Efficacy and safety of fairy compounds, which are new cosmetic ingredients

 Vitamin C60 Bioresearch Co., Ltd. is a new cosmetic ingredient that the company is developing for practical use at the 39th Annual Meeting of the Japanese Society of Cosmetic Dermatology / Academic Conference (July 31st to August 1st, 2021). We made a presentation on the efficacy and safety evaluation research results of 2-aza-8-oxohypoxanthine (AOH), which is called a fairy compound, and received the Excellent Presentation Award.

There is a phenomenon in which mushrooms grow after the turfgrass in parks and golf courses grows in a ring shape or the growth of turfgrass is suppressed (Photo 1). In the Middle Ages, there is a myth that a fairy dances on the mushroom, and it is called a fairy ring in English. However, the reason why such a phenomenon occurs has remained a mystery for a long time.

In 2010, Professor Hirokazu Kawagishi of Shizuoka University discovered 2-azahypoxanthine (AHX), a substance that promotes the growth of turfgrass, in the culture solution of Lepista sordida, a type of mushroom that forms fairy rings. Later, 2-aza-8-oxohypoxanthine (AOH) was discovered as a metabolite of imidazole-4-carboxamide (ICA), which suppresses the growth of turfgrass, and AHX. Citing "Fairy Chemicals" from Nature, which covered these substances, the three compounds have come to be called "fairy compounds." More recent research has revealed that fairy compounds are also found in the three major grains (rice, wheat and corn) and vegetables.

 As a result of preliminary studies, it was found that AOH is the most suitable substance for cosmetic raw materials among the three types, and we have been conducting research focusing on AOH. We summarized the research results on efficacy evaluation and safety evaluation necessary for commercializing AOH as a raw material for functional cosmetics and presented it at this conference.

When AOH was added to human cells, it was found that AOH activates epidermal cells. Therefore, we verified the effectiveness of AOH on the skin by performing DNA microarray analysis * 1. As a result, it was found that AOH is likely to strengthen and improve the skin barrier function. When a human efficacy test (clinical test) was conducted, the water content of the stratum corneum increased by applying 0.1% AOH for 8 weeks. Furthermore, it was revealed that TEWL * 2, which is an index showing the amount of water evaporation from the skin, decreased statistically significantly. The results of clinical trials provided evidence to support the results of DNA microarrays.

 In recent years, from the viewpoint of animal protection, animal experiments to evaluate the safety and effectiveness of cosmetics and cosmetic ingredients have been prohibited. Therefore, we verified the safety of AOH by conducting in vitro safety tests and human tests in accordance with the OECD * 3 test guidelines * 4. No toxicity was observed in all safety tests conducted, confirming the high safety of AOH.

From the above results, AOH is considered to be a highly effective and safe functional cosmetic ingredient as a promising skin care ingredient for maintaining skin homeostasis by acting on the skin barrier function. Registration of the INCI name * 5 and cosmetics label name required to sell AOH as a cosmetic ingredient has already been completed (Fig. 2). In addition, we have developed a technology to manufacture high-purity AOH with a purity of 99.9% or higher, established a manufacturing method, and plan to start sales in 2021. Cosmetics containing AOH are expected to keep the user's skin healthy and beautiful.