Dry skin in the winter is related to the ceramide profile in the stratum corneum and can be improved by treatment with a Eucalyptus extract
Correspondence: J Ishikawa, Biological Science Laboratory, Kao Corporation, Haga-gun, Tochigi, Japan. E-mail: firstname.lastname@example.org
Dry skin in the winter has been reported to involve scaling, defects in water holding and barrier functions, and decreased ceramide (CER) levels in the stratum corneum (SC). We previously reported that a Eucalyptus extract promotes CER synthesis in cultured keratinocytes and accelerates the recovery of hydration in a barrier-disrupted model of human skin.
One of the objectives was to examine the CER profile and its contribution to the relief of dry skin. The other objective was to assess the efficacy of a Eucalyptus extract to treat dry skin.
Twenty subjects with dry skin on their legs were assessed and their CER profiles were analyzed using tape-stripping. A moisturizer with a Eucalyptus extract was assessed for its effects on dry skin using a leg regression methodology comprising 28 days of treatment and 14 days of regression.
Indicators of dry skin conditions (conductance, dryness, roughness, and scaliness) strongly correlated with the level of CER, CER [NP], and CER[NH]. Treatment with the Eucalyptus extract significantly improved conductance (3 days after regression) and transepidermal water loss (14 days after regression) compared with the placebo. After 28 days of treatment with the Eucalyptus extract, the level of CER in the SC did not increase, but CER [NP] did increase.
These results suggest that not only the level of CER, but also specific CER species strongly contribute to dry skin relief and products that increase those are useful to improve dry skin conditions.