72 ANTI-AGEING
Novel plant growth factor as cosmetic ingredient
Hisae Aoshima - Vitamin C60 BioResearch Corporation ABSTRACT
For centuries, people worldwide have been mystified by the formation of circles or arcs of accelerated or suppressed plant growth in woodlands and grassy fields. These rings sometimes erupt with mushrooms, adding to the intrigue. Myth and superstition led these geometric patterns of plant growth to be called ‘fairy rings’ (Figure 1). Honorary Distinguished Professor of
Shizuoka University, Dr. Kawagishi, discovered the ‘fairies’ were plant growth regulators, 2-azahypoxanthine (AHX), and imidazole-4- carboxamide (ICA) from the fairy-ring-forming and mushroom-forming fungus Lepista sordida and that AHX was converted into 2-aza-8- oxo-hypoxanthine (AOH) in plants (Figure 2).1 AHX, ICA, and AOH are called ‘fairy chemicals’ because they are involved in the formation of fairy rings.
Research at Shizuoka University has
shown that fairy chemicals are natural, safe compounds found in crops such as rice, corn, potatoes, tomatoes, and truffles.2
Considering
the growth-promoting effect of fairy chemicals on plants, the Vitamin C60 BioResearch Corporation (VC60) hypothesized that fairy chemicals could be beneficial for human skin and, from 2018, started joint research with Shizuoka University to apply fairy chemicals as a cosmetic ingredient. Preliminary studies showed that AOH was a promising candidate as a cosmetic ingredient. Therefore, our research has been focused on AOH. In November 2022, we launched Repista
as the world’s first AOH-containing cosmetic ingredient. Prior to its launch, I described the cellular activating effects on normal human epidermal keratinocytes (NHEK) and the DNA microarray results of the AOH active ingredient.3 A clinical trial (long-term continuous-use
study) was conducted to validate the DNA microarray results. Here, I report the results of this clinical trial using a lotion containing the AOH active ingredient. In 2021, an in vitro eye irritation test found the AOH active ingredient to be non-irritating. Therefore, the safety test results are relevant and will be presented again here.
Figure 1: Fairy rings PERSONAL CARE April 2023
Product information The AOH active ingredient is a water-soluble cosmetic ingredient containing 1% AOH (Figure 1). As a new cosmetic ingredient, the AOH was
Vitamin C60 BioResearch Corporation has developed 2-aza-8-oxohypoxanthine (AOH) as the first plant growth factor to be used as a cosmetic ingredient under the trade name Repista®. AOH is found in edible plants in small quantities, so a method for producing AOH at an industrial level was developed, producing a high-purity (>99.9 %) product. Previous results of the cellular activating effect and DNA microarray studies suggest that the AOH active ingredient may improve skin barrier function by promoting epidermal turnover, differentiation, and maturation and by stimulating the metabolism of old skin cells. The results of the present long-term continuous use study of applying the AOH active ingredient lotion facial cosmetic to a group of healthy Japanese women showed an increase in stratum corneum water content in the AOH active ingredient-applied group after eight weeks. Transepidermal water loss (TEWL) in the AOH active ingredient-applied group decreased significantly. Furthermore, analysis of skin lightness revealed that the L* value of the AOH active ingredient lotion group increased significantly after eight weeks, while no statistical change was observed in the placebo lotion group. The increase in stratum corneum water content, decrease in TEWL, and increase in skin lightness were suggested to be due to the ability of the AOH active ingredient to improve skin barrier function.
given an INCI name (Table 1). The AOH in the active ingredient is extremely pure (>99.9%). The appearance of the product is shown in Figure 3.
Clinical trial of the AOH active ingredient Clinical trial formulation The composition of the clinical trial formulation is shown in Table 2. Prior to the clinical trial, a challenge test and patch test with the formulations listed in Table 2 were performed to establish whether the antiseptic effect of the test formulation was sufficient and it was a safe product.
Selection of subjects Subjects who met the following selection
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