Skin is composed of the epidermis and the dermis, which are separated by the epidermal basement membrane. This membrane plays an important role in maintaining the skin structure by forming anchoring complex. It also controls proliferation and differentiation of basal cells in the epidermis and maintains the polarity of the epidermis. Disruption and reduplication of the epidermal basement membrane have been reported in skin from elderly people. Indeed, they are also seen in facial skin of people in their late 20s and early 30s, when changes in skin surface texture take place. Such damage and alteration are thought to be signs of early aging of skin, which might lead to the formation of wrinkles and sagging. Therefore, early basement membrane care could be an effective approach to prevent apparent skin aging. Laminin 5 is a glycoprotein and a component of anchoring complex in the epidermal basement membrane, playing an important role in the adhesion of epidermis to dermis. Purified laminin 5 stimulates the formation of epidermal basement membrane in a skin-equivalent model and in epidermal sheet grafting in vivo. Furthermore, basement membrane formation is also enhanced by substances that stimulate laminin 5 synthesis in the skin-equivalent model, as well as by purified laminin 5. These results suggest that laminin 5 itself and substances that stimulate laminin 5 synthesis could be effective players in basement membrane care.

View full abstract

Nail enamels are very popular as a point makeup product next to lipsticks. Recently the number of user steadily increases with the prosperity of nail salons and nail art. This popularity of nail enamel put it more important position. The qualities required in nail enamel are speed of drying, even formation of film with high gloss, non-irritant against the nail, and long-lasting luster and finish. There is a strong growing demand for quicker drying nail enamels in recent markets, and several products are found. However, with conventional technologies, there is a limit in reducing the drying time, because of its poor appearance. This paper describes the technologies of fast drying nail enamels with the example of “dip-in-water” nail enamel. Although the process of drying is usually regarded as solvent evaporation, in the case of developing this new nail enamel, the drying of nail enamel is considered as precipitation process of film former. This unique idea made it possible to reduce drying time dramatically with the help of water.

View full abstract

In the functions of the cosmetics, one of the crucial points is to represent the stereoscopy. Now its objective evaluation is required. Though the facial stereoscopy by the make-up is created through emphasizing the light and shade, its effectiveness until now has been evaluated by human senses such as the sense of sight. Obtaining an objective evaluation is quite difficult. A series of methods that are proposed by this study can help resolve this problem. This study proves that facial light and shade can be directly measured in a short time, enabling the calculation of the 3-D facial traits and stereoscopy brought by the traits. The assembled device was designed to irradiate light to an subject in various directions at a fixed distance and then make an impression of the subject, ready to be processed. By the image processing through the average values and the variance values calculated previously, it became possible to reproduce the subject traits of the light and shade on a image. Then by standardizing the analyzed results of the subjects, the conventional facial traits which are usually known were successfully reproduced. Meanwhile the difference in the effect brought by applying the foundations became obvious. It was discovered by analyzing the subject with two kinds of foundations which differed in the optical traits. Consequently this series of methods is considered greatly efficient in evaluating the facial stereoscopy, objectively and universally.

View full abstract

A method is proposed for visualizing melanin masses in pigmented regions of the epidermis. A multispectral image of the pigmentation is obtained at dominant wavelengths of 400, 550 and 700nm and the luminance of each pixel is converted to a spectral reflectance. Since the spectral reflectance can be expressed linearly, spectral reflectance was then determined in 10nm steps (41 different wavelengths) in the visible region (380-780nm). The spectral reflectance of pixels at each wavelength was reconverted to luminance to reconstruct a single multispectral image. Then, the multispectral image at each of the 41 wavelengths was converted to a binary image, and the binary images were laminated into a single composite image to provide visualization of the melanin masses that cause pigmentation in the epidermis. Using this method, it is possible to obtain three-dimensional visualization of melanin masses that cause pigmentation in freckles, chloasmas, dark circles and moles, and to visualize changes in melanin distribution in the epidermis following suntan-induced pigmentation.

View full abstract

Skin microbial flora was collected from the skin surface of the cheek and the former forehead of healthy men and women, and quantification and identification of the bacilli were performed. When the number of aerobic bacteria was compared between the sampling regions, the higher numbers of aerobic bacteria were detected in the cheek than the forehead in men. On the contrary, the higher numbers of aerobic bacteria were detected in the forehead compared to the cheek in women. Isolation and identification of the aerobic bacteria showed that Staphylococcus epidermidis was dominant in these samples. S. epidermidis was detected from all 48 subjects, and the detection rate was 100%. When the number of anaerobic bacteria was compared between the sampling regions, the higher numbers of anaerobic bacteria were detected in the forehead than the cheek both in men and women. Isolates from men contained higher numbers of anaerobic bacteria than those from women in both sampling regions. Propionibacterium acnes was a dominant species in these samples. P. acnes was detected from all 48 subjects, and the detection rate was 100%. Staphylococcus capitis, which belongs to aerobic bacteria, was detected in 17 men among 19 men, while it was detected in only one woman among 29 women. Thus, the differences of species types in the aerobic bacteria were observed between men and women. Study of the enzyme activity of S. epidermidis, the dominant species of the aerobic bacteria, showed that these activities were differed for samples from every subject, and were differed also for the bacteria collected from the same subject. The rate of subjects which had S. epidermidis with acetoin production ability was decreased along with aging. On the contrary, the rate of subjects which had S. epidermidis with urease activated ability was increased along with aging.

View full abstract

We have reasoned that by either enhancing inhibition effectiveness of tyrosinase activity or by inhibiting the activities of both tyrosinase and TRP-1, we should be able to develop more effective whitening cosmetics. We found 4-n-butylresorcinol (BR) to have strong inhibitory effect against melanogenic enzymes which are responsible for hyperpigmentation. BR reversibly inhibited melanin production in B16 mouse melanoma cells without any effects on cell growth, and its potency was stronger than that of arbutin or kojic acid which are widely used in whitening cosmetics. Topical application of 0.3% BR lotion prior or posterior to UVB-irradiation effectively suppressed UVB-induced hyperpigmentation in human. In our extensive consumer usage test involving 449 healthy females, a large proportion of subjects felt there were improvements in conditions of pigmentation, skin darkness, and freckles increased in as little as 1 month. These experimental data indicated that BR is an effective skin whitening agent which can be safely used in cosmetics. Furthermore, a trial to evaluate clinical effects of 0.3% BR lotion in patients with liver spot was made. BR lotion was evaluated as slightly useful or better in 52 (83.9%) out of 62 subjects. Accordingly, we concluded that BR can be used in the clinical treatment of liver spot.

View full abstract

Generally, women recognize aging with the appearance of wrinkles at the corner of the eyes or around the mouth. Thus one of the essential aims of cosmetics is the development of substances for wrinkle repair. In the process of developing cosmetics for this purpose, it is essential to establish a highly reproducible method for determining wrinkle depth. Several methods exist for this purpose, which include 3-dimensional analysis by laser light, image analysis, and conventional scoring. All of these methods use image analysis to determine wrinkle depth. However, each of these methods produce different results depending upon the way the image is obtained and the type of analysis used. We thus tried to establish a new evaluation method which uses image analysis in combination with a standard scale. This study shows that our method is highly reproducible and was very suitable on evaluation of the wrinkle depth.

View full abstract

We have created a “long-lasting” makeup foundation by applying two types of perfluoroalkylethyl acrylate (FA) copolymers. The two FA copolymers are a hybrid polymer which includes hydrophobic comonomers and a SR polymer which includes hydrophilic comonomers. The properties of these FA copolymers have already been discussed in our first report. In this report, FA copolymers were applied to the surface of cosmetic powders. Makeup foundation containing these powders was tested for surface deterioration. Test results showed that the foundation containing hybrid polymer-treated powders had a higher tolerance against makeup deterioration than the one containing silicone-treated powders. Moreover, the foundation containing powders treated by both hybrid and SR polymers demonstrated an even higher tolerance. These results indicated that applying both types of FA copolymer treatment at the same time prevents makeup deterioration when both sweat and sebum are present on the skin.

View full abstract

Subjects were given a sleep deprivation as a stress to check the differences between activation of protease (trypsin) in stratum corneum with and without fragrance in sleeping time. Stratum corneum were collected from the inner upper arm by the tape stripping method. Peptidyl-MCA was added to them and incubated for 2h at 37°C to measure the fluorescent light of produced MCA. This result showed that the protease activation with fragrance was significantly higher than one without. We thought it would be possible that the stress alleviation effect and refreshing sleep caused by this pleasant fragrance gave good influences on the homeostatic mechanisms.

View full abstract