Cannabidiol Application Increases Cutaneous Aquaporin-3 and Exerts a Skin Moisturizing Effect

Cannabidiol (CBD) is a major nonpsychotropic component of Cannabis sativa with various pharmacological activities. In this study, we investigated the skin moisturizing effect of CBD and its mechanism. A 1% CBD solution was applied daily to skin of HR-1 hairless (Seven-week-old, male) for 14 days. The dermal water content in CBD-treated mice was significantly increased compared to that in the control group. Furthermore, no inflammatory reaction in the skin and no obvious skin disorders were observed. The mRNA expression levels of loricrin, filaggrin, collagen, hyaluronic acid degrading enzyme, hyaluronic acid synthase, ceramide degrading enzyme, and ceramide synthase in the skin were not affected by the application of CBD. However, only aquaporin-3 (AQP3), a member of the aquaporin family, showed significantly higher levels in the CBD-treated group than in the control group at both the mRNA and protein levels. It was revealed that CBD has a moisturizing effect on the skin. In addition, it is possible that increased expression of AQP3, which plays an important role in skin water retention, is a contributor to the mechanism. CBD is expected to be developed in the future as a cosmetic material with a unique mechanism.