Melanin production inhibition device and method for inhibiting melanin production

Abstract

To provide a skin treatment device and a skin treatment method that are suitable for effectively inhibiting melanin production in an irradiated skin part of a human.SOLUTION: A skin treatment device and a skin treatment method include a light source for generating prescribed light having a center wavelength in a wavelength range of longer than 490 nm and 525 nm or shorter and can irradiate a skin with prescribed light from the light source. Prescribed light has preferably a center wavelength of substantially 505 nm.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to an apparatus and a method for inhibiting melanin production. [Background technology]

[0002] 2. Description of the Related Art A skin wound healing device is known that includes an ultra-narrowband light irradiating means that generates ultra-narrowband green light having a peak wavelength range of 500 nm to 540 nm and a half-width of 10 nm or less. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO2011 / 067941 Brochure Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the above-mentioned conventional techniques, it is difficult to effectively suppress melanin production in irradiated human skin areas.

[0005] Therefore, the present disclosure aims to effectively suppress melanin production in irradiated human skin sites. [Means for solving the problem]

[0006] In one aspect, a light source is provided that generates a predetermined light having a center wavelength in a wavelength range longer than 490 nm and not exceeding 525 nm, A skin treatment device is disclosed that is capable of irradiating skin with the predetermined light from the light source. Effect of the Invention

[0007] According to the present disclosure, it is possible to effectively suppress melanin production in irradiated human skin areas. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing the appearance of a light irradiation device according to an embodiment of the present invention; [Diagram 2] 1 is an explanatory diagram of the characteristics of light (predetermined light) emitted from an LED. [Diagram 3] FIG. 2 is a diagram showing an outline of a control system for the light irradiation device. [Figure 3A] FIG. 2 is a diagram illustrating an example of a hardware configuration of a control device. [Figure 4A] FIG. 1 shows test results (part 1) concerning the melanin production suppression effect by irradiation with green LED light. [Figure 4B] FIG. 13 is a diagram showing test results (part 2) concerning the melanin production suppression effect by irradiation with green LED light. [Figure 5A] FIG. 13 is a diagram showing test results (part 3) concerning the melanin production suppression effect by irradiation with green LED light. [Figure 5B] FIG. 13 is a diagram showing test results (part 4) concerning the melanin production suppression effect by irradiation with green LED light. [Figure 5C] FIG. 5 is a diagram showing test results (part 5) concerning the melanin production suppression effect by irradiation with green LED light. [Figure 5D] FIG. 13 is a diagram showing test results (part 6) concerning the melanin production suppression effect by irradiation with green LED light. [Figure 5E] FIG. 5B is a table showing the evaluation results obtained from the test results of FIGS. 5A to 5E. [Figure 6A] FIG. 13 is a diagram showing test results (part 7) concerning the melanin production suppression effect by irradiation with green LED light. [Figure 6B] FIG. 13 is a diagram showing test results (part 8) concerning the melanin production suppression effect by irradiation with green LED light. [Figure 7A] FIG. 9 is a diagram showing test results (part 9) concerning the melanin production suppression effect by irradiation with green LED light. [Figure 7B] FIG. 10 is a diagram showing test results (part 10) concerning the melanin production inhibitory effect of green LED light irradiation. [Figure 8]1 is a table showing the relationship between the radiation intensity of green LED light and its effect (inhibitory effect on melanin production). [Figure 9] This is a graph (part 1) showing the relationship between the radiation intensity of green LED light and its effect. [Figure 10] This is graph (part 2) showing the relationship between the radiation intensity of green LED light and its effect. [Figure 11] This is graph (part 3) showing the relationship between the radiation intensity of green LED light and its effect. [Figure 11A] 13 is a graph showing another test result regarding the relationship between the radiant intensity of green LED light and the effect. [Figure 12] FIG. 1 is a diagram showing test results (part 1) relating to differences in melanin production inhibitory effects caused by differences in wavelength. [Figure 13] FIG. 2 is a diagram showing test results (part 2) relating to differences in melanin production inhibitory effects caused by differences in wavelength. [Figure 14] FIG. 13 is a diagram showing test results (part 3) relating to differences in melanin production inhibitory effects caused by differences in wavelength. [Figure 15] FIG. 1 shows test results regarding the expression level of keratin 10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Each embodiment will be described in detail below with reference to the accompanying drawings.

[0010] FIG. 1 is a perspective view showing a light irradiation device 1 according to the present embodiment.

[0011] The light irradiation device 1 generates light that can be irradiated onto human skin. The light may have a beauty-related effect. In this case, the beauty-related effect is arbitrary and may include hair removal, skin beautification, elimination of sagging, tightening, fat burning, lifting, face slimming, skin firmness, luster, improved moisture, or any combination of one or more of the above. Furthermore, the beauty-related effect may be a quantifiable effect or may not be a quantifiable effect.

[0012] The functions of the light irradiation device 1 can be realized by a single computer in the light irradiation device 1, or by a combination of the computer in the light irradiation device 1 and an external server and / or a user terminal. In this case, a computer-readable program that realizes the functions of the light irradiation device 1 may be executed by the computer in the light irradiation device 1, or may be executed by a combination of the computer in the light irradiation device 1 and an external server and / or a user terminal.

[0013] Although the light irradiation device 1 shown in FIG. 1 is a portable type that can be held by the user's hand, it may be applied to a movable type that is movably supported on a fixed device via an arm or the like.

[0014] The light irradiation device 1 includes a grip portion 2 and a head portion 3. In this case, a user can locally irradiate light from the light irradiation device 1 to a desired portion by holding the grip portion 2 and directing a skin facing portion 3a (described later) of the head portion 3 to the desired portion on the user's face or body.

[0015] The grip part 2 has a shape that is easily held by the user's hand. The grip part 2 may include an input part (not shown) including various buttons such as a power on / off button, a mode switching button, an intensity adjustment button, etc. The various buttons may be mechanical buttons or touch switches. The grip part 2 may also be provided with a display part (not shown) that displays the state of the light irradiation device 1, etc.

[0016] The head portion 3 is provided at the end of the grip portion 2. The head portion 3 may be fixed to the grip portion 2, may be detachable, or may be movable relative to the grip portion 2. In addition, the head portion 3 may be provided with a plurality of detachable attachments.

[0017] The head portion 3 may have a skin-facing portion 3a that is substantially flat or curved (with a relatively large radius of curvature). The shape of the skin-facing portion 3a when viewed from the front (the shape when viewed in a direction perpendicular to the skin-facing portion 3a) may be any shape, such as a rectangle, a circle, an ellipse, or a polygon. The skin-facing portion 3a may be formed of any material that can transmit light, such as glass. In this embodiment, the skin-facing portion 3a is formed by a light emitting surface. Note that the light emitting surface of the skin-facing portion 3a is exposed, but may be covered by a lens or the like. The skin-facing portion 3a is preferably in a concave shape that is recessed in the vertical direction relative to the skin. In this case, skin treatment by light irradiation can be performed while the concave portion contains cosmetics or the like that contain the object to be penetrated into the skin, thereby enhancing the skin treatment effect.

[0018] A light irradiating unit 30 (not shown in FIG. 1, see FIG. 3) is embedded in the head unit 3. The light irradiating unit 30 generates light that is irradiated to the skin via the skin-facing portion 3a. That is, the light irradiating unit 30 irradiates the skin with light via the skin-facing portion 3a. Note that an optical system such as a light guide may be disposed between the light irradiating unit 30 and the skin-facing portion 3a, or an optical system may not be disposed.

[0019] In this embodiment, the light irradiation unit 30 includes an LED (Light Emitting Diode) 36. Only one LED 36 may be disposed, or multiple LEDs 36 may be disposed. When multiple LEDs 36 are disposed, the multiple LEDs 36 may be disposed, for example, in a plane substantially parallel to the skin facing portion 3a.

[0020] In this embodiment, the light irradiation device 1 is portable, but may be fixed, and may have any form. The light irradiation device 1 may be, for example, in the form of a mask worn on the face or wrapped around the body. The irradiation range of the light irradiation device 1 may be any, and irradiation to the skin may be possible in various forms, such as a form of wide-area irradiation and a form of spot irradiation. The light irradiation device 1 has a head unit 3 separate from the light irradiation unit 30, but the head unit 3 and the light irradiation unit 30 may be integrated.

[0021] FIG. 2 is an explanatory diagram of the characteristics of the light (predetermined light) emitted from the LED 36, in which the horizontal axis represents the wavelength and the vertical axis represents the intensity, and an example of the characteristics is shown.

[0022] The LED 36 is preferably a light source that generates a predetermined light having a central wavelength in a wavelength range longer than 490 nm and equal to or less than 525 nm. The basis (technical significance) of the superiority of this wavelength range (and the wavelength of approximately 505 nm therein) will be described later with reference to Figures 4A, 4B, and 12 onwards. Strictly speaking, 505 nm and its vicinity are blue-green wavelengths, and 525 nm and its vicinity are green wavelengths, but hereinafter, the wavelength range longer than 490 nm and equal to or less than 525 nm may be expressed as "green".

[0023] More preferably, the predetermined light has a central wavelength of approximately 505 nm as shown in Fig. 2. With such a central wavelength, melanin production in the irradiated skin part of the user can be suppressed compared to cases where the predetermined wavelength is not used, as described below. For example, the predetermined light can be irradiated in a manner that has a melanin production suppression effect that is 5% or more, more preferably 10% or more better than when the predetermined light is not irradiated, in the irradiated skin part of the user.

[0024] The predetermined light preferably has a half width at half maximum (see FIG. 2) of ±20 nm or less, and more preferably about ±10 nm, which can maximize the effect of suppressing melanin production in the irradiated skin area of ​​the user.

[0025] The light irradiation unit 30 irradiates a predetermined light, preferably 0.5 mW / cm 2 or more and 62mW / cm 2 A radiation intensity in the range of 11.5 mW / cm 2 or more and 30mW / cm 2 The radiation intensity is set to the following ranges: The test results will be described later with reference to FIG.

[0026] The light irradiation unit 30 irradiates a predetermined light, preferably, 0.09 J / cm 2More than 30J / cm 2 The irradiation energy is preferably in the range of 0.09 J / cm 2 More than 11 J / cm 2 Irradiation is performed with irradiation energy in the following range.

[0027] It is also possible to mount a plurality of LED 36 elements on one chip. Alternatively, the LED 36 may be combined with other LEDs having other central wavelengths on one chip. For example, when the LED 36 and a red LED are combined on one chip, the ratio of the number of green LEDs to the number of red LEDs on one chip may be appropriately adapted.

[0028] FIG. 3 is a diagram showing an outline of a control system for the light irradiation device 1. As shown in FIG.

[0029] The light irradiation device 1 includes a control device 100, to which a power source 90 and an LED 36 are electrically connected. The control device 100 operates based on power from the power source 90 and controls the LED 36. The LED 36 operates based on power from the power source 90 under the control of the control device 100. The power source 90 may include an external power source and / or an internal power source. The internal power source may be a rechargeable battery.

[0030] The control device 100 irradiates the skin with the predetermined light via the LED 36. In this case, the control device 100 may achieve continuous light irradiation for 1 minute or more, in which the irradiation time of the predetermined light accounts for 1 / 2 or more. In this case, light of another wavelength may be irradiated during the time other than the irradiation time of the predetermined light, or no light may be irradiated (i.e., the predetermined light may be irradiated intermittently).

[0031] Furthermore, the control device 100 may control the irradiation of light from the head unit 3 in one or more operation modes. The one or more operation modes may include a predetermined operation mode associated with the melanin production suppression effect, or a predetermined operation mode associated with an effect related to the melanin production suppression effect. In this case, the control device 100 causes the head unit 3 to output a predetermined light in the predetermined operation mode.

[0032] 3A is a diagram showing an example of a hardware configuration of the control device 100. In FIG. 3A, a control target 60 is illustrated in association with the hardware configuration of the control device 100.

[0033] The control device 100 includes a CPU (Central Processing Unit) 11, a RAM (Random Access Memory) 12, a ROM (Read Only Memory) 13, an auxiliary storage device 14, a drive device 15, and a communication interface 17, all connected by a bus 19, as well as a wired transceiver unit 25 and a wireless transceiver unit 26 connected to the communication interface 17.

[0034] The auxiliary storage device 14 is, for example, a hard disk drive (HDD) or a solid state drive (SSD), and is a storage device that stores data related to application software and the like. The wired transceiver 25 includes a transceiver capable of communicating using a wired network. A control target 60 is connected to the wired transceiver 25. However, a part or all of the control target 60 may be connected to the bus 19 or may be connected to the wireless transceiver 26.

[0035] The wireless transceiver 26 is a transceiver capable of communicating using a wireless network. The wireless network may include a wireless communication network for mobile phones, the Internet, a Virtual Private Network (VPN), a Wide Area Network (WAN), and the like. The wireless transceiver 26 may also include a Near Field Communication (NFC) unit, a Bluetooth (registered trademark) communication unit, a Wireless-Fidelity (Wi-Fi) transceiver unit, an infrared transceiver unit, and the like. The control device 100 may communicate with a server (not shown) via the wireless transceiver 26 to acquire various pieces of information.

[0036] The control device 100 may be connectable to a recording medium 16. The recording medium 16 stores a predetermined program. The program stored in the recording medium 16 is installed in the auxiliary storage device 14 of the control device 100 via the drive device 15. The installed predetermined program can be executed by the CPU 11 of the control device 100. For example, the recording medium 16 may be a recording medium that records information optically, electrically or magnetically, such as a CD (Compact Disc)-ROM, a flexible disk, or a magneto-optical disk, or a semiconductor memory that records information electrically, such as a ROM or a flash memory. The recording medium 16 does not include a carrier wave.

[0037] Next, the effect of the above-mentioned predetermined light (the effect of suppressing melanin production) will be further described with reference to test results and the like.

[0038] Visible light is less invasive to the body, so various studies have been conducted on its effects on the body for applications in the fields of medicine and cosmetic dermatology (Imagawa et al., Japan Medical Journal, 32, 444 (2012)). For example, it has been reported that red light prevents skin aging, and green and yellow light play an important role in suppressing excessive cell activity.

[0039] Melanin, which causes pigmentation in the skin, is produced in melanocytes and plays an important role in preventing DNA damage from harmful ultraviolet rays, but it is also the cause of spots, so there is a high demand for improving this. Therefore, we tested the effectiveness of green LED light, which suppresses cell activity, to see if it also affects melanoma activity and reduces melanin production.

[0040] The inventors of this application requested Toin University of Yokohama to carry out the following test in order to verify the melanin production inhibitory effect of green LED. The melanin production inhibitory effect was verified using mouse-derived B164A5 cells (B16 melanoma cells, Riken BRC) and human-derived melanoma cells (HMV-II cells, KAC Co., Ltd.) obtained at the university. In addition, Ushio Inc.'s SMT525 (wavelength 525 nm) and SMT505 (wavelength 505 nm) were used as the light source for the green LED.

[0041] (Cell survival rate using B16 melanoma cells) B16 melanoma cells were cultured in a 6-well plate at 1 × 10 4 and 2 × 10 4 The cells were seeded at 1000 x 1000 cells / mL and cultured at 37°C under 5% CO2 for 3 days, then replaced with phenol red-free medium. Irradiated with green LED once a day for 3 days, and cultured for 1 day. Cell Counting Kit-8 (Dojindo Chemical Industries) was then added and cultured for 3 hours. After culture, the medium was dispensed, the absorbance at 450 nm was measured, and the number of surviving cells was calculated. The higher the absorbance at 450 nm, the higher the number of surviving cells.

[0042] (Evaluation of inhibition of melanin production by B16 melanoma cells) B16 melanoma cells were cultured in a 6-well plate at 1 × 10 4 and 2 × 10 4 The cells were seeded at 1000 x 1000 cells / mL and cultured at 37°C under 5% CO2 for 3 days, then replaced with a phenol red-free medium containing 100 nM of the melanin synthesis inducer α-MSH. After irradiating with green LED once a day for 3 days and culturing for 1 day, the cells were washed with 1 mL of PBS(-) and dissolved in 2 mol / L aqueous sodium hydroxide solution containing 10 wt% dimethyl sulfoxide (DMSO), and the amount of melanin produced was measured from the absorbance at 405 nm. Furthermore, the amount of cell-derived protein was measured using an RC DCTM protein assay (BioRad). Based on the measurement results, the amount of melanin per amount of cell-derived protein was calculated.

[0043] (Melanin production suppression effect by green LED light irradiation) It was confirmed that irradiation with green LED light of wavelengths 505 nm and 525 nm reduced the number of viable B16 melanoma cells and reduced the amount of melanin production. This tendency was more pronounced with green LED light of 505 nm. This can be seen from the test results shown in Figures 4A and 4B. Figure 4A shows the number of viable B16 melanoma cells when irradiated with green LED light of wavelength 505 nm, and Figure 4B shows the number of viable B16 melanoma cells when irradiated with green LED light of wavelength 525 nm. In this test, the initial cell concentration was 1 x 10 4 (Cells / mL) and 2×10 4 (Cells / mL), and the concentrations after 30 and 60 minutes were measured, respectively.

[0044] (Evaluation of inhibition of melanin production by human-derived HMV-II melanoma cells HMV-II) It has been reported that the drug sensitivity to skin whitening agents differs between mouse-derived B16 melanoma cells and human-derived HMV-II melanoma cells. In the evaluation of the B16 cells, the melanin production suppression effect was more pronounced with 505 nm green LED light, so the effect was evaluated for HMV-II cells by narrowing the wavelength to 505 nm.

[0045] Unlike B16 cells, the effect of the melanin synthesis inducer α-MSH on the proliferation of melanoma cells was low in HMV-II cells, so theophylline, an enhancer of MSH, was used as a melanin synthesis inducer to evaluate HMV-II cells. 1×10 4 Dispense 2 mL of HMV-II cell suspension (1 × 10 cells / mL) into a 66-well plate. 4The cells were seeded at 1000μL / mL and cultured at 37℃ under 5% CO2 for 3 days, then replaced with 2mL of phenol red-free medium containing 25μL of Theophylline after culturing in 40mM. After irradiating with 505nm LED light once a day for 3 days, the cells were cultured for 1 day, and the cells were dissolved in 2mol / L sodium hydroxide solution with 300μL of 2M NaOH solution containing 10wt% dimethyl sulfoxide (DMSO), and the amount of melanin produced was measured from the absorbance at 405nm. Furthermore, the amount of cell-derived protein was measured using RC DCTM protein assay (manufactured by BioRad). Based on the measurement results, the amount of melanin per amount of cell-derived protein was calculated.

[0046] (HMV-II cell survival rate) HMV-II cells were cultured in a 6-well plate at 1 × 10 4 The cells were seeded at 1000 x 1000 cells / mL and cultured at 37°C under 5% CO2 for 3 days, after which the medium was replaced with phenol red-free medium. The cells were irradiated with 505 nm LED once a day for 3 days, and then cultured for 1 day. Cell Counting Kit-8 (Dojindo Chemical Industries) was then added and cultured for 3 hours. After culture, the medium was dispensed and the absorbance at 450 nm was measured. After measurement, the survival rate was calculated as a relative value to the absorbance at 450 nm without LED light irradiation.

[0047] (Melanin production suppression effect by green LED light irradiation) It was confirmed that irradiation with 505 nm LED light reduced the survival rate of HMV-II cells and reduced melanin production.

[0048] It was verified that green LED light irradiation is effective in suppressing melanin production in both B16 cells and HMV-II cells. This can be seen from other test results shown in Figures 5A to 5D. Other tests shown in Figures 5A to 5D were also conducted in the same manner as the test described above with reference to Figures 4A and 4B. Note that Figure 5E is a table showing the evaluation results obtained from the test results of Figures 5A to 5D. As can be seen from these, 505 nm has a higher melanin production suppression effect than 525 nm, and it was more pronounced at 20 minutes than at 10 minutes. In addition, 505 nm showed suppression even at 30 and 60 minutes, but 525 nm did not show any suppression effect at 30 minutes, but did show suppression at 60 minutes.

[0049] In this embodiment, the effect of suppressing the production of melanin, which causes spots, was observed when using green LED light, particularly at a wavelength of 505 nm. This can be seen from the test results shown in Figures 6A to 7B. Figures 6A and 6B show the results of the first and second tests, respectively, and Figures 7A and 7B show the results of the first and second tests, respectively. The other tests shown in Figures 6A to 7B were also carried out in the same manner as the tests described above with reference to Figures 4A and 4B.

[0050] Figures 8 to 11 are diagrams showing other test results, where Figure 8 is a table showing the relationship between the radiation intensity of green LED light and the effect (the effect of suppressing melanin production), and Figures 9 to 11 are graphs showing the relationship between the radiation intensity of green LED light and the effect. Figure 11A is a graph showing another test result regarding the relationship between the radiation intensity of green LED light and the effect.

[0051] Another test, shown in Figures 8 to 11, was carried out as follows. B16 melanoma 4A5 was provided by Riken BRC. In the contents of this experiment, the word "cells" used hereafter refers to these. The cells and cell culture were performed as described in steps S1 to S3 below, and the following media was used. Dulbecco's Modified Eagle Medium (DMEM, Cat No. 10566-016, Gibco, USA) containing 10.0% (v / v) Fetal Bovine Serum (FBS, Cat No. SH30071.03, Hyclone®, UK) and 1.0% (v / v) antifungal agent (Antibiotic-Antimycotic 100X, Cat No. 15240-062, Invitrogen, USA) was used. DMEM containing 10% FBS was prepared containing 100 nM α-Melanocyte stimulating hormone (α-MSH, Cat No. M4135, Sigma-Aldrich, USA) and 100 μM theophylline (Cat No. T1633, Sigma-Aldrich, USA). Step S1: Cell culture and passaging The cells were seeded in a 60 mm dish (Cat No. 353002, Falcon (registered trademark), USA) at a density of 3.0 × 10 5 cells / dish and cultured in a CO 2 incubator (CO 2 concentration = 5%, 37°C) for 24 hours. Step S2: Irradiate green LED light The medium was removed, washed with phosphate buffer saline (PBS(-), Cat No. 198601, Nissui, Japan), and then replaced with 8 mL of Hanks' balanced salt solution (+) (HBSS(+), Cat No. 084-08965, Wako, Japan), and the irradiation device was applied according to the irradiation conditions. The HBSS(+) was then removed and replaced with 3 mL of test medium, and the cells were cultured for 72 hours. The irradiation time was set to 3 minutes. Step S3: After culturing and washing with PBS, 2 mL of alamarBlue solution, which was prepared by diluting alamarBlue (registered trademark) (Cat No. DAL1100, Invitrogen (registered trademark), USA) 10 times with serum-free DMEM, was treated to the cells and cultured at 37 ° C for 2 hours in a CO2 incubator. The alamarBlue solution was collected and placed in a 96-well plate (Cat No. 9017, costar, USA) at 200 μL, and the absorbance at 570 nm and 600 nm (OD570, OD600) was measured using a microplate reader (SPARK (registered trademark) 10M, TECAN, Switzerland). The alamarBlue solution was used as a blank. The alamarBlue solution was removed from the 60 mm dish, washed with PBS (-), and then 1 mL of 1 M aqueous sodium hydroxide solution containing 10% DMSO was added to solubilize melanin, followed by incubation at 85 ° C for 10 minutes. 100μL of the melanin solution was placed in a 96-well plate, and the absorbance at 405nm (OD405) was measured using a microplate reader. The cell viability of the LED application group was calculated by setting the OD570-600 of the control as 100%. The melanin production rate was also calculated by setting the OD405 of the control as 100%. Furthermore, the melanin production rate per cell was calculated by dividing the OD405 of the control and LED irradiation application groups by the OD570-600 measured with alamarBlue. A significance test was performed between the control and LED application groups using an unpaired t-test. All tests were two-sided, with a significance level of less than 5%.

[0052] As can be seen from Figures 8 to 11, when B16 melanoma cells were irradiated with a green LED (505 nm), the melanin production rate was significantly lower than that of the control at all outputs, indicating that melanin production was suppressed. 2 ~11.5mW / cm 2 The highest output of 11.5mW / cm 2In the application, the melanin production rate per cell was also significantly lower than in the control, and the highest output among these conditions tended to suppress the production ability. From these results, as described above, the radiation intensity of the predetermined light from the light irradiation unit 30 is preferably 0.5 mW / cm 2 More preferably, it is in the range of 11.5 mW / cm 2 That is all that can be said. Also, Fig. 11A shows the difference in effect when irradiating green LED light with a wavelength of 520 nm at different radiation intensities. The test shown in Fig. 11A was also carried out in the same manner as Fig. 8 and the like. In Fig. 11A, the control shows the test result in which nothing was irradiated. Here, the control was compared to the test result of 9 mW / cm 2 and 62 W / cm 2 The results of each test are compared. Graphs A, B, and C correspond to cell viability, melanin production rate, and melanin production rate per cell, respectively.

[0053] 11A, when the radiation intensity of the predetermined light from the light irradiating unit 30 becomes higher than a certain level, the effect does not become significantly large (i.e., it becomes saturated). From these, as described above, the radiation intensity of the predetermined light from the light irradiating unit 30 is preferably 0.5 mW / cm 2 or more and 62mW / cm 2 More preferably, it is in the range of 11.5 mW / cm 2 or more and 62mW / cm 2 In terms of power consumption, it can be said that the range is 62 mW / cm 2 Instead, 30mW / cm 2 It can be said that an upper limit of about this level is desirable.

[0054] In the tests shown in Figs. 8 to 11A, the irradiation energy of the predetermined light from the light irradiation unit 30 was 0.09 J / cm 2 More than 11 J / cm 2 In addition, taking into account other test results disclosed in this specification, the irradiation energy of the predetermined light from the light irradiation unit 30 was in the range of 0.09 J / cm 2 Above 45J / cm2 Tests were conducted in the following ranges: 2 More than 11 J / cm 2 Effective effects were also confirmed within the following ranges.

[0055] The light irradiation device 1 may irradiate the above-mentioned green LED light to the dry skin of the user, or may irradiate the green LED light to the skin to which a gel or liquid containing a substance to be permeated has been applied. In this case, the substance to be permeated is arbitrary. The substance is a substance that can be applied to human skin, and typically may be a substance that can be expected to have various effects such as a cosmetic effect.

[0056] Next, the preferred wavelength range of light to be irradiated onto the skin will be further described with reference to FIG.

[0057] The studies described above with reference to Figures 4A and 4B above showed that exposure to green LED light at wavelengths of 505 nm and 525 nm reduced the survival and melanin production of B16 melanoma cells.

[0058] Figure 12 shows other test results, and shows the test results when LED light of wavelengths 450 nm, 520 nm, and 850 nm (near-infrared wavelengths) was irradiated. Figure 12 shows the test results for cell survival rate, melanin production rate, and melanin production rate per cell when LED36 was irradiated with wavelengths of 450 nm, 520 nm, and 850 nm, respectively. In Figure 12, the control shows the test results when nothing was irradiated.

[0059] It should be noted that the test results shown in FIG. 12 were conducted by a different institution than the tests described above with reference to FIGS. 4A and 4B, but the test methods were substantially similar.

[0060] As can be seen from Figure 12, the melanin production inhibition was confirmed to be predominant at wavelengths of 520nm and 450nm. In other words, it was shown that the survival number of B16 melanoma cells decreased, and the amount of melanin production decreased. It was also suggested that the melanin production inhibition effect may be greater at 520nm than at 450nm. Although some tendency for inhibition was observed at a wavelength of 850nm, there was no significant difference, and it was the lowest result. Fig. 13 shows further test results, which are related to the difference in the melanin production suppression effect caused by the difference in three types of wavelengths. Fig. 13 shows the test results of the melanin production rate per cell when irradiated with LED36 wavelengths of 505 nm, 525 nm, and 630 nm (red wavelength). Note that in Fig. 13, the control also shows the test results when nothing was irradiated.

[0061] It should be noted that the test results shown in FIG. 13 were conducted by a different institution than the tests described above with reference to FIGS. 4A and 4B, but the test methods were substantially similar.

[0062] As can be seen from FIG. 13, no significant inhibition of melanin production was observed at wavelengths of 525 nm or 630 nm, as was observed at a wavelength of 505 nm. Fig. 14 shows further test results, specifically test results relating to differences in melanin production suppression effects caused by differences in four types of wavelengths. Fig. 14 shows test results for cell survival rate when irradiated with LED36 wavelengths of 470 nm (blue wavelength), 490 nm, 505 nm, and 525 nm. Note that in Fig. 14 as well, the control shows the test results when nothing was irradiated.

[0063] It should be noted that the test results shown in FIG. 14 were conducted by a different institution than the tests described above with reference to FIGS. 4A and 4B, but the test methods were substantially similar.

[0064] As can be seen from Figure 14, the survival rate of B16 melanoma cells was lower at wavelengths of 470 nm, 505 nm, and 525 nm than at a wavelength of 490 nm. In other words, the superiority of wavelengths of 470 nm, 505 nm, and 525 nm over a wavelength of 490 nm (superiority in terms of melanin production suppression effect) was demonstrated.

[0065] Fig. 15 is a diagram showing the test results regarding the expression amount of keratin 10. Fig. 15 shows the test results regarding the expression amount of keratin 10 when irradiated with LED 36 having wavelengths of 470 nm, 505 nm, and 590 nm (yellow wavelength).

[0066] The test method is outlined below.

[0067] (Step S1) Cell pre-culture Human epidermal keratinocytes (NHEK) were induced to sleep in a T-75 flask using medium and cultured in a CO2 incubator (5% CO2, 37°C, humidified). When the cells reached approximately 80% confluence, they were subcultured in a T-225 flask, cultured until the required cell number was obtained, and then used for the subsequent test. The cell subculture method was as follows. After washing the cells with PBS (- / -), the cells were detached using 0.05% Trypsin-EDTA, and trypsin neutralizing solution was added to neutralize trypsin. Next, the cell suspension was collected in a centrifuge tube and centrifuged (room temperature, 180xg, 5 min). The supernatant was removed, new medium was added to suspend the cells, and the number of cells was counted. The cells were suspended to the desired cell density using medium, and seeded in the incubator to be used in the test.

[0068] (Step S2) Cell processing The cells were seeded in a 60 mm dish at 900,000 cells / dish / 3 mL. The day after seeding, 5 mL of medium was added, making a total of 8 mL, and the device treatment was performed for 30 seconds. Treatment was performed every 24 hours ± 1 hour, for a total of three facial treatments. Calcium chloride was added to the medium at the same time as the first device treatment, making 8 mL. Treatment was then performed for 72 hours.

[0069] (Step S3) RNA extraction 24 hours after the final instrumentation, RNA was extracted using the RNeasy Plus Mini Kit according to the kit's protocol. After RNA extraction, the concentration was measured using NanoDrop Eight and the RNA was stored at -80°C.

[0070] (Step S4) Quantitative PCR One Step real-time RT-PCR was performed using the QuantiTect Probe RT-PCR Kit included with the FastLane Cell Probe Kit with the composition shown in the table below. The RNA sample was diluted to approximately 100ng / μL. The RT-PCR reaction was performed under the following conditions: 50℃·30min-95℃·15min-(94℃·15sec-60℃·60sec)×40 cycles. The GAPDH gene was used as the internal standard gene.

[0071] As can be seen from Fig. 15, the expression level of keratin 10 was significantly higher at a wavelength of 505 nm than at wavelengths of 470 nm and 590 nm. In other words, the superiority of the wavelength of 505 nm over the wavelengths of 470 nm and 590 nm (superiority in the expression effect of keratin 10) was demonstrated.

[0072] Here, we will explain the mechanism of turnover. The epidermis is arranged in four layers: the basal layer, the spinous layer, the granular layer, and the stratum corneum. At the cellular level, turnover occurs in four stages: cell proliferation in the basal layer, keratin (K10) synthesis in the spinous layer, cell death (apoptosis and necrosis) in the granular layer, and cleavage by a proteolytic enzyme (KLK8) in the stratum corneum. In human skin, the process in which epidermal cells are generated in the basal layer, mature as they migrate toward the upper layers, and are formed by exfoliation at the stratum corneum is called turnover.

[0073] If keratin synthesis decreases, the epidermal structure cannot be maintained, resulting in wrinkles and sagging. With rapid turnover, immature epidermal cells are exposed to the outside world before they have become keratinized. Excessive turnover can also cause the pathology of atopic dermatitis. With slow turnover, keratin that should have peeled off as dandruff remains and thickens. Furthermore, abnormal delays can cause psoriasis, keratosis, and other conditions. Therefore, indicators other than cell proliferation are also essential factors when considering normal turnover.

[0074] Thus, keratin 10 is expressed in the spinous layer and is useful in the turnover process, suggesting that normal turnover is proceeding.

[0075] In addition, there is a paper that reports that blue light irradiation inhibits cell proliferation and collagen expression in human skin fibroblasts by inhibiting the TGF-β signaling pathway (Ge Ge et al., "Induced skin aging by blue-light irradiation in human skin fibroblasts via TGF-β, JNK and EGFR pathways," Journal of Dermatological Science). From this point of view, it is strongly inferred that the 505 nm wavelength is more advantageous than the 470 nm wavelength.

[0076] From the test results shown in Figures 4A, 4B, and 12 to 15, it can be seen that irradiating the skin with light having a central wavelength in the wavelength range longer than 490 nm and equal to or shorter than 525 nm is advantageous in terms of the effect of inhibiting melanin production and the effect of expressing keratin 10, compared to irradiating the skin with light having a central wavelength in other wavelength ranges.

[0077] Although each embodiment has been described above in detail, the present invention is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. In addition, it is also possible to combine all or a plurality of the components of the above-described embodiments. [Explanation of symbols]

[0078] 1. Light irradiation device (skin treatment device) 2 Grip part 3 Head section 3a Skin-facing area 30 Light irradiation unit 36 LEDs (Light Emitting Diodes) 100 Control device (control unit)

Claims

1. A light source that generates a predetermined light having a center wavelength in a wavelength range longer than 490 nm and shorter than 525 nm, A melanin production inhibiting device capable of irradiating skin with the predetermined light from the light source.

2. The melanin production inhibiting device according to claim 1 , wherein the predetermined light has a central wavelength of 505 nm.

3. 3. The melanin production inhibiting device according to claim 1, wherein the predetermined light is irradiated at a radiation intensity of 0.5 mW / cm2 or more and 62 mW / cm2 or less.

4. 3. The melanin production inhibiting device according to claim 1, wherein the predetermined light is irradiated with an irradiation energy in the range of 0.09 J / cm2 or more and 45 J / cm2 or less.

5. The melanin production inhibiting device according to claim 1 , wherein the light source includes an LED.

6. A control unit that controls the illumination of the light in one or more operation modes, the one or more operation modes include a predetermined operation mode associated with a melanin production inhibition effect or a predetermined operation mode associated with an effect related to the melanin production inhibition effect, The melanin production inhibiting device according to claim 1 , wherein the control unit outputs the predetermined light in the predetermined operation mode.

7. The device has an irradiation unit that can be opposed to a part of a user's body, The melanin production inhibiting device according to claim 6 , wherein the control unit outputs the predetermined light alone from the irradiation unit in the predetermined operation mode.

8. 3. The melanin production inhibiting device according to claim 1, wherein continuous light irradiation for one minute or more is possible, with the proportion of the irradiation time of the predetermined light being 1 / 2 or more.

9. A method for inhibiting melanin production, comprising irradiating human skin with a predetermined light having a central wavelength in a wavelength range longer than 490 nm and shorter than 525 nm.

10. The method for inhibiting melanin production according to claim 9 , wherein the predetermined light has a central wavelength of approximately 505 nm.

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