Search Results (3)

2-aza-8-oxohypoxanthine (AOH) has been shown to improve skin barrier function according to DNA microarray studies of normal human epidermal keratinocytes. This study aimed to evaluate the cosmetic efficacy of AOH in wrinkle improvement. A 12-week clinical trial involved 23 women (mean age 44 ± 8 years), who applied 0.01% or 0.05% AOH lotion to each half of their face twice daily. Skin assessments were conducted before and after application at 4, 8, and 12 weeks by measuring stratum corneum water content using a Corneometer and evaluating wrinkles through image analysis of replicas. Application of the lotion enhanced stratum corneum water content. Use of 0.01% AOH reduced the wrinkle area percentage and maximum wrinkle depth at 8 and 12 weeks post-application, respectively. The 0.05% lotion showed a significant reduction in the wrinkle area percentage and mean maximum wrinkle depth at 12 weeks and a significant decrease in maximum wrinkle depth at 4 weeks. A between-group comparison revealed that the 0.05% AOH lotion significantly reduced mean maximum wrinkle depth compared to the 0.01% AOH lotion at 8 and 12 weeks, indicating a concentration-dependent effect of AOH. Overall, AOH improves wrinkles in a concentration-dependent manner, confirming its efficacy as a cosmetic ingredient for wrinkle improvement. Full article

A clinical study was conducted to evaluate the efficacy of 2-aza-8-oxohypoxanthine (AOH) on human skin in a double-blind, placebo-controlled, and split-face comparative trial. To this end, a topical lotion containing 0.1% of AOH and its placebo formulation were applied in 20 Japanese subjects (age: 41–58 years, average: 48.4 ± 4.7 years) to their faces daily for eight weeks. The moisture content in the stratum corneum and the trans-epidermal water loss (TEWL) were measured at the beginning of the study and after eight weeks. The results obtained upon comparing the data of the two measuring points showed that the 0.1% AOH lotion caused a statistically significant larger decrease in TEWL after eight weeks. Moreover, the 0.1% AOH lotion produced a larger increase in the moisture content in the stratum corneum after eight weeks, although there was no statistical difference between the two formulations. These results clearly indicate that AOH is effective as a cosmetic agent with a skin barrier function against water loss. Full article

In this study, we verified the effects of 2-aza-8-oxohypoxanthine (AOH) on human epidermal cell proliferation by performing DNA microarray analysis. Cell proliferation was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, which measures mitochondrial respiration in normal human epidermal keratinocyte (NHEK) cells. Gene expression levels were determined by DNA microarray analysis of 177 genes involved in skin aging and disease. AOH showed a significant increase in cell viability at concentrations between 7.8 and 31.3 μg/mL and a significant decrease at concentrations above 250 μg/mL. DNA microarray analysis showed that AOH significantly increased the gene expression of CLDN1, DSC1, DSG1, and CDH1 (E-cadherin), which are involved in intercellular adhesion and skin barrier functioning. AOH also up-regulated the expression of KLK5, KLK7, and SPIMK5, which are proteases involved in stratum corneum detachment. Furthermore, AOH significantly stimulated the expression of KRT1, KRT10, TGM1, and IVL, which are considered general differentiation indicators, and that of SPRR1B, a cornified envelope component protein. AOH exerted a cell activation effect on human epidermal cells. Since AOH did not cause cytotoxicity, it was considered that the compound had no adverse effects on the skin. In addition, it was found that AOH stimulated the expression levels of genes involved in skin barrier functioning by DNA microarray analysis. Therefore, AOH has the potential for practical use as a cosmetic ingredient. This is the first report of efficacy evaluation tests performed for AOH. Full article