Sunscreen cosmetics have become indispensable in daily life due to the widespread recognition of the harmful effects of UV rays on the human body and the growing awareness of UV protection. These sunscreen cosmetics contain both inorganic UV filters and organic UV filters that have a UV protection effect. In this report, the characteristics of titanium dioxide and zinc oxide, which are widely used as inorganic UV filters, and the latest material development will be highlighted.

Over time biological skin properties change with age, which is caused by both external and internal factors such as UV and hormone balance. In particular, skin parameters of growing children differ depending on when they are measured. Many reports have been presented of the skin characteristics of adults and children from measurements on the inner arm or face. But there have been very few studies on scalps. Recently the importance of microbiome on the skin has been discussed and it seems to be highly related with skin parameters. In this report, we examined the biophysical measurements and analyzed the microbiome on the scalps of a group of three-year-old girls and their mothers. We discovered many differences in their microbiome between the children and the mothers who lived in same environment. In skin parameters, the amounts of sebum and pH of children's scalp were significantly lower than those of mothers, while the volume of sweat was remarkably higher and skin conductance also tended to be higher than for mothers. From our microbiome analysis, children have many varieties of genera existing on the scalp compared with mothers. Principal component analysis (PCA) from our microbiome data suggested that different bacteria contribute to the microbiome on the scalps of children and mothers: Streptococcus for children and Cutibacterium for mothers.

Eye products are important for many people as a tool to improve interpersonal impressions, but the dissatisfaction with usability is known to increase with age. Although the change in the physical properties of eyelid skin due to aging is considered to be one of the major factors that change the usability of eye makeup products, the detailed relationship is still unclear. The main evaluation methods for eye makeup usability are sensory evaluations, but they cannot separate the influence of individual differences from that of aging. It is difficult to objectively evaluate eyelids due to their characteristic shape and sensitive parts. For objective evaluation without using human skin, artificial skin models are useful tools. However, the existing models did not consider the effects of physical properties with age. In this study, we prepared various eyelid models with different artificial skin parameters to consider different ages, while incorporating changes of eyelid skin structure with age and the anatomical structure of eyelids. To select the appropriate model for each age, we evaluated the touch sensation and movement of these eyelid models, and then compared them with those of human eyelids of different ages. These age-specific eyelid models reproduced the declined usability of eyeshadow and eyeliners on aged human skin, suggesting that the physical properties of eyelid skin affect the usability of eye makeup products.

Shampooing is one of the indispensable and attractive services in barbershops and beauty salons. Hairdressers have to repeat shampooing over and over every day, and shampooing often causes a burden to hairdressers. Therefore, we developed a new shampoo technique which is characterized by moving the fingers in a kneading motion, and is different from the conventional shampoo technique that moves the fingers in a scrubbing motion. The purpose of this study was to assess effects of both the kneading shampoo technique and the scrubbing shampoo technique with various psychological and physiological indices of the practitioners and the recipients. In this study, an experiment for shampoo practitioners and an experiment for shampoo recipients were conducted separately. As a result, for the shampoo practitioners, the scrubbing shampoo technique increased a feeling of fatigue with Visual Analogue Scale (VAS), brachioradialis muscle stiffness, heart rate, and skin surface temperatures of forehead and tip of nose, but no significant difference was observed in the kneading shampoo technique. For the shampoo recipients, the kneading shampoo technique showed an increase in the salivary secretory immunoglobulin A (sIgA) level, and decreases in systolic blood pressure and pulse rate. These results suggested that the kneading shampoo technique is very useful, because it could reduce the burden for practitioners and also improve the comfort for recipients. Thus, our study would contribute to improvements in hairdressers' working environment by reducing the burden of shampooing, and in the quality of their services by providing more comfortable feelings to shampoo recipients.

The stress reduction effect of aroma has attracted attention. In this study, this effect of the aroma of fermented cosmetic ingredients was verified by physiological and psychological measurements. A new fermentation liquid was used as a test material. Whey, which is presently used as a cosmetic ingredient, was fermented with yeast (Wickerhamomyces pijperi). The fermentation liquid contained eight different aroma compounds and had a fruity aroma. Twenty-eight healthy volunteers underwent an arithmetic stress task (Uchida-Kraepelin test) and were then allowed to rest. The changes in physiological and psychological stress indicators were examined during the stress and rest periods. The aroma was inhaled three times, i.e., before, during and after the test. Heart rate variability, palm perspiration and salivary stress markers were measured as the physiological indicators. Subjects' moods were measured by the profile of mood states (POMS) test and 2-dimensional visual analogue scale test as the psychological indicators. Water was used as the control. Results showed that the group that inhaled this fermentation liquid had significantly reduced stress-induced increases in palm perspiration and increases in the Confusion-Bewilderment score of the POMS test. These results indicate that the aroma of this novel fermentation liquid has a stress reduction effect in terms of both physiological and psychological parameters.

Amino acid-based surfactants, which have an amino acid residue as a hydrophilic moiety, are widely used for shampoo formulation because of high detergency and low irritancy. However, it's not easy to develop shampoo with ideal foam volume as well as elasticity by using amino acidbased surfactants as a main detergent. So we decided to synthesize a new surfactant, an N-Acyl-N-(2-hydroxyethyl)-β-alanine amino acid-type surfactant (HEA) with a hydroxy group in amino acid residue, and this surface chemical and its physicochemical properties in aqueous solution were investigated. HEA showed unique interfacial behavior around CMC. However, it was not clear that this behavior is due to the hydroxy group. So we used NMR measurement to compare it with an N-acyl-N-methyl-β-alanine amino acid-type surfactant (LMA) without a hydroxy group to understand its behavior in the aqueous solution of HEA. According to the result of NOESY (NMR using the Nuclear Overhauser Effect (NOE)) at 1 mmol/L, inter-molecular correlation was observed between the hydroxyethyl group and lauroyl group of HEA. On the other hand, it was not observed in LMA. The results suggested that formation of hydrogen bonds affect the unique behavior of the HEA solution. HEA was superior to LMA in terms of foam volume, fineness, elasticity and stability. These performances of HEA are thought to result from the formation of hydrogen bonds by having a hydroxyl group on amino acid residue. HEA is a useful detergent for shampoo formulation, and the shampoo with HEA has excellent foam performance.

Skin flora consists of various types of bacteria. It has been reported that skin flora is involved in the maintenance of skin homeostasis. Previous studies have revealed that glucan oligosaccharide (GOS) improves the growth of beneficial bacteria and inhibits the growth of pathogenic microorganisms in the intestines. It is possible that the selective effect of GOS is useful for improving facial skin flora. In this study, we investigated the effectiveness of α-GOS on facial skin flora in clinical trials. For this test, gel formulations including α-GOS were prepared and then applied on the entire face of volunteers twice a day for 2 weeks. Facial skin flora was collected with a wet swab before and after the sample treatment and its composition was analyzed by metagenomic analysis using DNA sequences. The Simpson index (SI) is an indicator of the microbial diversity of facial skin flora. The results showed that the SI was specifically improved in the group of volunteers with low initial SI. Furthermore, the abundance ratios of Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus) tended to increase and tended to decrease, respectively, with the treatment with α-GOS in all subjects. In the group of volunteers with low initial SI, the increased tendency of abundance ratio of S. epidermidis became clear and Cutibacterium acnes (C. acnes) was shifted to the optimal abundance ratio. In conclusion, these results suggest that α-GOS might contribute to the regulation of facial skin flora by improving the balance of beneficial and unbeneficial bacteria and their diversity. Following the modification of facial skin flora in 2 weeks, it would be expected that α-GOS would affect the physiological parameters of the skin. Altogether, α-GOS is expected to be useful as a cosmetic ingredient to regulate facial skin flora.

The proteasome is a large multi-protein complex that plays a central role in protein degradation. Proteasome activity decreases with age, and proteasome inhibition results in increased production of Matrix metalloproteinases (MMPs) and decreased collagen synthesis in fibroblasts. Although proteasome may play an important role in maintaining Extracellular Matrix (ECM) components, there have been few studies investigating the correlation between proteasome activity and synthesis of ECM components other than collagen. To elucidate new mechanisms of sagging on the face with age, we focused on the correlation between proteasome activity and ECM component synthesis. It was revealed that inhibition of proteasome activity reduced gene expression of collagen, hyaluronan synthase and elastin in fibroblasts. This result suggests that proteasome plays an important role in maintaining ECM components. Therefore, a decline of proteasome activity may lead to increased wrinkles and sagging with age. Furthermore, we found that adzuki bean extract had an effect that improved the elasticity of the skin by activating proteasome. Adzuki bean extract effectively increased proteasome activity, collagen synthesis and gene expression of hyaluronan synthase and elastin in fibroblasts. Moreover, it improved the elasticity and tactile elasticity of the face in vivo. Together, the findings suggest that adzuki bean extract increases ECM component synthesis by increasing proteasome activity and that this effect appears even in vivo.