Transdermal Absorption of Sclareol, an Active Ingredient in Clary Sage Oil: A Complementary and Alternative Medicine for Menopausal Symptoms

Abstract

Clary sage oil is commonly used in complementary and alternative medicine to treat menopausal symptoms. However, whether sclareol, which is considered to have estrogen-like effects, can be absorbed transdermally remains unknown. Therefore, in this study, we applied sclareol dissolved in jojoba oil to the dorsal skin of male Hos-HR-1 mice 30 min before blood sampling. We examined whether sclareol can be detected in the plasma because of transdermal absorption using gas chromatography-mass spectrometry analysis. The concentration of sclareol in plasma and liver samples calculated based on the measured sample concentration and the recovery rate was 0.36 ± 0.08 and 1.69 ± 0.32 ppm, respectively. Furthermore, there was a significant positive correlation between the plasma sclareol concentration and hepatic homogenate sclareol concentration. Our findings indicate that sclareol is absorbed transdermally and accumulates in the liver. Moreover, the lack of change in plasma blood urea nitrogen, aspartate aminotransferase, and alanine aminotransferase levels among the three groups indicates that there was no hepatic or renal damage due to transdermal absorption of sclareol in Hos-HR-1 mice. However, further validation in humans is required because the thickness of the dermis and the number of pores significantly differ between mice and humans.