The lips are a prominent part of the face along with the eyes, and their shape and color can affect the impression of the face. In terms of the color of the lips, the most common concerns were whitish, thin, dull, and the difference in color between the upper and lower lips. It is also recognized that the color of lips become lighter and duller with age, but the thinner shape makes it difficult to measure the color precisely with conventional instruments.

In this study, we measured the color of vermilion part of the upper and lower lips of 765 volunteers (aged 15–74) in winter using a non-contact measurement device. Of which 162 were reassessed in summer in order to investigate seasonal changes.

Since lip color tends to gradually lower brightness, redness, and yellowness with age after 30s, it was considered as one of the aging sign. In addition, it was confirmed that the lower lip color changes more with age than the upper lip. Sun exposure habits and seasonal change did not affect much the color of lips, but smoking habits suggested that lip color was greatly influenced by blood flow.

There was a moderate correlation between the brightness of the lips and skin (cheek), but no correlation was found for other color values. It was confirmed that lip color was not affected by water content.

It was found that there were three types of lip color among Japanese women, but there was a difference between the actual color values and the self-assessment.

Daily infection control against COVID-19 infection are causing new skin symptoms on the face and hands. Dermatitis and acne due to non-woven masks, which are optimal for prevention, tend to occur easily if the skin barrier function cannot be maintained normally. Intractable hand eczema is caused by hand washing and disinfection, and gloves are used for the purpose of protection, but treatment is difficult because daily infection control must be continued. If rashes on the face or fingers do not heal easily, protective products may be aggravating factors, so a patch test should be performed to find out the cause. There is a possibility that irritation and allergic reactions due to new chemical substances have occurred due to changes in lifestyle. In order not to cause skin symptoms, each individual needs to continue appropriate cleansing and moisturizing measures according to their own skin quality.

Cosmetics products are daily necessities, and new functional ingredients and products are being developed under corporate social responsibility. Globally, a wide variety of cosmetics are sold in brick-and-mortar and online stores. The quality and safety of the cosmetic products and raw materials must be ensured so that they do not present any risk to consumers. Additionally, consumers must be aware of the potency of cosmetic products. Therefore, establishing standards and testing methods are essential to evaluating the quality, safety, and efficacy of cosmetic products and raw materials. This report introduces the concept of regulatory science research in cosmetics, including market surveillance to ensure that products comply with applicable cosmetic standards and studies on establishing guidelines and standard testing methods for ingredients and trace impurities in cosmetics and quasi-drugs. The promotion of regulatory science research will lead to the development of safe and functional cosmetics per international standards and contribute to enriching human health and the environment.

The epidermis is the outermost layer of the living organism and the first site of contact with external stimuli such as ultraviolet light and microorganisms. Among the cells that make up the epidermis, melanocytes play a wide range of roles besides producing melanin pigment, including absorption of UV light, regulation of body temperature, and protection from foreign enemies through camouflage. Melanocytes also function as antigen-presenting cells that modulate immune responses, and pigmented lesions have been observed in diseases related to immunodeficiency such as Hermansky-Pudlak syndrome, indicating a common molecular action between the endosomal formation of immune system cells and the melanosomal mechanism of pigmented cells. The melanin-producing action of melanocytes requires the maturation of melanosomes, which are endoplasmic reticulum structures, and the control of transporters and endoplasmic reticulum transport associated with melanosome maturation requires regulation in response to external stimuli.

My group has studied how skin pigmentation is affected by genetic background and skin microenvironment. For the genetic approach, we conducted a genome-wide association study (GWAS) of Japanese skin types using data from the Tohoku Medical Megabank Cohort Study and identified OCA2 and other genes as Japanese skin type-related genes. To investigate the effects of skin microenvironment on skin pigmentation, we also examined whether innate immune stimulation via toll-like receptors (TLRs) affects melanin synthesis and melanosome trafficking. We identified TLR3-RAB27A axis and TLR2-RAB11A axis, which enhance melanosome release from melanocytes. In this paper, we summarize these results and describe the impact of innate immune machinery molecules on melanin production mechanisms.

Currently, the toxicity evaluation of chemical substances is conducted mainly based on the results of animal experiments, but from the viewpoint of animal welfare and development efficiency, the development of alternatives to animal experiments is highly required. To this end, many studies are conducted to understand the toxicity mechanism and to construct in vitro testing systems based on the mechanism. In addition, due to its high throughput, the development of an in silico method using machine learning technics with chemical structure information as alternatives to animal experiments is also attracting great attention from researchers. Since the toxicity of some chemical substances is caused by their metabolites, the development of in vitro and in silico evaluation systems that consider drug metabolism is also required. However, current toxicity evaluation systems do not necessarily consider drug metabolism. In this article, I will introduce our recent findings on the importance of drug metabolism consideration in chemical toxicity evaluation using in vitro and in silico methods.

There are various types of side effects caused by cosmetics; mostly they are believed to be not serious. Further, there are not a few cases at present that it is difficult to identify which ingredients in cosmetic products caused; even it was certainly caused by cosmetics which had been used. Table 1 shows not only the actual cases which were implemented some measures by MHLW (Ministry of Health, Labour and Welfare of Japan) under the jurisdiction of Pharmaceutical Affairs Law or JCIA (Japan Cosmetic Industry Association) as a representative of cosmetic industries, taking into account the cases must be caused by cosmetics (including quasi-drugs such as medicated cosmetics), but also covers the background and history of cosmetics regulation under the Pharmaceutical Affairs Law in considering the safety of cosmetics.

In this article, simple consideration is done on Melanosis Faciei Feminea which has developed social problem that health damage is caused by cosmetics. The process in pigeonholing a part of this case is investigated from an ethologic perspective. Furthermore, a lawsuit on melanosis and simple description on Berlocq Dermatitis are mentioned.