxidized protein in the stratum corneum and wrinkle formation, and forcibly increase the oxidized protein in the stratum corneum, which usually increases with aging, It is an object of the present invention to provide a method capable of appropriately evaluating the ease of skin wrinkle formation by forcibly reproducing wrinkles and measuring the resulting change in skin shape.

  The present inventors have confirmed a phenomenon in which wrinkles are easily formed and wrinkles are easily fixed when the stratum corneum oxidized protein is artificially increased by subjecting the skin to an oxidation treatment. Then, by measuring the shape of wrinkles that are forcibly formed by compressing and / or bending the oxidized skin, it was found that it is possible to evaluate the tendency to wrinkle, and the present invention was completed. It came to do.

  That is, the present invention applies an oxidizing agent to a predetermined part of the skin, and then compresses and / or bends the skin including the part to which the oxidizing agent is applied to form wrinkles, and measures the shape of the formed wrinkles. A method for evaluating the ease of forming wrinkles is provided according to the parameters obtained by the above.

  According to the method of the present invention, for example, the formation of future wrinkles in the person by forming wrinkles by compression and / or bending in the oxidized and non-oxidized skin of the same person and measuring the formed wrinkle shape. Since it is possible to evaluate ease of use, for example, valuable information for implementing a counseling service in sales of cosmetics and the like can be obtained. Furthermore, the effectiveness of the anti-wrinkle agent can be evaluated by performing the method of the present invention on the skin to which the anti-wrinkle agent is applied.

In the evaluation method of this invention, it is a schematic diagram explaining the process of (a) forming a wrinkle by compression, and (b) forming a wrinkle by bending. In Example 1, it is a graph which shows the change of the parameter (Ra and Rmax) which shows the skin surface shape before and after wrinkle formation by compression. In Example 1, it is a photograph which shows the shape of the skin surface before and behind wrinkle formation by compression. In Example 1, it is a graph which shows the change of the parameters (Ra and Rmax) which show the skin surface shape before and after wrinkle formation by bending. In Example 1, it is a photograph which shows the shape of the skin surface before and behind wrinkle formation by bending. In Example 1, it is a graph which shows the oxidation protein amount in a skin with and without an oxidation process, a change of a softness | flexibility, and elasticity.

Below, the evaluation method of this invention is demonstrated in detail.
In the present invention, first, an oxidizing agent is applied to a predetermined part of the skin to oxidize, thereby increasing the stratum corneum oxidized protein. The oxidizing agent used in the present invention may be known to those skilled in the art, for example, sodium hypochlorite; unsaturated fatty acids such as linoleic acid, oleic acid, palmitoleic acid, squalene, or peroxides thereof; Examples include aldehydes such as acrolein.

  The oxidizing agent of the present invention may be applied to a predetermined site on the skin, for example, in the form of a patch impregnated with the oxidizing agent as described above, or may be applied directly to a predetermined site on the skin. However, it is preferably applied in the form of an oxidant patch in order to allow the oxidant to act on the skin for a predetermined time.

Although the oxidizing agent patch used in the present invention is not particularly limited, for example, a patch of about 1 inch in diameter impregnated with an aqueous sodium hypochlorite solution is preferably used.
In the present invention, the time for applying the oxidizing agent (the “predetermined time”) is not particularly limited as long as it is sufficient for oxidizing the stratum corneum protein, and may be continuous or intermittent.
For example, the oxidation treatment of the present invention can be suitably carried out by repeating the operation of washing the skin after applying an oxidant patch to a predetermined part of the skin washed for about 10 minutes each day for 2 days.

  In the method of the present invention, wrinkles are then forcedly formed on the skin containing the oxidized site. As a method of forming wrinkles, there are a method of forming wrinkles by compressing the skin and a method of forming wrinkles by fixing the skin for a predetermined time in a bent state.

An example of a method for compressing the skin to form wrinkles will be described with reference to the drawings.
First, as shown in FIG. 1A, two flat plates (1, 2) are arranged so as to sandwich an oxidation site (10) in an oxidant patch. In the example of FIG. 1, the flat plates (1, 2) are connected to each other by support members (3, 4) that are movably provided so that they can be translated without being displaced in the lateral direction.
With the two flat plates (1, 2) pressed against the skin, the skin sandwiched between the flat plates (1, 2) is wrinkled by translating one or both flat plates toward each other. .

Next, in a state in which wrinkles are formed by compression (the state on the right side in FIG. 1A), a replica of the skin surface shape of the portion surrounded by the flat plates (1, 2) and the support materials (3, 4) is obtained. Collect and measure the wrinkle shape using the replica.
The measurement of wrinkle shape using a replica is, for example, a method described in “Cosmetics Function Evaluation Method Guidelines” (Japan Cosmetics Society Journal, Vol. 30, No. 4, Supplement, 2006, pp. 316 to 332). However, from the viewpoint of simplicity, it is preferable to employ measurement of the ISO standard surface roughness parameter. In the present invention, Ra (average depth) and Rmax (maximum depth) values obtained by the measurement are employed as parameters representing the degree of wrinkles.
Wrinkle formation by this compression can be assumed to be a reproduction of wrinkles that are temporarily formed by changes in facial expressions on the face.

Next, an example of a method for forming wrinkles by bending the skin will be described.
As shown in FIG.1 (b), the adhesive tape 21 is affixed and fixed in the state which pinched the skin which pinches | interposes an oxidation site | part (10) from both sides, and was bent (folded). After elapse of a predetermined time (for example, 1 hour) in a fixed state, the tape is peeled off, and a replica of the skin surface shape of the bent portion is collected and measured in the same manner as described above to obtain parameters Ra and Rmax.
This wrinkle formation by bending can be assumed to be a reproduction of a fixed wrinkle that has been fixed by repeating temporary wrinkle formation.

  In the evaluation method of the present invention, wrinkle formation by compression and / or bending as described above is performed even on non-oxidized skin of the same subject, and the degree of wrinkles formed is measured and obtained with oxidized skin. Preferably, the method further comprises comparing the obtained parameters (Ra and Rmax) with the parameters (Ra and Rmax) obtained in the non-oxidized skin.

  If there is a significant difference in parameters due to the presence or absence of oxidation, the subject's skin may be considered to tend to form wrinkles due to changes in the skin due to aging or the like (including an increase in oxidized protein). it can. If the site or shape where wrinkles are likely to appear in the future can be estimated, the subject can be careful to protect the site from external stimuli including, for example, sunlight (ultraviolet rays). It is also possible to use it for preventing wrinkles without using such as.

  In addition, the evaluation method of the present invention may include applying a candidate substance that can be an anti-wrinkle agent before or after the application of the oxidizing agent. It is possible to evaluate the effectiveness of the used candidate substance as an anti-wrinkle agent based on the increase / decrease in parameters obtained depending on the presence / absence of the candidate substance.

  The evaluation method of the present invention can be carried out at any part of human skin, but considering simplicity, it is preferably carried out, for example, on the skin inside the forearm. In addition, in the method of comparing the case of oxidation and the case of non-oxidation, for example, a method using an oxidant is performed on the right arm, and a method (control) is performed without using an oxidant on the corresponding part of the left arm. can do.

Example 1
For 10 subjects extracted at random, after washing the skin inside the forearm of both arms, the amount of oxidized protein, moisture, moisture transpiration (TEWL) on the skin surface (horny layer), and cutometer Was used to measure viscoelasticity (hereinafter collectively referred to as “instrument measurement”).
Next, an oxidant patch (a sodium hypochlorite aqueous solution impregnated patch) having a diameter of 1 inch was applied to the corresponding part of one arm, and the patch was peeled off after 10 minutes and washed (day 0). On the next day, the same treatment as the day 0 (cleaning, instrument measurement, oxidant sticking and peeling, cleaning) was performed on the subject (day 1).

  Further, on the next day (day 2), after measuring the same instrument as day 0, a compression wrinkle is formed using an instrument as shown in FIG. 1 (a), the surface shape of the skin is measured, and parameters (Ra and Rmax). Subsequently, the skin of the same site is bent as shown in FIG. 1B and held for 1 hour while being fixed with the tape, and the skin surface shape immediately after the tape is peeled is measured to determine the parameters (Ra and Rmax). Got.

  As shown in FIG. 6, the amount of oxidized protein is increased in the skin to which the oxidant patch is applied, and the softness and elasticity of the skin are decreased as compared with the non-oxidized skin (control). It was.

  The result of the wrinkle formation by compression in the method of the present invention is shown in FIG. Oxidized skin increased both the mean depth (Ra) and maximum depth (Rmax) of wrinkles formed by compression compared to non-oxidized skin (control). FIG. 3 is a photograph showing the appearance of those skins. Obvious wrinkles are clearly formed on the oxidized skin.

  Further, FIG. 4 shows the result of the formation of wrinkles by bending. Similar to the case of compression, in the oxidized skin, both the average depth (Ra) and the maximum depth (Rmax) of wrinkles formed and fixed by bending increased compared to the non-oxidized skin (control). FIG. 5 is a photograph showing the appearance of those skins. Wrinkles are formed on the oxidized skin.

  From the above results, it was clarified that when the skin surface (horny layer) is oxidized, transient wrinkles are easily formed, and the formed wrinkles are easily fixed and fixed.

  According to the evaluation method of the present invention, it is possible to measure the ease of change of the skin surface shape due to the presence or absence of oxidation and the ease of fixing. Therefore, the method of the present invention can also be used to estimate the portion where fixing wrinkles are likely to appear in the future and the degree of fixing wrinkles. Therefore, it can be used to acquire basic information for beauty processing suitable for each individual. Furthermore, if the method of this invention is used, it can also be used for evaluation of the anti-wrinkle agent for improving the wrinkle which may arise in the future appropriately. Moreover, it can be used also for the effectiveness evaluation of the anti-wrinkle effect of the said chemical | medical agent by adding the process of applying the candidate chemical | medical agent used as an anti-wrinkle agent.

1, 2: flat plate, 3, 4: support material, 10: oxidation site, 20: adhesive tape

Claims (7)

The wrinkle depth is formed by applying an oxidant to a predetermined part of the subject's skin and then forcibly forming wrinkles by compressing and / or bending the skin surface including the oxidant application part. A method for evaluating the ease of forming wrinkles, characterized in that The wrinkle formation by the compression is performed by translating one or both of the flat plates in a direction approaching each other while pressing two flat plates arranged in parallel so as to sandwich the oxidant application site. The method according to claim 1. The wrinkle formation by the bending is performed by pinching and fixing the skin including the oxidant application site in a folded state, and releasing the folding after a predetermined time has elapsed. Method. The method according to any one of claims 1 to 3, wherein the application of the oxidizing agent is performed by applying a patch impregnated with the oxidizing agent to the skin. The method of claim 4, wherein the oxidant is hypochlorous acid. Forcibly forming wrinkles by compressing and / or bending the skin surface of the same subject's skin, and measuring the depth of the formed wrinkles 6. A method according to any one of claims 1 to 5, characterized in that it comprises. The anti-wrinkle agent further includes applying an anti-wrinkle agent to the site where the wrinkle is formed, and the wrinkle depth formed when the anti-wrinkle agent is applied is smaller than the wrinkle depth when not applied. The method according to any one of claims 1 to 6, characterized in that is valid.