Regarding to the pathogenesis of skin aging, oxidative stress, i.e. photoaging, and glycative stress play a significant role. Once skin is exposed to ultraviolet (UV) rays, various kinds of skin damage occurs, mediated by reactive oxygen species (ROS) and free radicals. The stimulated melanin production in pigment cells damages DNA in keratinocytes and participates in spot formation. The stimulated fibroblast production is involved in wrinkle formation. Glycative stress, a secondary factor for skin aging, is a pathophysiological condition attributed to the excessive production of reducing sugar, lipids and alcohol-derived aldehydes. The aldehyde reacts with biological materials to form carbonyl proteins and/or advanced glycation end-products (AGEs). Furthermore, AGEs bind to RAGE (receptor for AGEs) and stimulate inflammatory cytokines in immune-response cells and fibroblasts. The glycative stress causes regressive changes related to skin aging. Glycated collagen participates in the reduction of skin elasticity and glycated elastin promote slack skin. Recent reports show AGEs stimulate pigment cells to produce melanin, probably participating in spot formation. The development of anti-glycative cosmetics is important and expected in future.
Glossiness is one of the most important quality components of lip rouge. However, an objective and quantitative evaluation method has yet to be established. We aimed to develop a method for image-based lip glossiness measurement by focusing on the texture design of lip rouge, including “pearly” and “glossy” textures. Initially, the correlation between visual glossiness and the image statistic parameter “skewness”, which has been used in previous glossiness perception studies, was evaluated. Skewness showed a good correlation with the visual glossiness of glossy texture lip rouge (correlation coefficient r=0.65), though not with that of pearly texture lip rouge (r=0.21). Next, we developed a new image statistic parameter termed “RMS contrast”, which was considered to have a good correlation with the visual glossiness of pearly texture lip rouge. To evaluate the efficacy of RMS contrast, image statistic parameters and visual glossiness scores of textureenhanced lip rouges (glossy, pearly, and matte) were determined and compared. The present results showed that skewness showed a good correlation with the glossiness of glossy lip rouge, while RMS contrast showed that with pearly lip rouge. In addition, use of a multiple regression equation with these two image statistic parameters allowed for effective evaluation of visual glossiness with good estimation accuracy (r=0.82).
Holistic beauty is a novel concept upholding the idea that all aspects of people's needs including psychological, physiological and social should be taken into account and seen as a whole. This concept has been spreading in the beauty industry, recently. According to this concept, since real beauty is based on skin health and mental health, it is important to care for both aspects of skin conditions at the same time. The odor component of an aromatic product, which is a typical therapy for improvement of mental health, was traditionally used for assuagement of skin health. The mechanism of odor signal transduction has been clarified in the past studies. However, there are few reports that indicate the degree of sedative effect of odor components. Rosa damascena is one of the most popular and common naturally derived fragrances. Although it has been traditionally used for the achievement of a sedative effect, there are few reports regarding how it works on physical and mental relaxation. In general, preference and sensitivity to aromatic compounds should be varied in accordance with gender, race and age; therefore, it has been considered that it is difficult to define the physiological effect of these aromatic compounds on relaxation. In this study, our goal is to establish a systematic quantitative evaluation method to identify the mechanism of the sedative effect of Rosa damascena oil on physical condition, by focusing on the human autonomic and central nerve system by using integrative physiological techniques.
Hair receives external damage such as heat, ultraviolet rays, and friction on a daily basis, and it is necessary to prevent damage by daily hair care such as shampoo and conditioner. By incorporating a cationic polymer in the shampoo, a complex of a shampoo cleansing component and a cationic polymer, which is called “coacervate”, is formed at the time of shampooing, and the feeling of creaking at the time of rinsing is reduced. On the other hand, the coacervate sorbed in the hair may enhance the effect of the conditioner used after shampooing. This time we report on the development of a novel cationic polymer which improves the conditioning effect at shampooing and the sorptive property of the conditioner after shampooing. The cationic polymer was determined by examining the type of cation, degree of cationization, molecular weight, and hydrophobic group. The effect on hair was examined by friction coefficient, contact angle measurement and the like. The compatibility with shampoo wash components and the degree of coacervate formation are also reported.
Silk is one of the main ingredients in cosmetics, and its function is skin moisturization and protection of both hair and skin. In this study, a silk nanofiber suspension was prepared using a wet high pressure jet mill, and its properties were evaluated. The suspension was dried and observed using field-emission scanning electron microscopy, and its specific surface area was measured using the Brunauer-Emmett-Teller (BET) method. For these results, it was confirmed that the silk was in the form of nanofibers. The silk nanofiber suspension was then mixed with cellulose nanofibers or a carbomer, and changes in its viscoelastic properties were measured. When only a small amount of cellulose nanofibers was added, the viscosity of the suspension increased, but no precipitation was observed. In the case of the suspension being mixed with a carbomer, a silk nanofiber gel could be easily prepared. It was found that prototype cosmetics to which silk nanofibers were added could retain skin moisture for a longer time than those without silk nanofibers.